‘ , . v. y . . . alkgw 3.091 b2. 3.1.3.5..- .02. 7.5“; c . \3 3.. v www: .3 a3: . .. I. J. ‘7 7. . y ‘ u u k , . Date 0-7639 .37 This is to certify that the thesis entitled NHITEFLY (l. vagor‘ar‘ium, Nest.) PREFERENCE 0N THREE BEAN GENERA OF THE FAMILY LEGUMINOSAE. presented by FREDDY R. ALONZO-PADILLA has been accepted towards fulfillment of the requirements for P h . D degree in En tomol oq y Major professor (j) OVERDUE FINES: 25¢ Per day per item RETURNING LIBRARY MATERIALS: Place in book return to remove charge from circulation records FREDDY R. ALONZO-PADILLA A DISSERTATION Submitted to Michigan State University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Entomology 1980 ABSTRACT HHITEFLY (Trialeurodes vaporarium Nestw.) PREFERENCE OF THREE BEAN GENERA OF THE FAMILY LEGUMINOSAE By Freddy R. Alonzo—Padilla Hhitefly (Trialeurodes vaporarium Nestw.) prolificacy and hioh survival attributes enable it to fully infest the leaf underside of the host plants. As a suckino insect, it stunts the growth of bean plants due to the enormous losses of plant sap. The adult mobility and habit of feeding in the phloem enables it to be an efficient vector of several virus diseases. The purpose of this research was to evaluate ll8 bean cultivars of four species of Phaseolus, two species of Viona, and one species of Dolichos lablab, for shelter and oviposition preferences to the Greenhouse whitefly in free-choice greenhouse conditions. A second purpose of this research was to study leaf-part preferences exhibited by adult whiteflies when confined to selected cultivars of the three Genera with varying degrees of resistance. A satisfactory method for testing bean dermplasm for whitefly resistance was developed, as suggested by the highly significant (P=0.0l) correlation coefficient found between cultivar plant responses recorded in the free-choice nermplasm test versus those plant responses recorded in the experiment of plant part and adult preferences. The highest resistance for whitefly adult attraction and/or for oviposition was found in genera other than Phaseolus. Within the Phaseolus this resistance was also higher in species other than Eh, vulgaris. Both Vigna radiata, Dolichos lablab and E, repens in decreasing order of preference, were the least preferred. In the Phaseolus germ plasm, the degree of attractiveness was in general shown in the following ascending order: first, Eh. coccineus and Eh, lunatus, second, Eh. accutifolius, and third, Eh, vulgaris. In all these genera and species, the highest level of resistance was associated with low attractiveness shown by the first well expanded leaf blade of the upper plant part, and with the almost non-attract- iveness of the shoot. Shoot non-attractiveness was a fairly common phenomena except in the preferred and very preferred cultivars. In the Eh, vulgaris group, wild types seemed to be the best source of breeding material for resistance to this insect, although Eh. lunatus and Eh, coccineus were sources of resistance, and successful crosses of these with Eh. vulgaris have been reported in the literature. Seed coat color of-Eh. vulgaris was suggested to be related with whitefly adult attraction and with oviposition preference. The plants of some black and red seeded types were least preferred for shelter and/or for oviposition, but plants of the striped seeded types were the most preferred. Somewhat intermediate in attractiveness were some brown and white seeded cultivars. Hhitefly adults confined to the most resistant cultivars were observed to greater extent on leaf parts such as the petiole and stem, as well as on the chamber wall, which are unusual parts selected by the whitefly adult in normal conditions. law I _ my“: Inula man aulgsasdq brr. wank-3'3: .-'"-. nae-:5 metro 'mi'e'.-_.:-,.r. [mil-“iii: -r-'--_°. r:- ~ ~- _b—-—c—-- -— - :i ."If _ -.- . 'l I _. Short flights, as part of the normal whitefly behavior were also taken less often in the most resistant cultivars. The shoot, the petiole and the stem exhibited only l8, l6 and 2 percent, respectively, of the adult attraction shown by the first well expanded leaf blade alone. Confining conditions of the whitefly adult leaf-part preference study allowed identification of cultivars exhibiting non-preferred responses even under greater infesting pressure. The author would like to dedicate this thesis to the following persons. The small bean-peasants of the world. Mr. Manuel Alonzo and Mrs. Victoria Padilla de Alonzo. (Love and deepest gratitude to their multiple efforts). Nolandth Elizabeth, Itze Victoria, and Freddy Rolando (Jr.). (My lovely children) it ACKNOWLEDGEMENT The author would like to express gratitude to Dr. J. A. Webster, his major professor, first for allowing him to continue working on this project he had started in the Institute of Science and Agricult- ure Technology of Guatemala where he worked as entomologist of the bean program. Indebted is also the author to him for the greenhouse space, some material facilities and for computer time received, through his person, as a grant from the USDA-Cereal Leaf Beetle Program. Without these valuable facilities this research would not have been possible. Special thanks are due the members of comittee Dr. J. A. Webster, Dr. R. Ruppel, Dr. E. Grafius, and Dr. M. W. Adams for their valuable criticism in the writting of this thesis. A special note of gratitude goes to Dr. J. Bath, chairman of the Department of Entomology, for his spontaneous will in helping the author to obtain both his AID-fellowship and his Michigan State University student admision. Indebted is the author for the same reason to his major professor, Dr. J. A. Webster. Indebted and grateful is the author to the Agency of International Trainning (AID), and the Institute of Science and Agriculture Techno- logy of Guatemala, for financial support which enabled him to complete his studies. in 3932695! .A .b .10 oz! abufrl'zme name on 3m bitiW mums 9H? " ' . .. .' . ' 'r. n .. 1' . .__'._.,., ."|' "a |‘1.'|.',,‘_".L-' : [I'll If“. '. ' .1 "rf'. l‘r‘r-T. I 1'. ' a . . :i..’h r. "'.-._ . _.-'1~_':' 7 v. ..'" -".l ' - Sincere appreciation is extended to his better half, Sonia, who has been at his side throughout this rewarding period. Thanks are due also to all those persons that in any way contri- buted to complete this thesis, and the author studies. iv TABLE OF CONTENTS Page LIST OF TABLES .......................... vi LIST OF FIGURES .......................... ix INTRODUCTION ........................... 1 LITERATURE REVIEW ......................... 3 SELECTION OF BEAN CULTIVARS FOR RESISTANCE AGAINST THE GREENHOUSE WHITEFLY (Trialeurodes vaporarium WESTW.) IN GREENHOUSE CONDITIONS ....................... l2 Introduction ......................... l2 Materials and Methods .................... l2 Results and Discussion .................... l9 GREENHOUSE WHITEFLY (I, vaporarium WESTW.) ADULT PREFERENCE FOR SEVERAL PLANT PARTS OF Phaseolus, nggg, AND Dolichos BEAN SPECIES ........................... 44 Introduction ......................... 44 Materials and Methods .................... 44 Results and Discussion .................... 47 SUMMARY AND CONCLUSIONS ...................... 72 REFERENCES ............................ 78 APPENDIX ............................. 83 I I I I I I I l I I -J I an.- .—-.. .1. < I I o I I I I I I I I I I I I I 10. ll. LIST OF TABLES Analysis of variance of whitefly adult preference, and of oviposition preference readings (l—5) for the ll8 bean cultivars evaluated . Correlation coefficients between adult attraction and oviposition readings for the five adult-resistance groups of cultivars and for the ll8 bean cultivars evaluated. Statistics describing the whitefly scale (larval) pop- ulation from the first release of adults in replicates I and II . . . . . . . . . . . . . . . Statistics describing each observed resistance category either for adult preference or for oviposition preference. Bean cultivars categorized as non-preferred for whitefly adult attraction and their seed coat color . Bean cultivars categorized as moderately non—preferred for whitefly adult attraction, and their seed coat color . Eleven Eh, vulgaris categorized as the least inter- mediately preferred for whitefly adult attraction, com- pared with the cultivar most preferred in the same class, and their seed coat color. . . . . . . Thirteen most attractive bean cultivars in the preferred category of adult attraction, and their seed coat color. Six bean cultivars (Eh, vulgaris) categorized as very preferred for adult attraction, and their seed coat color. Percentage of Eh. vulgaris in five classes of whitefly adult preference according to their seed coat color. Bean cultivars classified as non-preferred and moderately non-preferred for oviposition and their seed coat color. i/i' Page . 20 . 24 . 25 . 27 . 29 . 3O . 32 . 33 . 35 . 36 . 37 pus .9'Jnfi’!9"?9"lir flute I‘ 231m.- enwx-‘w ': a":--"a"-"-. 8"TEE-‘"|:"l.1-lj --_.... - " "" '.' 3"” " l2. l3. l4. l5. l6. l7. l8. l9. Zl. 22. 23. Thirteen Eh, vulgaris classified as the least inter- mediately preferred for whitefly oviposition, compared to the most highly preferred cultivar in the same class, and their seed coat color .............. Five Eh, vulgaris cultivars classified as the most attractive in the preferred category for whitefly ovi- position and their respective seed coat color. . Thirteen bean cultivars classified as very preferred for whitefly oviposition and their seed coat color . Percentage of Eh, vulgaris in five classes of whitefly oviposition preference according to their seed coat color. Analysis of variance of leaf part effect upon whitefly adult attraction . . . Significance of the analysis of variance (F-values) for cultivars, leaves, leaf parts and chamber effect upon whitefly adult attraction. Analysis of variance of leaf-part and cage wall effect upon whitefly adult attraction . . . Student-Newman-Kneuls multiple range mean test of five treatments for whitefly adult attraction, relative percentage of adult attraction value (both of arcsine transformed data), and true observed leaf-part mean values (%) of adults . Correlation coefficients between adult attraction values registered for the overall variety adult-attraction with leaf-blade attraction, and between leaf-blade with the adult attraction observed by the shoot, the petiole, and the chamber. Percentage of adults on each leaf-part and chamber wall in cultivars of the non-preferred class for adult attraction . Percentage of adults on each leaf-part and chamber wall in cultivars of the moderately non-preferred class for adult attraction . Percentage of adults on each leaf-part and chamber wall in cultivars of the intermediately preferred class for adult attraction . vii Page . 39 . 40 . 42 . 43 . 48 . SO . 54 . 55 . 56 . 63 . 64 . 66 24. Percentage values of adults on each leaf-part and chamber wall in cultivars of the preferred and the very preferred class for adult attraction . 25. Correlation coefficients between the adult attraction values observed in each cultivar in the screening experi- ment and the corresponding mean varieties and leaf blades in the adult leaf preference experiment ...... viii Page . 67 . 7O 9013 has 2mm in: fut-a -_-.r'.J n‘r LIST OF FIGURES Growing stages of bean-plants at (A) first release (15 days old) and (B) second release (25 days old) . . . . Growing stage of bean-plants at third release (35 days old . . . . . . . . . . . ..... . . . ...... Aspirator apparatus used to collect whitefly adults. Cold box used for transporting whitefly in plastic cylinders. Frequency of bean cultivars in each whitefly: adult (A), and oviposition (B) preference class . . Bean plant showing the two leaf types studied in the leaf— part attraction experiment; (A) first not fully expanded trifoliate leaf (shoot), (B) two first well expanded leaflets . . . . . . . . . Frequency of bean cultivars in two hsd-groups. A=groups according to mean variety effect; B=according to variety first well expanded leaf effect; C=according to variety- shoot effect; D=according to variety-petiole effect; and E=according to variety-chamber effect. . . . Mean percentage of whitefly adult on each leaE, leaf-part and on the chamber, and their significance (X ) in attraction between resistance classes. . Percentage of bean cultivars in each resistance category with adult attraction to the leaf, leaf-parts, and the chamber, and their significance (X2) in attraction between resistance classes . ix Page . l5 . l6 . l6 . l7 . 2l . 46 . 5l . 58 . 6O INTRODUCTION The importance of the greenhouse whitefly, Trialeurodes vaporarium (Westw.), as a greenhouse pest is well known. Its importance as a vector of virus diseases is also well documented (IS, 52, 37). Breeding bean cultivars for genetic resistance against either the greenhouse whitefly (Trialeurodes vaporarium Westw.) or the more tropical bean whitefly (Bemisia tabaci Gen.) provides an ideal way of controlling or suppressing their physical damage. Breeding for genetic resistance probably greatly reduces the frequency with which bean plants show virus diseases. There are several supporting facts for this author's hypothesis: (l) virus disease transmission is confined to the adult life stage, the only non-sedentary whitefly life stage; (2) the adult whitefly's speci- ficity as a phloem-feeder enables this to be the only stage efficiently transmitting virus diseases; (3) adult whiteflies take a relatively long time (T5 minutes or more) to reach the phloem in Eh, lunatus (53); (4) viruses in the whitefly adult require a relatively long incubation period (more than 8 hours) for the adult to become a positive vector; and (5) congenital virus transmission has not been demonstrated (53). Genetic recombination of either resistance or tolerance against whitefly transmitted diseases and to the vector would certainly decrease the genetic vulnerability of bean cultivars to insect transmitted diseases. The intrinsic advantages of studing whitefly-host resistance as a method of control revolve around a minimum production cost and a minimum disturbance caused to the balance between destructive insects and their natural enemies in contrast to pesticide dependent systems. Another advantage is that no environmental or food contamination would result from using such a method of control for whiteflies. It should also be emphasized that this method is exceptionally compatible with all other control measures. This research was conducted in greenhouse and laboratory conditions. The purpose was to: (l) detect sources of resistance against the whitefly in three bean genera (Phaseolus, Eighg, and Dolichos), all members of the family Leguminosae; and (2) to discover possible adult behavior preferences when exposed to different genera or cultivars with varying degrees of resistance. LITERATURE REVIEW Family Leguminosae Characteristics: About l2,000 species are reported to be members of the leguminosae (ll). Leguminosae members are dicotyledoneous plants with hypogynous or perigynous flowers. The androecium has 3 to lO stamens that may be united or free. The corolla either zygomorphic or actinomorphic, has 4 to 5 petals united or free, but 5 united or free or 2 united and 3 free are also common. Also the calyx is of 4 to 5 petals, and also united or free. The fruit is a typical bibalved legume (8, ll, 44, 49). Plant genera used in this thesis as experimental units are all members of the Dapilionatae sub-family. They are identified by their papilionaceous flowers, that is, with the upper petal or standard exterior (44, 49). Phaseolus, Eigha and Dolichos, the genera tested, are all members of the section Phaseoleae having leaflets pinnately 3 foliolate and not stipellate, but, they are differentiated by some flower, pod and seed features. Genus Phaseolus: This genus is botanically distinguished from Viqna by having a spirally twisted keel, and from Dolichos by the stigma being oblique instead of terminal (44, 49). The calyx of Phaseolus is campanulated or short and tubular, with the upper segments united or free holding 4 an orbicular standard. Wings of the flower are erect and ovate shaped, rarely oblong, but add to the keel beyond the claw. The keel has a long, obtuse, spirally twisted beak. The upper stamen is free and thickened at the base or with appendages. The style is long, thickened within the beak of the keel and twisted with the latter. Both annual and perennial plant types are winding or postrate, rarely somewhat erect herbs, with a liqneous base and tri-foliate leaves. The flowers are disposed in axil— ary racemes of white, yellow, violet, red, or purple color (ll, 42, 44). Features that differentiate species of Phaseolus are also related with flower and pod characteristics. Phaseolus vulgaris (L) - the flowers, 1.5 to 2 cm long, are pale purple or pink, and white, and the pods are swollen and less than l.4 cm wide (8, ll, 42, 44). Phaseolus lunatus (L) - the flowers, less than T cm long, are a greenish-yellow color, and the pods, l.5 to 2 cm wide, are broad and flat (8, ll, 44). Phaseolus coccineus (L) - the racemes are TS to 20 cm long or longer. The flowers, about 2 cm long, are red or white. The pods are distinct- ively thicker, with seeds that are larger than Eh. vulgaris in nearly all their dimensions. In contrast to Eh. vulgaris and Eh. lunatus, the cotyledons are hypogeous in germination (ll, 42, 44). Phaseolus accutifolius (L) - the flowers are white or pale purple. The pods are compressed and cylindrical, containing up to six seeds that are particularly elliptic or oval. The seeds are small, usually less than 0.5 cm in diameter and without radial nervure (ll). Oenus Vigna: The calyx is campanulate or somewhat tubular, and the upper two segments may be free or united. The keel, almost as long as the wings, is truncated, or beaked, at the tip but not spiral. The flowers are greenish-yellow, rarely purple, and disposed in axillary racemes. The pod is characteristically linear, straight or slightly recurved, 2-valved and filled between the seeds. The seeds are reniform or quadrate. The plant type is either postrate and twining, and sometimes, though rarely erect. The leaves are pinnate bearing three leaflets with stipules usually more persistent (42). V. repens - the flowers, l2 to 20 in number, are disposed in a conical raceme on a glabrous peduncle 5 to To cm long. The corolla is pale yellow and ll to T3 mm long. The pods are fairly glabrous, 3.7 to 5 cm long, 6 mm broad, and thinly silky containing 8 to ID seeds of shiny brown color with a white hilum (42, 44). .E. radiata - the flowers are about I cm long, yellow and racemosely arranged near the end of the short pubescent pedunculus. The pods are pubescent and linear, 6 to 8 cm long and about 6 mm wide, bearing seeds 4 to 6 mm long. It is an erect or climbing annual herb, branched from the base, and clothed with brownish hairs. Leaflets are acuminate and 8 to TS cm long (ll, 44). Genus Dolichos: Dolichos lablab (L) - the calyx is campanulate with short segments, and a united upper part. The wings are curved, but the keel is very much incurved. The flowers are white, yellowish or pale purple, usually disposed in small racemes. The pod is linear, very much compressed, straight or curved, and usually with thickened margins. The seeds are thick and compressed with a linear, fleshy arillus (ll, 42, 44). GREENHOUSE WHITEFLY Origin and significance: The insect, popularly known as the greenhouse whitefly or snowfly (Trialeurodes vaporarium, West. Aleyrodidae: Homoptera), is native of Brazil, but found throughout the world (30). According to Russel (T963), T44 genera of plants are hosts of this whitefly, which is predominately found on hosts having rather thick sappy leaves, such as the french and runner beans (29, 30, 47). Although the so called greenhouse whitefly and larvae are very small, they occur in such immense numbers that the plants become impoverished and the quality of the fruits decrease. The entire undersides of leaves are often completely covered with the scale-like larvae and pupae (2T, 47). Hussey et al (25), pointed out that up to 20 scales per cm2 may be toler- ated on tomatoes before whiteflies adversely affect yield. However, in ornamentals, a much lower density is tolerated (22). The potential of the greenhouse whitefly to cause damage is also related to its ability to transmit virus diseases (l5, 52, 23). I, vaporarium was reported by Duffes (l5) as being the vector of the beet pseudoyellows virus in California. The same species has been reported by Trasversi (52) as being the vector of a sunflower virus in Argentina. T. abutilonea was identified in Maryland as the vector of sweet potato yellow-dwarf virus (23). Life cycle: Whitefly metamorphosis, is somewhat intermediate between complete and incomplete: four larva or scale-like instars and the adult stage. All larval instars, except the first one which is temporarily a crawler, are sedentaries, wingless, and resemble scales (l3, 2l, 29, 47). On a susceptible pinto bean cultivar, l2 to TB hours after the early fourth larva instar, it undergoes changes that resemble a pupa stage (author's observations). When these changes take place, its dorsal skin becomes chitinized and leathery in appearance. Considerable growth in depth as well as adult differentiation takes place at this time (l0, l2, 2T, 29, 37, 53). The developmental history of whiteflies, as in other insects, is influenced by several factors, among which host and temperature are perhaps the most important (author's experience). In a greenhouse test with young bean plants at 23.3OC, hatching time took between 8 to lO days. The duration of the first stage was 5 days, the second 2 days, the third 3 days, and the fourth stage 8 days (30). Unfortunately the adult life span was not recorded, but the life of both male and female on tomato plants was 34 and 39 days, respectively. Adult: The adults are very small sucking insects. When reared on a suscept- ible pinto dry bean cultivar, the males measured l to l.2 mm long and 0.4 to 5 mm wide; the females measured l.3 to l.8 mm long and 0.5 to 0.7 mm wide (measurements done by author). Mating of the adults takes place soon after emergence from the pupa, usually on the same leaf on which they emerge (2T, 29). The male generally rests quietly by the side of the female and mates repeatedly. Although repetition of coitus appears unnecessary, it has been observed to occur between the same pair up to five times (21). Parthenogenesis has been observed to be a common phenomena in whiteflies (21, 30, 36). Oviposition: Oviposition generally begins on the second to the fifth day after adult emergence. The undersides of young leaves are preferred for ovi- position, though occasionally other green plant parts may be used (21, 30). Eggs are generally laid in incomplete circles of about 1.5 mm diameter. The female inserts her stylet into the leaf tissue and using that point as the center and the body as radius, deposits each egg into a small cut porperly made (21, 30). The average number of eggs reported by Lloyd was 130, but the largest observed was 534 on Lamium purpureum (a kind of weed), one of the 18 plant hosts studied (30). Egg: Greenhouse whitefly eggs are stalked, the stalk being short and partly imbedded in the tissue of the leaf (21, 30). The length of the stalk measures about 0.02 mm, with the total length of the egg being about 0.24 mm (21). Eggs are greenish when first deposited and are covered with wax produced by the adult. After two to four days they begin to darken, turning from the original yellowish green to brown, and finally to black (21, 22). Just prior to hatching (ten to thirteen days after oviposition), a crack appears near the unattached end of the egg on its concave side, and the larvae emerge about seven minutes later (21). Scale or larvae: All four larval instars, except the first one, are totally sedentary. The first larva stage shows a kind of movement that is considered non-mig- ratory movement. It is usually confined to the first hours of life and is usually only a sufficient distance for the scale to grow without coming in contact with others from the same batch (21, 30, 37, 53). All larval stages are distinctively flat after the molt. Since the dorsal skin of the fourth larval stage becomes heavily chitinized and leathery in appearance, it is nearly always referred in the literature as being the pupa. But, at the beginning of the instar it is similar to the larva of the preceding instar (10, 21, 22, 37). When the adult emerges from the mature scale, the empty shell is left attached to the leaf (21, 22, 37). Host plant resistance: Insect host plant resistance, according to Beck (7), is defined as the heritable characteristics by which a plant species, race, clone, or individual may reduce probability of successful utilization of that plant as a host by an insect, species, race, biotype, or individual. This kind of resistance is usually made up of varying degrees of one or more compon- ents: non-preference and preference, antibiosis, and tolerance (40). In the consulted literature for the last 30 years, no paper related to the screening of bean—cultivars for whitefly damage and possible mech- anisms of resistance was found. . —i"-- If - ‘E g. I ‘ iflsfal‘tua I {Tao tlfcuau at 'V “:5 .YE .TE .lfii’dasac ems: 9g: moat east?“ dilw resingn n' I 59“.. _-‘_-_:E -'1_::_.-—, s: h .-._I .-‘. l_ . :ani'. -. .- 1.. _ .‘J.’ _ ". .._' .' h ‘1:- IO Preference or non-preference: Leafhopper preference for different plant colors for feeding or for oviposition has been reported in alfalfa, clover, soybeans and in several species of Phaseolus (6, 38, 43, 46, 54, 55). Physical characteristics, mainly those related to leaf pubescence density and/or its characteristics, have most often been associated with such insect preference or non-prefer— ence. Preference of the whitefly for less hairy tomato and poinsettia plants has also been observed (9, 16, 19, 26). Though other factors may be more important at close range, vision, phototaxis, geotaxis, and hydrotaxis are the most often reported clues directing insects to the proper environment for feeding and for ovipos- ition (2, l4, 17, 34, 35). Whitefly preference for feeding and oviposition on yellow, yellow- green and white substrates, as well as the undersides of young leaves, and especially for those of thick sappy hosts are phenomena often reported in the literature (3, 9, 20, 21, 22, 32, 37, 47, 51). Resistance of certain plant tissues to puncturing has also been reported as a resistance mechanism to sucking insects for certain legume varieties (46). Antibiosis: All adverse effects on the normal biology of the insect when it uses a resistant host plant variety as host are included in this category of resistance (17, 39). This kind of resistance is often due to toxins or other antibiotic agents, to the absence of some nutritional materials, and to the imbalance of available nutrients (31, 35, 41). Saponins, ll sugarznitrogen ratio, and the differential presence or absence of specific carbohydrates have been found to have detrimental effects on several insect pests of legumes (4, 5, 18, 24, 31, 33). Tolerance: Tolerance is a sometimes disputable category of resistance that was originally introduced by Painter (39). Tolerance, stands for the ability of a plant cultivar to reproduce itself or repair injury to a marked degree in spite of supporting a population equivalent to that damaging a susceptible host (40). This kind of response has been shown by some legume cultivars when exposed to damaging sucking insects. Alfalfa culti- vars that are susceptible to the pea aphid have shown more pronounced stunting than tolerant varieties (40). Some cowpea strains have also exhibited such reactions against the hopperburn injury caused by leaf- hoppers (55). SELECTION OF BEAN CULTIVARS FOR RESISTANCE AGAINST THE GREENHOUSE WHITEFLY (Trialeurodes vaporarium WESTW.) IN GREENHOUSE CONDITIONS Introduction Despite the wide number of insecticides available to horticulturists and farmers, whiteflies continue to be one of the major economic pests for greenhouse and crop production around the world. Many of the affected plants are succulents, and like beans, are used as food crops. Since good persistent chemical control of the whitefly (T. vaporarium or of B. tabaci), has not been found in beans with the broad number of insecticides tested, it would be desirable to have resistant cultivars, and thus lower whitefly population levels. Failure to find specific literature about bean-screening experiments against whitefly damage and/or its possible mechanisms of resistance, in- dicates that information about these topics is scarce or lacking. The purpose of this research was to evaluate 118 bean cultivars (four species of Phaseolus, two species of Eighg, and one of Dolichos lablab) for shelter and oviposition preference by the greenhouse whitefly. Materials And Methods Screening of the cultivars was done in greenhouse conditions from July to September, 1978, at a mean temperature of 260C and a 12 hour 12 13 photoperiod. The experimental bean plants consisted of 109 Phaseolus vulgaris (L), two Eh, lunatus (L), three Eh, coccineus (L), one Eh, accutifolius, one Vigna repens, one Vigna radiata (=Eh, aureus), and one Dolichos lablab. Most of the common dry bean entries were selected from the 2,200 entries evaluated in Guatemala for resistance to the whitefly, Bemisia tabaci (Genn), and to the leafhopper, Empoasca sp. The entries were selected based on either their high preference on non-preference ratings. The ratings were based on the number of nymphs and adults under natural and artificial infestations when the plants were 30 and 45 days old (1). Similarly, the other species, except Dolichos lablab, were selected on the basis of the author's criteria that different plant and leaf characteristics could cause different whitefly response. Though the same criteria were followed in the addition of Dolichos lablab, it was received from Dr. S. Wellso, (U.S.D.A., Michigan State University), who found it in Honduras, C.A. Cultivars previously evaluated in Guatemala were obtained from the International Institute of Tropical Agriculture, in Colombia. A few Eh, vulgaris were brought by the author from the College of Agriculture of Mayaguez in Puerto Rico. Three Eh. vulgaris entries were also received from Dr. W. Adams, (Dept. of Crop and Soil Science, Michigan State University), as being very susceptible to the leafhopper. A complete randomized design (3 reps per cultivar) was used. Each experimental unit was a bean plant in a 13 cm diameter clay pot in the soil mixture (1 sandzl peatzl topsoil) used in the Michigan State University plant science greenhouse. 14 To avoid differences in attraction mainly due to plant differences in color caused by soil fertility differences, the soil in each pot was fertilized twice, 2 and 30 days after germination, with one gram of 12-12—12 fertilizer. Two seeds per pot were sown in order to guarantee a uniform population of one plant per pot. There were three artificial infestations, 15, 25 and 35 days after planting (Figures 1 and 2). Different arrangements of plant varieties within each replicate before each release time was done to expose each plant cultivar to a different plant neighbor effect. Whiteflies, reared for at least five generations on a susceptible pinto-bean cultivar, were used for infesting purposes. The whitefly adults were collected with an aspirator and a collector assay tube (Figure 3). Insects were inactivated by exposure for 15 min— utes in a refrigerator at 00C. Plastic cylinders, with a foam ring in the opening of the tube, were used to confine the whiteflies prior to infesting each experimental unit. The whiteflies, in the plastic cylin- ders, were carefully transported in a cold ice box (Figure 4) to prevent re-activation before the cylinders were distributed between the pots on the grenhouse bench. This prevented infestation of the cultivars with- out a previous whitefly orientation, probably toward the cultivars more preferred. To avoid bias, care was taken in placing a single cylinder of whiteflies at the same distance from each plant. Mean infestation rates per plant for first, second and third releases were 35, 45, and 55 insects in the first replicate, and 34, 35, and 158 in the second and third replications. Data relative to adult preference were taken 60 hours after each infestation. The total whitefly population on each cultivar was recorded. Figure 1. Growing stages of bean—plants at (A) first release (15 days old), and (B) second release (25 days old). 16 Figure 3. Aspirator apparatus used to collect whitefly adults. 17 Figure 4. Cold box used for transporting whitefly plastic cylinders. adults in 18 Recapture of the adults was done during counting by using the aspirator. Much of the work was done during the night when the adults were relatively immobile. Data relative to oviposition preference were taken twenty days after each infestation time; a visual rating scale of: (l) non-preferred, (2) moderately non—preferred, (3) intermediately preferred, (4) preferred, and (5) very preferred was used for this purpose. Oviposition readings were based on the relative abundance of the scale numbers all over the entire plant. Counting the number of scales per cultivar from the first release in the first and secg1d replicates was done to know numerical values as a reference for the classes. The same rating scale from 1 (non—preferred) to 5 (very preferred) was also followed to categorize germplasm for adult preference. The five resistance classes for adult preference were defined as follows: (1) non-preferred (lowest trans- formed mean value + l hsd—valLe), (2) moderately non-preferred (lowest transformed mean value + 2 hsd-values), (3) intermediately preferred (lowest transformed mean value + 3 hsd-values), (4) preferred (lowest transformed mean value + 4 hsd-values), and (5) very preferred (lowest transformed mean values + 5 or more hsd-values). Analysis of variance, simple correlations, statistics describing populations, and graphic techniques were used to discriminate varietal effects, and to present results relative to adult and oviposition preferences. RESULTS AND DISCUSSION To determine the statistical significance of both adult and ovi- position preferences, analysis of variance of the mean number of adults (square root transformation) attracted by each cultivar and of the mean oviposition values were calculated (Table 1). There were highly sig- nificant differences (P=0.01) among cultivars for adult and oviposition preference and between blocks. The blocks were probably significantly different because infestation rates per plant in the first release were different from those in the second and third replications. Another possible cause of this significant block effect was that they were tested one at a time, due to space and time limitations. Al- though attempts were made to maintain controlled conditions, differences in time could have exposed replications to minor changes in soil, temp- erature, photoperiod (sunlight hours); plus a different generation of test insects and perhaps unconscious small changes in methodology could also have affected them. Figure 5 shows the frequency of cultivars falling into each of the adult (A), and oviposition (B) classes of preference. In the adult preference test, 5.9 percent of the cultivars were non-preferred, 10.2 percent were moderately non-preferred, 34.7 percent were intermediately preferred, 33.9 percent were preferred, and 15.2 percent were very pre- ferred (Figure 5A). In the oviposition test 5.9, 4.2, 37.3, 41.5, and I9 20 Ho.oua pa ocaoeaacovm ta mmm _agoe mm.o we.m emm Laced .. 4m.m wN.N a. oe.m mm.wH NHH maa>_p_:o I. mm.mfl we.wa as Hm.efl aa.flm N mxuo_m a m: a m: aucaeca> .caca ._>o .luuilllnlmmwmmlwflmmfiulllllllll cc to moazom .waszw>w mcm>ep_:o camp wHH mgu cow Amlfiv mmcwvmmc wocmcwwwca 20.5.5830 do vcm .A 333 do .oz: 858me :23... 343.23 to cocci? U5 mwmimé .H 293 Figure 5. Frequency of bean cultivars in each whitefly: adult (A) and oviposition (B) preference class. Number of cultivars Number of cultivars 50 4O 22 1= non-preferred 2= moderately non-pref. 3= Intermediately pref. 4= preferred 5= very preferred 23 11.0 percent were in the same classes of preference for oviposition (Figure SB). Correlation coefficients between adult attraction and oviposition preference readings for the 5 adult preference groups of bean cultivars, and for the 118 bean cultivars tested, are reported in Table 2. A highly significant correlation (P=0.01) was found only for the 118 tested bean cultivars. The significance level for the 118 bean cultivars shows that, on the average, oviposition preference positively correlated with adult attraction. The negative correlation detected for cultivars very pre- ferred by adults, though not statistically significant, suggests that extremely crowded adult conditions on leaves of the especially preferred cultivars, inhibited to some degree either individual and/or general ovi- position capabilities. Such inhibition could be due to the increasing competition for space for feeding and oviposition. Statistics describing the scale population from the first release of adults in replicates I and II are shown in Table 3. Mean rank of scales for the oviposition preference classes were found to be: from 1.0 to 14.0 scales for the non-preferred class; from 9.5 to 58.0 for the moderately non-preferred class; from 55.0 to 117.5 for the intermediately preferred class; from 109.0 to 272.5 for the preferred class; and from 153.0 to 325.5 for the very preferred class. Overlapping of ranks is possible since the real discrimination of cultivars into single categories of preference was based on mean oviposition ratings values (1 through 5) which were merely visual readings. Mean oviposition values per cultivar were 4.5, 25.0, 104.3, 170.8 and 230.0 scales, respectively, for each class of resistance, assuming equal percent of survivorship. The highest 24 Sana pa 2853.5 .3. oemm.o- ma umccmewLQI>em> m¢¢N.o ow coccmwmcm Nmmm.o Hv . umccmwmca cwuwscmacH mwflm.o NH wmccmwmea-:o: >prpmcwvoz qumfi.o N coccwdwcq-coz ** ommo.o wHH mcm>_p_:olcmmm Umpmwe L umcmasoo Lonazz azocw .cmpc:_m>w mgm>wu—:o :mwn wHH msu Low use mcw>wppzo do mgzogm mocmpm_mwclp—sue w>ww asp Log mm:_uwmc co_pvmoq?>o ucm :o_poccuum “Faun cmmzpmn mpcmwowgmoo coemeocLou .N open» AAA mm.mv 00.0mm m.mmmno.mmH mH vwcewwmga >Lo> 8.: £5: mmaéafi: 9. Stats 3.8 8.42 9E8? 3 Stats 3838.585 8.: 8.3 0.336 m 8:89.98: 38.28% 0H.m om.¢ o.¢Hlo.fi N noccmemca-coz .o.m :mwz xcwm mLm>wu—:u mwmpu wucmpmwmmm mmpcom to Lonasz go cmassz .HH ecu H mmowo?_amc cm mu_:ua do wmmm—mc pmcww ecu Eoce cowpm_:aoa A_c>cm_v oFmom >_gmu_:3 on» mcwnwcommv mo_umwumpm .m o_nmp 26 deviation was in the non—preferred and the moderately non—preferred classes, while the remainder of classes were fairly uniform in variabil- ity. “ban rank values per cultivar for the different classes of resist- ance for adult preference (Table 4) were: from 1 to 7 adults for the non-preferred; from 13 to 43 for the moderately non-preferred; from 40 to 85 for the intermediately preferred; from 70 to 110 for the preferred; and from 100 to 203 adults for the very preferred class. Mean values were 4, 30, 57, 86, and 138 adults, respectively, for each category (Table 4). The mean rank for each resistance class for oviposition varied from 1.00 to 1.18, from 2.00 to 2.50, from 2.53 to 3.50, from 3.53 to 4.43, and from 4.57 to 5.00, respectively, for the non-preferred, moderately non—preferred, intermediately preferred, preferred and for the very pre- ferred class. Mean values of each class were 1.04, 2.26, 3.13, 3.86, and 4.71, respectively. In Table 4, the magnitude of the standard devi— ation values shows fairly uniform plant response in each class of resist- ance. Highest deviation was observed in the adult non-preferred class, and the lowest was found in the very preferred class for oviposition. In the adult preference test 7, 12, 41, 40, and 18 cultivars fell in the non-preferred, moderately non-preferred, intermediately preferred, preferred, and very preferred classes, respectively. In the oviposition test, 7, 5, 44, 49, and 13 were respectively in the same resistance classes. Selected bean cultivars showing different levels of preference to the whitefly adult are presented in Tables 5 through 9. The highest level of adult non-preference was found in genera other than Phaseolus. 27 Table 4. Statistics describing each observed resistance category either for adult preference or for oviposition preference. Class of resistance Range Mean S.D. Adult Preference: Non-preferred 1.11-7.00 4.18 2.05 Moderately non-preferred 13.00—43.33 30.14 9.32 Intermediately preferred 40.00-85.33 56.77 11.88 Preferred 70.00-110.33 86.62 14.28 Very preferred 110.33-203.00 138.49 27.08 Oviposition preference: Non-preferred 1.00-1.18 1.04 0.07 Moderately non—preferred 2.00-2.50 2.26 0.20 Intermediately preferred 2.53-3.50 3.13 0.29 Preferred 3.53-4.43 3.86 0.26 Very preferred 4.57-5.00 4.71 0.13 28 Within the genus Phaseolus, attractiveness to the whitefly adult was also lower in species other than Eh. vulgaris. Seven cultivars were assigned to the non-preferred class (Table 5). Both Vigna repens and y, radiata cultivars ranked highest in the non-pre- ferred class (1.11 and 2.67 adults, respectively). However, G00127 (Eh. lunatus), G00046 and G00038 (both Eh. coccineus), H-00126 (Dolichos lablab), and G01154 (the other Eh. lunatus) were somewhat more attractive to the whitefly adult (3.17, 4.00, 5.33, 6.00, and 7.00, respectively). The moderately non-preferred class, except for Eh. accutifolius, consisted exclusively of 11 Eh, vulgaris cultivars (Table 6). This might be expected since 92.4 percent of the entries tested were Eh, vulgaris. This reasoning would also hold true for the intermediately preferred and very preferred classes. Three black seeded Eh, vulgaris, the wild type G00132 with 13 adults, G03645 a selection of Jamapa, and PI-309-804 both with 19 adults ranked least preferred in the moderately adult non-preferred class. This suggests that wild types of Eh, vulgaris, and among them perhaps the black types, would probably be the best sources of higher levels of white- fly adult non-preference. Perhaps black seeded types have been exposed more often to other genera of whiteflies or to other insects with similar feeding habits in the more tropical countries. However, the author has observed nearly all seeded types growing in the low lands of Mexico (in Sonora, Sinaloa, Veracruz, and Yucatan), in Guatemala, in El Salvador, in Honduras, in Nicaragua, in Costa Rica, in Panama, in Colombia (in Cali), in Venezuela (in Bolivar), in Puerto Rico, and in the Dominican Republic as well as in intermediate and high altitudes. 29 .mcmms quLoemcmcu asp op mcwceooow umpLOm men mean: Lm>wp_su + owes: 00.x ammmmmmfl ummv qmfiflow Emwcu 00.9 AmmmmMH.WMQMHHmmV omfioo: czocm zmvuvwm mm.m dwmmmflmmmw ammv wmoooo 55$ 5483. 8.4 A? .flv $88 8.2: :5 £683 .5: R88 58c N: Aalommwfl 34.1.5 $88 53$ :4 Ag 3V $88 Lopoo mu_:um to + Lm>wp_:u Hmoo mem .02 :mwz .Lo_oo pmoo Ummm cmmgp vcm covpomgpum p_:vm zpwmpesz Low cmccmgocglco: mm cmecommHmo mcm>PpF=o comm .m mpnwe 30 Table 6. Bean cultivars categorized as moderately non—preferred for whitefly adult attraction and their seed coat color. Mean No. Seed coat Cultivar + of adults color 000132 (Eh. vulgaris, Wild) 13.00 Black 003645 (Eh. vulgaris) 19.00 Black PI 309-804 (Eh. vulgaris) 19.00 Black Porrillo No.1 (Eh. vulgaris) 42.00 Black 004485 (Eh. vulgaris) 35.67 Black 004487 (Eh, vulgaris) 27.33 Black 000787 (Eh, vulgaris) 29.33 Red G03244 (Eh. vulgaris) 31.33 Black 001222 (Eh. acutifolius) 31.67 White 002980 (Eh, vulgaris) 32.67 Black 003097 (Eh, vulgaris) 43.33 White Porrillo sintetico (Eh. vulgaris) 37.33 Black + Cultivar names are sorted according to the transformed means. 31 004487 (black), 000787 (red), and 003244 (black) were other Eh. vulgaris entries which were preferred less than Eh, accutifolius (001222). 001222 ranked sixth in the moderately non-preferred class with 31.67 adults. Porrillo sintetico (a black seeded synthetic variety and ranked ninth), as expected showed a better performance as moderately non-preferred, than what was exhibited by Porrillo No. 1 (ranked tenth), which is a line. Twelve Eh, vulgaris cultivars in the intermediately preferred class are listed in Table 7. Pinto-114 (striped), 15R-52 (black), and 000129 (black), had the lowest attraction values. The highest attractiveness in this class was found for the cultivar 003195 (black). Some Eh, vulgaris of the black, red, and white seeded types were mostly in the non-preferred and moderately non-preferred classes. Thus, it appears that in this species, and in this test, black and red types in ascending order of preference showed higher adult non-preference than white and striped types. Table 8 shows 12 of the most preferred Eh, vulgaris entries assigned to the preferred class for adult attraction. One Eh. coccineus (000039) in this category is also included in the table. A very susceptible leaf- hopper Eh, vulgaris variety, 1-59 (light brown seeded), was also one most preferred by whitefly adults, which suggests that common mechanisms of susceptibility might be involved. The four following it in ascending order of preference were 004525 (black), 703 (black), Rayada (striped), and 001225 (striped). The presence of Eh, coccineus (000039) in this class compared with the presence of the other two Eh, coccineus (000046, and 000038) in the 32 Table 7. Eleven Eh, vulgaris categorized as the least intermediately preferred for whitefly adult attraction, compared with the most preferred cultivar in the same class, and their seed coat color. adults Cultivar + No. Pinto-114 40.00 15R-52 49.67 000129 41.00 004481 42.00 002983 43.33 Brazil-2 46.00 002977 46.67 Venezuela-2 45.67 003108 48.00 S-116-A-N 49.33 002960 46.00 003195 85.33 Seed coat color Striped Black Black Black Black Light brown Black Black Black Black Black Black + Cultivar names are sorted according to the transformed means. 33 Table 8. Thirteen most attractive bean cultivars in the preferred category of adult attraction and their seed coat color. No. of Cultivar + adults 000039 (Eh. coccineus) 90.00 Red Kidney (Eh. vulgaris) 123.33 003178 (Eh. vulgaris) 132.00 003050 (Eh. vulgaris) 124.67 003167 (Eh. vulgaris) 129.00 003242 (Eh, vulgaris) 127.00 003252 (Eh. vulgaris) 125.33 003645 (Eh. vulgaris) 132.33 1-59 (Eh, vulgaris) 136.33 004525 (Eh. vulgaris) 110.33 703 (Eh, vulgaris) . 109.67 Rayada (Eh. vulgaris) 109.33 001225 (Eh, vulgaris) 110.33 Seed coat color Reddish brown Red Brown Black Black Black Brown Black Brown Black Black Striped Striped + Cultivar names are sorted according to the transformed means. 34 non-preferred class shows the broad genetic variability in this species for whitefly adult attraction. The six most preferred Phaseolus vulgaris entries placed in the very preferred category of adult whitefly attraction are reported in Table 9. In descending order of preference, 000718 (striped), 003101 (black), 004494 (striped), 001054 (dark red), 001083 (striped) and 001204 (white), were in this class. The place that striped seeded types occupied in this category suggests that they are perhaps the most pre- ferred by adults. The Eh, vulgaris entries were also placed in the five resistance categories according to seed coat color (Table 10). Eighty percent of the brown seeded types and 58% of the striped seeded types were in the preferred and very preferred classes of adult attraction. As observed in Tables 5 through 10, as well as in the appendix, in the Eh. vulgaris species, some black, some red, and some white seeded types were less attractive to the whitefly adult. Thus, it is suggested that in this test striped and brown seeded varieties of Eh. vulgaris were apparently most preferred by the whitefly adult. This result might be due to the pres- ence in the leaves of differential precursors of tanins, to their differ— ential concentration and/or to the differential presence of pigments which later determine the seed coat color. According to the visual oviposition ratings (1 through 5), taken 20 days after each infestation, seven cultivars were classified as non-pre— ferred (Table 11). The highest non-preference for whitefly oviposition was found in genera other than Phaseolus. This non-preference reaction was also 35 uaa_28m x8a_m eaaaepm 0am eaaweem 833:3 copoo “moo comm .mcmwe nmELowmcmLu asp ow mcwncooom cmpLOm mew mmsm: cm>wp_:u + mm.mom wfiaoow mm.me Hommow No.wmfi amqeow mm.amfl emofioo oo.©mH mmoflow mm.flmfi womficw me_:ea + ea>ep_=u do .02 .Lofioo uwmw vmmm Leon“ 6cm cowp -omcuum apnea Loo cmgcmwmcq >cm> mm vawcommpmo Am_eac~:> .sav mcm>wp_:o camp xwm .m mPQGH 36 NH mm.mm 00.0w m0.H¢ 00.0 00.0 eaQHme mcw>Hsz0 Ho Longsz vaccwcha xcm> Umecwwwca umecmwwca .HcH coccmwmcaucoc .uoz coccmwmcq-coz 0 H H 0H N Hm 00.NH 00.0 00.0 00.0w 00.Nq N0.HH 00.0 00.0 00.00H 00.00 00.0 00.00 0m.m0 00.00H 00.0 00.0w 00.Nv Hm.mm 00.0w 00.0 00.0 00.0 00.0 00.NH 00.0 00.0 00.0 00.0 00.0 00.0 I I - u u l n l l l l x I u n l l l n - - l l I mpwzz wHacsm waccco czocm tom xomHm xgmu >Lw> ;m_EmmL0 LOFOU #000 wam wocmpmwmmm .LoHoo Hmoo comm chgu on 0chcooom wocmcwwmca pHsnm AwaHH:z we mommeo m>Hw :_ mHmeHz> amm we mmmucmocma .0H mHan 37 Table 11. Bean cultivars classified as non-preferred and moder; ately non-preferred for oviposition and their seed coat color. Cultivar Non-preferred: 001154 (Eh. lunatus) 000127 (Eh. lunatus) H00126 (Dolichos lablab) 000037 (Vigna repens) 000128 (Vigna radiata) 000046 (Eh, coccineus) 000038 (Eh. coccineus) Moderately non—preferred: 000129 (Ph. vulgaris) 000132 (3h. w. Wild) 001222 (Eh, accutifolius) 000787 (Eh. vulgaris) 003244 (Eh, vulgaris) Mean Reading/ cultivar 1.00 1.00 1.00 2.16 Seed coat color White White Cream Brown Green Reddish brown Reddish brown Black Black White Red Black 38 highest in species of Phaseolus different than Eh. vulgaris. A fairly identical non-preferred response of 1.00 was recorded for Vigna repens (000037), V. radiata (000128), Eh, lunatus (001154 and 000127), the Dolichos lablab cultivar, and both Eh, coccineus (000046 and 000038), which had oviposition ratings of 1.13 and 1.18, respectively. Eh, vulgaris cultivar was not in this resistance category. Only four Eh. vulgaris—~000129 (black), 000132 (black), 000787 (red) and 003244 (black), and the Eh, accutifolius (001222, white seeded and in place No. 3)--were in the moderately non-preferred class for whitefly oviposition (Table 11). Since no striped seeded or white seeded Eh, vulgaris cultivars were again in this non-preferred class for ovi— position, it is suggested that black and red seeded cultivars of this species were the least preferred for oviposition than cultivars having seeds of other colors. There were 44 Eh, vulgaris cultivars in the intermediately preferred class for oviposition. The 13 least preferred and the most preferred cultivar (004485, black) in this class are reported in Table 12. The four least preferred cultivars in this resistance class, were: 15R-52 (black), Pinto (striped), 000773 (white), and PI-309-804 (black). Porrillo sintetico (black), 002980 (black), Porrillo No. 1 (black), and 004485 (black) were also in this category, despite the fact they were moderately non-preferred for adult attraction. There were 49 and 13 bean cultivars, respectively, in the preferred and very preferred classes for oviposition. Two striped seeded cultivars (001225 and 000718), one white seeded (000808), and two black (003115 and 003167) showed the highest attraction for whitefly oviposition in the preferred class (Table 13). 39 Table 12. Thirteen Eh. vulgaris classified as the least intermedi- ately preferred for whitefly oviposition, compared to the most highly preferred cultivar in the same class, and their seed coat color. Cultivar Mean Ovip. Reading Seed coat color 15R-52 2.53 Black Pinto 2.57 Striped 000773 2.70 White PI-309-804 2.70 Black 003645 2.73 Black Sanilac 2.80 White Black turtle 2.83 Black Porrillo sintetico 2.83 Black 005706 2.90 Black 002980 2.90 Black Porrillo No.1 2.90 Black Pompadour-Z 2.93 Striped 002977 2.97 Black 004485 3.50 Black thus M. w n .1. w ._ .h . mxofim 8.4 $88 was: 8.4 288 wag: m: 888 wwfibm 8.4 238 1.823 . one 028 vaou Lm>wquo Lm>HHH=0 echo mmom \0cH0mwm new: :0; . a... ... .eemo “moo comm o>Haomammg ewes» 0cm coHpHmoQH>o Awapwcz Low zmMmzuao .omp cm o>wuoasaum umos any we coH$HmmmHo mem>Hquo mwgmmH=> .50 m>Hu .mH mHQMH 41 The most preferred cultivar for oviposition in the very preferred class was 001204 (white) which was also very preferred for adult attract- ion (Table 14). Following it were 002997 (black), Rayada (striped), and 1—59 (brown seeded and very susceptible to leafhopper). Eh. coccineus (000039), a preferred cultivar for adult attraction, was also one of the most very preferred for oviposition (Table 14), thus showing again the broad genetic variability in this species for whitefly resistance. The Eh. vulgaris entries were also placed in the five preference classes for oviposition according to their seed coat Color (Table 15). The striped and brown seeded types were the most preferred by whitefly for oviposition. Some black and some red seeded cultivars were found to be the least preferred for whitefly oviposition. Some white seeded culti- vars seemed to be somewhat intermediate in their attractiveness, but brown types were more preferred than white ones (see also the appendix). Creamy orange and very dark purple seeded cultivars (one of each), were in the preferred class for oviposition, despite the fact that the very dark purple cultivar was only intermediately preferred in whitefly adult attractiveness. Thus, based on the supporting facts previously mentioned about the apparent seed coat color relationship with whitefly adult attraction, it is suggested that the greatest attractiveness for oviposition was also found in cultivars with striped seed coats, but highest non-preference was observed in some black and red seeded cultivars. 42 Table 14. Thirteen bean cultivars classified as very preferred for whitefly oviposition and their seed coat color. Cultivar 001083 (Eh. vulgaris) 003099 (Eh. vul aris) ) f 004494 (Eh. vulgaris 003242 (Eh, vulgaris) 003128 (Eh. vulgaris) 003252 (Eh, vulgaris) 002987 (Eh. vulgaris) 000039 (Eh. coccineus) 003050 (Eh, vulgaris) 1-59 (Eh. vulgaris) Rayada (Ph. vul aris) f 002997 ( h. vul aris) i 001204 (Ph. vul aris) f cultivar App-04> bk Mean Reading/ .57 .57 .60 .63 .63 .63 .63 .70 .73 .77 .87 .90 .OO Seed coat color Striped Black Striped Black Brown Brown Black Brown Black Brown Striped Black White 43 NH 0 H H 0H m HR mcm>HHHzo $0 cmaszz 00.0w 00.NH 00.0 00.0 00.0H um.0m <0.m vmggmwmea zem> 00.00 00.0w 00.00H 00.00H 00.00 «Hunm 00.0w 0mLmemLa 00.0w 00.00 00.0 00.0 00.0m 00.0 00.x0 UmLLmHmLQ .HcH 00.0 om.NH 00.0 00.0 00.0 0N.¢H mm.¢ 0mggmwmganco: .002 00.0 00.0 00.0 00.0 00.0 00.0 00.0 UmgcmmeQ-coz I - l - - - - I I I - I- l - I u N u I - I l - - - u - - a n u I . 0mQHLHm mpwsz mHaczm mmcmco :zocm 0mm xomHm museumHme xmmu Hgm> cmHEmmgu we LoHoo Hmoo ummm mmmHu .eoHoo Hmoo 0mmm chcu ow mcHueooom mocmgmemcq :oHuHmoaH>o HHHmHng Ho mmmmmHo m>Hm :H chmmHz> .mm.wo mmmpcmommm .0H manH GREENHOUSE WHITEFLY (E. vagorarium WESTW.) ADULT PREFERENCE FOR SEVERAL PLANT PARTS OF Phaseolus, Vigna, AND Dolichos BEAN SPECIES Introduction In addition to extrinsic environmental influences, insect responses to any oiven host depend on several intrinsic factors of the insect and also on several factors of the host. The better they fit each other, the higher the insect population on a given host is, and the more sus- ceptible the host becomes. Changes in behavior and mechanisms of host selection are areas where insects most often have evolved to adapt to their hosts. A counter response from the host plant directly against the insect pest or its biology often evolves. Host responses leading either to repel, to kill, to tolerate, or to adversely affect the normal growth of the insect are very common. The purpose of this research was to study plant leaf preferences of adult whiteflies when confined to species of three bean genera (Phaseolus, Vigna, and Dolichos) with varying degrees of resistance. Materials And Methods Whitefly adult attraction preferences to two plant leaf levels of 38 bean cultivars with varying degrees of resistance were studied in 44 45 greenhouse and laboratory conditions. There were seven non-preferred, ten moderately non—preferred, nine intermediately preferred, six pre- ferred, and six very preferred cultivars, which were previously identi- fied in the free-choice test of germplasm in the greenhouse. During the winter of 1978-1979, two plants of each experimental unit were grown in the plant science greenhouse. The soil mixture used was 1 part sandzl part peatzl part topsoil. In order to avoid differ- ences in color due to soil fertility differences, the soil in each pot was fertilized 2 and 30 days after germination with one gram of 12-12-12 fertilizer. Two seeds per pot were sown to guarantee one plant per pot. The experimental part of this study was conducted in laboratory con- ditions from January 15 to February 5, 1979, at 250C with 11 hours of light. The two plant leaf levels studies were: (1) the first not fully expanded trifoliate leaf (shoot), (2) and the two first well expanded leaflets. Both leaf types were located at the upper part of the plant (Figure 6). Bean stems bearing the leaves were in glass assay tubes of about 25cc filled with a plant nutrient solution (28). A foam ring in the opening of the tube was used to keep the stems in place. Transparent plastic chambers, 20 cm high with an open base and a removable top with a very fine screen cloth, were used to confine the whiteflies to both kinds of leaves. Wooden racks with holes of the proper size supported the assay tubes and the chambers. Two well expanded first leaflets and a shoot from a single plant cultivar were placed in each assay tube- chamber combination at each test time. Three replications of each plant part were tested. Due to space and equipment limitations, one replication was tested at a time. 46 Figure 6. Bean plant showing the two leaf types studied in the leaf- part attraction experiment; (A) first not fully expanded trifoliate leaf (shoot), (B) two first well expanded leaflets. 47 Plant leaf samples were collected at 15, 25 and 35 days after plant emergence. A whitefly population reared for at least 9 generations on a susceptible pinto—bean cultivar was used for infesting. For the tests, whiteflies were captured with an aspirator. White- flies were then placed in a refrigerator (150C) for a 2-hour starving period. For infesting purposes, insects were inactivated by exposure for 15 minutes in a 00C refrigerator. The infestation rate per chamber was 8 t 2 whitefly adults. Whitefly adult preference data were taken 36 hours after each infes- tation. The number of adults attracted by the shoot, expanded leaf blades, petiole, stem, and the number present in any part of the chamber wall were recorded at the same time. Analysis of variance, honestly significant differences values, the multiple mean rank test (Student-Newlman-Knewls Test), some statistics helpful in describing populations, a previously designed rating scale of classes of adult preference and some graphic techniques were used to discriminate variety, to determine leaf and leaf part effects, and to present the results. Results And Discussion The analysis of variance for the bi-factorial arrangement (culti- vars x location), showed that only location factors and the interaction of cultivars with location factors were significantly different (P=0.01) in adult attraction (Table 16). The non-significant effect found between bean cultivars is explainable since the percentage of adults l-e omit-ei- Fifi-r t . Ho.o "a pa “caUHeHcmHm «a 9"" 000 Hmpoh H¢mo.0 mum coecm . ameH.o meH mx< coHpoaemueH . 00% 000mg: 0 :0 $0520 + 28 Hauling v. . 0000.0 mm AHpH=0 0000.0 N mxuon . . m: .00 mocmmca> mo mocsom » .Humsgowmcmgp mch newuumsuum uHscm AHHmuwgz :o pomwwm Hem; HmmH Ho moceHsm> 0o mmeHmz< .0H mHan - .5.‘ 49 registered in the chamber were also included in the analysis (Table 16) in addition to the plant treatments. But, significant varietal differ- ences at P=0.01 were found in the separate analysis of variance for cultivars as a whole (Table 17). Also, there were significant varietal differences in adult attraction in the 4 separate analysis of variance for the first well expanded leaf blades, the shoot, the petiole, the stem and the chamber (Table 17). The term chamber stands for the number of adults recorded in any place other than on the plant material. The non-significant block effect for nearly all variables analyzed indicates that the methodology was uniform in all treatments, and that there were no differences in leaf-part response due to the different plant ages. This is expected because although the plants themselves were different ages at the different infestation times, the plant parts tested were still in the active growth phase. The significant block effect (P=0.05 level) found only for the ”cultivar leaf-blades" effect, is attributed to variations in adult attraction which was exhibited for some cultivars at different repli- cations (Table 17). Differences in leaf size were a probable cause. A different cultivar neighbor effect could also have been involved since the chambers were fully transparent and there was a different assortment of cultivars in each replicate. The highly significant chamber effect (Table 17) could have been attributable either to a strong attraction effect from neighboring plants, to the presence of a repellent effect of the cultivars within the chamber, or to a combined effect of both. Figure 7 shows the number of groups of cultivars differentiated by adding the hsd—values to the lowest mean transformed value of: 50 mo.o ”a pa pcaonHcmHm w Hod um #0 ucwuwwwcmwm c1” mHH Hmuow 0N coccm kw 00.N m¢.H k0 00.H am 00.N *k 00.N ** 0M0.N mm mLm>HHH30 H0.N 0H.H Nv.N m00.0 * MN.m 00H0.H N mxoon itIllIlIIlllIIiIIlIiiIlIIiIItIllllIlIlIl1IIll1lllIll1lnlIIIlI1IlllIlIlIIllIulllllllllllllllllllllllll tmnEagu ampm mHoHpma poocm meaanamo La>_BH=o we :oHoaHea> IlIIliaIlllII1IIIIIIIlIlIiIIIIIllIIlIlwMmwammmmmwIiIllllllllllillllllllilill wo muesom .HcmELowmcmep mcwmocmmH .mgw>wHH:o cow Hmmsz>-mv mocmwcm> wo mmeHmcm mcu wo mmcmonwcmwm .wH mHnmw 51 25 U‘) L g 20 .5 3 15 q. ° 10 0' Z 5 Least Most Preference group hsd= 0.80 No. of cultivars Least Most Least Most Least Most Preference group Preference group Preference group Figure 7. Frequency of bean cultivars into two hsd-groups A= groups according to mean variety effect; B= according to variety first well expanded leaf effect; C= according to variety-shoot effect; D= according to variety-petiole effect; and E= according to variety-chamber effect. 52 (1) cultivars, (2) the first well expanded leaflets of individual cultivars, (3) the shoot of individual cultivars, (4) the petiole of individual cultivars, and (5) the chamber of the individual cultivars. Only two groups of cultivars were differentiated in each variable that was analyzed for plant part adult attraction. For cultivars as a whole they were 55 and 45 percent, respectively, for the least and the most preferred groups of cultivars (Figure 7A). For the individual values of cultivars of the first well expanded leaf blades they were 63 and 37 percent of cultivars, respectively, for the groups previously mentioned (Figure 7B). In Figures 7C, 7D, and 7E about the same frequency of cultivars were in the most preferred and the least preferred groups for leaf parts and for the chamber. There were 97.4 and 2.6 percent, respect- ively, for the least and the most preferred groups according to shoot attractiveness to the whitefly adult. There were 94.7 and 5.3 percent of cultivars, respectively, in the same groups previously mentioned for petiole attractiveness. And there were 89.5 and 10.5 percent of the cultivars also in the same groups for the number of adults counted in the chamber. The general reduction of groupsobserved in this test compared with the number detected in the free—choice germplasm evaluation experiment, is attributed to the fact that infesting pressure in confining conditions was greater, since there was no alternative for host selection. Con- fining conditions, however, in relation with variety mean values allowed identification of those cultivars exhibiting that non-preferred res- ponse, which is shown even under greater infesting pressure. This is an example of one of the two kinds of non—preference cited by Painter (40). 53 Highly statistically significant differences in adult attraction were also found between the five locations evaluated (Table 18). The chamber, shoot, petiole, and stem accounted for 64, 18, 16 and 2 percent, respectively, of the adult attraction for the first well ex- panded leaf blade. All treatments, except the shoot and petiole were statistically different in adult attraction. Preference for the leaf blade was outstanding (Table 19). Significant positive correlations were found between the overall variety adult attraction values and leaf blade adult attraction values in all groups of resistance (Table 20). Stronger association (P=0 01 level) was found only for the non-preferred and the intermediately preferred classes. The positive correlation found between the variety adult attraction values and the leaf blade adult attraction values is explained, because the first well expanded leaf blades, as shown in Table 19, were the most preferred parts of the plant to the whitefly adult. Although not always significant, negative correlation between leaf- adult attraction values registered in the leaf blades versus those found in the shoot, the petiole, and the chamber were nearly always (73% of the time) observed in all classes. Significant negative association, at P=0.05 between attraction values for the first well-expanded leaf blade and the shoot was found only for the moderately non-preferred and the two most preferred classes (preferred + very preferred). Since the non-preferred class consisted mainly of genera other than Phaseolus, it is concluded that in general the Eh, vulgaris group of cultivars least and most adult d1 m. ...... Ho.o "a He HcaunHemHm we 00H :38 030.0 00H 6.20 , I. «00.0: 080.4 4 HHaz .8286 + 328 wag Hwo.o omoo.o Hm . mxuon m. . m: wH. mocmwcms wo moczom ._ _ .vaHEowmcmLH m: 50.20me 8.53.3 3.33:; .80: uomwwm Zn: mmmo 0.3 0.80.. :wmmH wo 8:2,»? wo $9295 .0H mEmH . HHH... . 55 0m.00 N0.0N 00.0 :mmz mzew -mcmLH mewmocm wo :Honv msHm> :oHHomLHHm Hszm wo mmmpzmocma m>HHmHmc .coHHomcHHm .stHHnanoca mo Hm>mH 00.0 Hm mHnmcmHzacwumHucH meoHHmHHmHm mLm mcmHHmH mEmm mSH 0:Hcmcm mcmme umseowmcmcw 00.00H m ¢HH0.0 0H.¢0 n 0N00.0 00.nH o 0NOH.0 00.0H o «mmH.0 00.H u 00H0.0 & .Hmmsz> .wmcmeH mchoLev m>HHmHmm :mmz .mHszm wo Hwy mmsHm> cams HcmauwmmH 0m>gmmno mscH 0cm .HmHmc cmEcow mumHn wmmm Lmnsmz0 poacm mHoHpma EmHm HcmEmeem Hsze HmeHng Low chmEHmmcH m>Hw wo HmmH :mmE mace; mHQHHHss mHzm¥-:mezmz-Hcm0:Hm .0H mHan 56 RN0.0- LmQEaco 00.0- mHoHpma .m> .m> ¥H0.0- Hoozm .m> mUmHnuwmmH cm>HHH30 wm0.0 mvanuwmmH .m> msz> L3.530 Humgcmwmc Lm>+0mecmwmcm **00.0- LmnEmco .m> .m> 0N.o aHoHHma 00.0- Hoesm .m> mvannwmmH mm>HHHs0 4*N0.0 mvaauwmmH .m> msz> L$.5qu ”0mgcmwmm HmHmvaEcchH L nmumHmLLoo 0:000 mmmw.O| *mm.ol *¢m.o 0000.0: 0m.0 Nm.0 *x00.0 mHmu HcmHonzmcH n--- 00.0 n; Hm HcmonHcmHm * H0.0 um Hm HcmonHcaHm am cmnEmgo .m> mHoHqu .m> Hoozm .m> mvan-wmmH Lm>HHH30 mannuwmmH .m> msz> ca>HHH30 numccmwmc ice: HHmHacmuoz LmDEego .m> mHoHqu .m> Hoocm .m> msz> mvanlwamm mumHnlwme .m> mmzHe> cm>HHHz0 ”cmcemwmcm-:oz cmpmHmLLoo 0:000 .Lmnamso mgH 0cm .mHoHHmQ mgH .Hoozm msH An 0m>gmmao :oHHomLHHm Hszw mgH :HHB mumHnuwmmH :mmzpmn 0:0 .coHHomLHHm mumHnnwmmH SHHZ :oHHomLHHm HHmHLm> Hngm>o mgH Low umLmHmwmmL mmsz> :oHHomLHHm Hqum cmmsza mwcmHonwmoo :oHHaHmLLou .0N mHan 57 preference showed the most consistent negative association in attraction values between leaf blade and shoot. Highly negative association (P=0.0l) between leaf blade adult attraction and the number of whitefly adults in the chamber was found in the non-preferred, the moderately non-preferred class and the intermediately preferred classes. Significant negative association, but only at P=0.05 level, was found for the group of the two highest preferred classes, ( = -O.62). Thus it is also concluded that in the Eh, vulgaris group, there was a tendency of cultivars in the most preferred classes to show greater adult attraction to leaves and less adult attraction on the chamber than in the cultivars in the non-preferred group. Specifically in the non- preferred class, the r-values indicated almost no correlation between leaf blade adult attraction with shoot-adult attraction. i 2 values for the mean The mean percentage values as well as the X adult attraction by each plant part and by the chamber in the five adult preference classes are graphically shown in Figure 8. The first well expanded leaf blades exhibited the highest mean adult attraction values in all classes of resistance. The lowest mean adult attraction values were in the non-preferred class (30%), followed by the moderately non-preferred class (6l%), the very preferred class (6 %), the intermediately preferred class (69%), and the preferred class (7l%). The non-preferred and intermediately preferred classes were the least attractive on the shoot for the whitefly adult, l.75 and 2.76% respectively. They were followed by the moderately non-preferred, the preferred and the very preferred, with 4.88, 6.38, and l2.2l% of the adults attracted, respectively. 58 .mmwmmHu :meHmn :owuumcupa :H ANxV wocmu_chon LHmsu wcm .LmnEmsu new .Hgma-wmoH .wme comm co mqucm HHtmpHsz do wmmucmogma cam: .m mgzmHu mumHnlmmww LwnEmzu Emum mHoHpma Hoosm .me HHmz .HmH m a m N H q N w m N m w m N H m w m N H c3. mHéN n Nx ow 0N coccwemca Hgm> nm em Uwccmwmca ”q es NH.mH u Nx umcgmwmcg HHmHmHumscmch um .wmcalco: Hprmcmcoz uN cmccwymcg-coz nH cm ooH 59 Lowest petiole attractiveness to the adult was observed on the average in the most preferred classes. Fairly similar petiole attract- iveness was observed in the moderately non-preferred and intermediately preferred classes (3.75 and 3.53%, respectively) while the highest mean petiole attractiveness was observed in the non-preferred class (ll.4 %). Stem adult attraction was recorded only in the moderately non—pre- ferred and the intermediately preferred cultivars (l.3 and O.4l%). The highest mean percentage of whiteflies on the chamber was in the non-preferred grOUp (t 56%). In decreasing order were the moderately non-preferred (29%), the intermediately preferred (t 2l%), and the preferred group (: l7%). The x2 values calculated for each leaf part and for the chamber indicated that, except by the stem, all other leaf parts in general exhibited significantly different mean adult attraction values between classes. The percentage of bean cultivars by resistance category with some adult attraction values in the first well expanded leaf blades, the shoot, the petiole, the stem, and the chamber, as well as their X2 values for the respective percentage of cultivars with adult attraction, are graphically presented in Figure 9. One hundred percent of the bean cultivars had at least some white- fly adult attraction to the first well expanded leaf blade, as well as in the chamber wall. The highest percentage of cultivars exhibiting adult attraction to shoots was in the very preferred and preferred classes, lOO and 50%, respectively. But the lowest proportion (33%) was in the intermediate 6O .mmmmmHu moan» -ummL :mmzpwn :oHHooLuum :H H VoucmonH:mHm Lngp new .cmaawco use .pcwalwmmH .wmmH mgu ow :OHHomLHHa “Have saw: mgommuco mucnumHmmc comm :H mca>Hszu came we wmmpcmugwm mann mme Langmcu swam WHO Hp ma poo;m .axw HHmz .HmH m w m NI m w m N H m _N H m w m N H m w m NI c3, mm.Hm u Nx m.— «t.» HNéOHw n cmggwwwga >L¢> um uwgcmdmga ”v .mmga HHmuchwscmch um oo. o u .wwgauco: szHmevoz uN xx mo.¢m n x 00.0 Nx Nx vaccmewcaucoz ”H N .m mgzde oH ON d a J cm a U a. p. S w 0 I: om o m. 1. co M. p. J E s ow om ooH 61 class. Non-preferred and very preferred classes had a fairly similar percentage of cultivars with adult attraction of 40 and 43%, respect- ively. The highest proportion of cultivars showing adult attraction to petioles was in the non-preferred class (i 8 %). But, the lowest percentage was in the moderately non-preferred class (20%). Inter- mediately preferred and very preferred classes were fairly similar in percentages of cultivars with petiole adult attraction (3l and 33, respectively), while the proportion of cultivars in the preferred class was somewhat intermediate (50%). Cultivars with adult attraction to the stem were recorded only in the moderately non-preferred and in the intermediately preferred classes (l0 and 11%). The x2 values calculated for each leaf and for the chamber indicated that only the shoot, the petiole, and the stem ex- hibited in general significantly different mean adult attraction values between the classes of resistance (Figure 9). The mean percentage of adults in each leaf-part and in the chamber for the five groups of cultivars are reported in Tables 2l through 24. The first well expanded leaf blade and the shoot in the non-pre- ferred and moderately non-preferred groups, were the least attractive to the whitefly adult. Intermediately preferred groups of cultivars were less stable in their response under the greater insect pressure. Such variation in place with the observed values in the free-choice screening experiment was likely due in part to the narrowed choice for host site selection by the adult. 62 In the non-preferred class (Table 21), it is shown that genera other than Phaseolus and species other than Eh. vulgaris were again least attractive to the whitefly adult. Leading the leaf blade non- preferred category was Dolichos lablab (5.5%) followed by Vigna repens (l2%). In decreasing order of non-preference, but still with consider— able adult non-preference, were Eh. lunatus GOll54 with 24% and Eh, coccineus 000046 with 27%. Vigna radiata 000l28, Eh, coccineus 000038, and Eh, lunatus GOOl27 were lower in adult non-preference response than in the screening experiment. Their leaf blades attracted only about one—half of the infested number of adults (42, 43, and 57%, respect- ively). The reduction of adult attraction in the most resistant culti- vars was also probably due to the reduced opportunity of the adult for plant site selection. In the moderately non—preferred class (Table 22), nearly all culti- vars (about 70%), fairly well filled their class. In this adult attraction category, and mainly in the Eh. vulgaris group, adult attraction was associated with almost no attractiveness to the shoot and by a fairly low percentage of attraction to the first well expanded leaf blade. Exceptions in this group were PI 309-804, 803097, and 002980, whose shoot attraction values were 5.56, 8.47 and 23.8l%, respectively. A Eh, vulgaris 004485, was apparently the only cultivar in the moderately non-preferred category that was outstandingly more attract- ive under confining conditions. Lowest adult attraction for the leaf blade was exhibited by the Eh. vulgaris cultivar 602980 (28%), but this low attraction seemed to be associated with a fairly similar attract- iveness shown by the shoot (2 %). Following this cultivar in ascending 63 .:oH55NHLommuco acmngmgxm acwcmmgom 05H OH mcHuLouoc umHLOm mL5>HHH5u + 5.: 85 8.: 85 8.: Ag may 8:8 W8 85 2.: 85 85 H8|EMH 35 858 N55 85 :5 :5 8.8 H3 .eln: 888 5.8 85 85 85 2.8 Hag :5 888 8.8 85 85 85 8.3 Hg: .J 358 5.8 55.5 85 85 8.8 Hg $911: 858 58 85 5:: 85 8.2 183395 R88 8825 88 25:8 585 825-23 + 2§E8 mccwcwogwm .cowuoagpum szum Lo+ mmaHo smegmdmgqnco: 55H $0 mL5>Hquo :H HHmz Lmnsmgu 8:5 HemauemmH 5555 so mezum do mmmucwocma .HN mHnmp 64 .cowpmNHLommpmo pcwawgmaxm mchmeom asp ou acwugouom vaLOm 5L8 8555: 55>H5Hsu + N55 85 85 85 8.8 7:; 5.: 8.535.; 5:28 5.8 85 85 $5 8.8 $498?» .flv 888 8.: 85 85 5.8 8.8 Hg .flv 888 :8 85 8.8 85: 8.8 Ham 5.5.5 8:8 :8 85 85 85 8.8 Ag .flv 888 m5 85 85 85 E55 Hg .55 838 5.: 5:5: 85 85 8...: A; .flv :52 5:285 N55 85 85 8.8 8.8 Hg 5.5 58-58 E 5.5 85 85 85 85: Ag .55 888 m5: 85 :5 85 8.2 A3 .91: 8:58 8825 88 25.5.8 858 882.83 22.58 0&6».chme J_. .coHuomcupa HHsum Low mmmHo umgcmwmga-:o: szuccwvoE ms» do mLm>Hquu CH HH53 Lansmzo 5:5 HL55-$55H some :H co mHszm we monucwocmm .NN anmH 65 order of attractiveness were: Eh, accutifolius GOl222 and Eh: vulgaris entry 000787 both with 40% leaf—blade adult attraction. However, Eh. accutifolius registered lO% of adult attraction compared with the zero attraction value registered for the 800787 shoot. A good deal of non- preference to the leaf-blade was also recorded for Eh, vulgaris entry PI-309-804 and G03097 (52 and 5 % of adult attraction). Plant phenotypic differences, such as intrinsic differences in color, light refraction, number of stomata, and hardness of the leaf cuticule, as well as some chemical factors, such as differences in precursors of tanins and/or pigments later determining the seed coat color, might be conferring the observed resistance in some of the culti- vars in these two groups of cultivars previously referred. Intermediately preferred cultivars (Table 23) in general exhibited higher leaf blade adult attraction but fairly similar shoot attraction than the moderately non-preferred group. Table 24 shows the mean percentage values of adults in each treat- ment by each cultivar in the preferred and very preferred classes of adult attraction. No really distinctive differences in leaf blade adult attraction were observed between cultivars in the most preferred categories com- pared with those of the intermediately preferred class. But a distinct- ly greater single shoot attractiveness and a greater proportion of cultivars having shoot adult attractiveness was generally observed, thus suggesting that susceptibility in these groups of cultivars might be associated with the greater preference of the shoot. This shows that whitefly non-preference in bean cultivars, and mainly in the Eh. vulgaris group, depends more on the non-preference 66 .55555N55505555 55555555x5 055555555 555 55 055555555 555555 555 55555 555>55H55 5555mH5> mam + 05.m 05.0H 0w.mH 05.mH 00.0H 00.05 00.0N 0.0N m.H5 5555550 00.0 00.0 50.0 00.0 00.0 00.0 00.0 00.0 00.0 5555 :5.5: 55.5 55.5 :5.5 55.5 55.5 55.5 55.5 55.5 55.5 55.5 55.5 55.5 55.5 55.:: 55.5 55.5 55.5: 5:5:555 55555 55.:5 55:,5-5: 55.55 555555 55.55 555-55:-:5 55.55 55:555 55.55 :55-<5: 55.55 5-552 55.55 H550 :55 55.55 «WHummHm» ammv :55555 55.55 HmHmmmHm» 5550 55-55: 555:5-5555 55>:5:55 + 5555555550 :55: ll .5555555555 5:555 505 555:5 555555555 5:555555555555 5:5 55 555>55H35 :5 HH53 5555555 555 5555-555H 5555 so 55:555 55 5055555555 .MN 5H55H 67 Table 24. Percentage values of adults on each leaf-part and chamber wall in cultivars of the preferred and the very preferred class for adult attraction. Mean percentage Cultivar + Leaf-blade Shoot Petiole Stem Chamber Preferred: 15R-287 57.41 0.00 3.70 0.00 29.00 Calima 67.26 18.45 4.76 0.00 9.50 003037 80.82 0.00 0.00 0.00 19.80 003159 67.86 9.52 4.17 0.00 18.40 001225-N 74.60 10.32 0.00 0.00 15.10 001225-S 80.42 0.00 0.00 0.00 19.60 Verz preferred: 003042 68.89 5.56 0.00 0.00 18.80 003167 48.61 25.00 4.17 0.00 22.20 1-59 77.25 9.53 0.00 0.00 3.20 001204 49.80 9.52 8.33 0.00 32.30 001083 70.79 18.89 0.00 0.00 10.30 000718 82.14 4.76 0.00 0.00 13.10 + Eh, vulgaris cultivars names are sorted according to the screening experiment categorization. 68 responses of the shoot, though in the least preferred groups of cultivars, non-preference of well expanded leaflets in the upper part of the plant is certainly more important. Petiole attractiveness exhibited by the two, or perhaps three, most adult preferred classes might be attributable to changes in leaf turgidity and perhaps to other unknown physiological processes also changing at greater extent in the leaf blade of these particular groups of cultivars. Since the petiole and stem, under natural conditions, have been observed by the author to be plant parts not commonly selected by the whitefly adult, and considering the fact that adult attraction by these parts was recorded mainly in the most non—preferred cultivars, it is believed that this kind of adult attraction was merely a kind of escape alternative whitefly adults used in perhaps looking for a place showing a less repellent effect, or a place better supplied with sap, or both. The number of adults recorded on the chamber wall of the most preferred cultivars are attributed to: (l) the intrinsic and natural searching of any animal in a foreign ”habitat", and (2) short flights, especially in the more susceptible cultivars (perhaps as part of the whitefly adult normal behavior). This probably predisposed some of the adults to rest on the chamber wall. The greater number of adults on the chamber wall of the most resist- ant categories of cultivars might be due either to the presence of a repellent effect from the cultivar or to a strong attraction exhibited by some more preferred neighboring cultivars, or both. 69 Factors strongly suggesting the presence of mechanisms which were either physically or chemically repelling to a greater extent in the non-preferred and in the moderately non-preferred groups of cultivars, or at least in some of them, are the following: (l) these groups had the lowest leaf blade adult attraction values of 5.5 and 40%, respect- ively, (2) the petioles received significantly higher attraction (3l and 33%, respectively), (3) these groups had a higher percentage of cultivars with less than 6% of adult attraction (59 and 29% of the cultivars had zero and less than six percent attraction, respectively). Additional support for these hypotheses is that such whitefly ”repelling” responses were more distinctive in the most non-preferred cultivars. Moreover, most of the preferred cultivars, though they exhibited adult attraction toward almost every leaf part, attracted adults mainly to the leaf blade and to the shoot. These are the most often selected plant parts in the field, perhaps because they are more succulent and better supplied with sap. Correlation coefficients between the whitefly adult attraction values in each cultivar in the screening experiment and the corres- ponding mean values of varieties and leaf—blades in the adult leaf preference experiment are reported in Table 25. No significant corre- lation was found for any single resistant class compared. However, highly significant correlation was found for both mean variety values and mean leaf-blade values when comparing the 38 cultivars in the five resistant classes studied. The magnitude of the calculated r-values for each class suggests that the most consistent response was found in the non-preferred and 70 Table 25. Correlation coefficients between the adult attraction values observed in each cultivar in the screening experiment and corresponding mean varieties and leaf- blades in the adult leaf preference experiment. Group correlated Non-preferred: Screening exp. vs. adult pref. adult pref. Moderately non-preferred: Screening exp. vs. adult pref. adult pref. Intermediately preferred: Screening exp. vs. adult pref. adult pref. Preferred: Screening exp. vs. adult pref. adult pref. Very preferred: Screening exp. vs. adult pref. adult pref. variety variety- variety variety variety variety variety variety variety variety value blade value leaf-blade value leaf-blade value leaf-blade value leaf-blade Screening exp. vs. adult pref. experiment var. value adult pref. variet leaf-blade ** Significant at P= 0.01 .59 .65 .19 .26 .05 .26 .38 .30 .47 .82 .54 ** .43 ** 71 very preferred cultivars (r=0.59 and r=0.47) selected in the screening experiment. These higher values were probably beside the number of varieties compared, with the greater contribution afforded to the high significance level (P=0.0l) obtained in the correlation coefficient between adult attraction values of both experiments. Groups classified intermediate in their attractiveness in the screening test were more erratic in their responses in the chamber test. Again phenotypic considerations of the nature previously mentioned supported mainly in genotypic differences than in environmental contri- butions might be the main factors involved to show such responses. SUMMARY AND CONCLUSIONS Breeding bean plants for genetic resistance to either the greenhouse whitefly (I, vaporarium Nest.), or to the tropical bean whitefly (E. tabaci Gen.), provides an ideal way of controlling physical damage, and can greatly reduce the frequency of bean plants with virus diseases. Thus, this research evaluated ll8 bean cultivars of four species of Phaseolus, two species of Eighh, and one of Dolichos (all Leguminosae members), for shelter and oviposition in free-choice greenhouse conditions, and studied leaf part preferences exhibited by adult whiteflies confined to 38 selected cultivars of the three genera with varying degrees of resistance. The highest level of adult-shelter and oviposition non-preference was found in genera other than Phaseolus. Within the genus Phaseolus, attractiveness to the whitefly was also lower in species different than Eh, vulgaris. The adult non-preferred class for shelter consisted of the two Vigna repens and v, radiata, the two Eh, lunatus 600l27 and GOll54, and two Eh. coccineus 600046 and 600038. In the moderately non-preferred class there were eleven Eh. vulgaris cultivars and Eh, accutifolius. Three Eh. vulgaris, a wild and black seeded type 600132, 603645, and PI 309-804, both black seeded cultivars, were the least preferred in this resistance class. 72 73 604487 black seeded, 600787 red seeded, and 603244 black seeded, in descending order of preference, were less adult preferred for shelter than the Eh. accutifolius 601222. Probably the wild types of Eh, vulgaris and among them, the black types, are the best sources in this species to search for higher levels of whitefly adult non-preference. One of the cultivars leading the adult shelter preferred class was a very susceptible leafhopper Eh, vulgaris cultivar, 1-59 which is a light brown seeded type. The four Eh. vulgaris following it in ascending order of preference were 604525, 703 (black), Rayada (striped), and 60l225 (striped). The presence of Eh. coccineus 600039 in this class, compared with the presence of the other two Eh. coccineus (600046, and 600038), in the non-preferred class shows the broad genetic variability in this species for whitefly adult attraction. The six Eh, vulgaris very preferred for adult attraction, in decreasing order of preference were: 600718(striped seeded), 603101 (black), 604494 (striped), 601054 (dark red), 601083 (striped), and 601204 (white). In the non-preferred class for oviposition, 11322.E§2§fl§.G00037 and V. radiata 600128, Eh, lunatus 601154 and 600127, and the Dolichos lablab were the least preferred. Also, in this class were both Eh. coccineus 600046 and 600038, which had oviposition readings of 1.3 and 1.8 compared with the oviposition reading of 1.0 in the previously mentioned entries. 74 Only four Eh, vulgaris cultivars, 600129, 600787, 603244 (black seeded types), 600787 (red seeded type), and the Eh. accutifolius, 601222 (white seeded), were in the moderately non-preferred category for whitefly oviposition. In the preferred class for oivposition, two striped cultivars 601225 and 600718, a white seeded 600808, and two black seeded 603115 and 603167, in ascending order of preference, exhibited the highest attraction. The most preferred cultivars in the very preferred class in ascending order of attractiveness were: l-59, brown seeded; Rayada and 602997, both black seeded; and 601204, a white seeded cultivar which was also very adult preferred for shelter. The presence of the Eh. vulgaris cultivar, 1-59, a very suscept- ible leafhopper cultivar in the adult preferred class, and the presence of this cultivar in the very-preferred class for whitefly oviposition suggests that in the Eh, vulgaris group the same factors for leafhopper and whitefly susceptibility might be involved. In the Eh, vulgaris species, striped and brown seeded varieties were the most preferred for whitefly shelter and for oviposition. Some black seeded types, followed by red ones and some white ones, were the least attractive for whitefly shelter and oviposition. In confined conditions, only two groups of cultivars were dis- criminated with Tukey's hsd—values when plant parts were separately analyzed for adult attraction. It allowed identification of cultivars exhibiting non-preference even under greater infesting pressure which is an instance of Painter's two types of non-preference distinctions (40). 75 Adult preference for the leaf blade of the first well expanded leaflet was statistically different. Attraction values of the shoot, the petiole and the stem were 18, 16 and 2 percent, respectively, of the attraction value of the first well expanded leaf blade. In all groups of resistance, significant association was found between the variety adult attraction values and the first well expanded leaf blade attraction values. Although not always significant, negative correlation between leaf blade adult attraction versus shoot, petiole, and chamber effect was nearly always found (70%). A highly negative association between leaf blade adult attraction and the number of whitefly adults in the chamber was found for the non-preferred, the moderately non-preferred, and the intermediately preferred. Significant negative association, but only at P=0.05 level, was found for the group of the two highest preferred classes. Therefore, in the Eh, vulgaris group there was a tendency for cultivars in the most preferred classes to show greater adult attraction to leaves and less adult attraction on the chamber than in those cultivars in the non-preferred group. Almost no correlation between leaf blade adult attraction with shoot adult attraction was found in the non-preferred class. The lowest mean adult attraction value in the first well expanded leaf blade was in the non-preferred class (30%), followed by the moderately non- preferred class (61%), the very preferred class (66%), the intermedi- ately preferred class (69%), and the preferred class with about 71%. Lowest shoot adult attraction was in the non-preferred and the intermediately preferred classes (1.75 and 2.7 %, respectively). This attractiveness was highest in the most preferred classes. 76 The lowest petiole attractiveness was observed in the most preferred classes, but highest attractiveness was observed in the non- preferred class. Stem-adult attraction was recorded only in the moderately non— preferred and the intermediately preferred cultivars (with 1.3 and 0.41 percent, respectively). The highest proportion of cultivars showing shoot adult attraction was recorded in the very preferred and preferred classes with 100 and 50%, respectively. The highest proportion of cultivars showing petiole adult attraction was recorded in the non-preferred class with 86%. Only 10 and 11% of the moderately non-preferred and the intermediately pre— ferred classes, respectively, showed stem—adult attraction. Leading the first well expanded leaf blade non-preferred category was Dolichos lablab, with 5.5 percent of the adults attracted. This was followed by Vigna repens with l %, Eh, lunatus 601154 with 2 %, Eh, coccineus 600046 with 27%, V. radiata with 42%, Eh. coccineus 600038 with 43%, and Eh. lunatus 600127 with 57%. In the moderately non-preferred category, lowest adult attraction to the first well expanded leaf blade was Eh. vulgaris 602980 with 2 %. However this low attraction was associated with a fairly similar attract- iveness exhibited by the shoot (24%). Following this cultivar in ascending order of attractiveness were: ‘Eh. accutifolius 601222 and Eh. vulgaris 600787 each having 40% leaf blade adult attraction. However, the shoot of Eh. accutifolius had 10 times greater adult attraction than 600787 (10% vs. 0%). 77 Higher cultivar-shoot attractiveness and a higher proportion of cultivars showing shoot-adult attraction was recorded in the two most preferred classes. Thus, susceptibility seemed to be associated in part with the preference shown for the shoot. Petiole attractiveness in the two or three most preferred classes was considered to be an escape alternative that whiteflies used in searching for more succulent plant tissue. Among other unknown physiological changes, perhaps substantial changes in the leaf turg- idity caused by excision of the leaves in this particular group of cultivars was the main factor involved. The greater number of adults on the chamber wall (56% and 29%) was recorded in the non-preferred and the moderately non-preferred classes. The significant higher attraction of the petiole of these classes (31 and 33%), the higher percentage of cultivars with less than % of adult attraction (88% of the cultivars), and the lowest leaf blade adult attraction values (5.5 and 40%, respectively), suggests that these two groups of cultivars, or at least some of them, have mechanisms which either physically, chemically, or both, were repelling the whitefly to a greater extent. Hhitefly non-preference in all bean cultivars, but more in the Eh. vulgaris group, depended on very low attractiveness of the shoot, although non-preference for the well expanded leaflet at the upper part of the plant was shown in the least preferred cultivars to be a more desirable characteristic. 10. REFERENCES Alonzo-Padilla, F. R. 1976. Reporte anual. del Proyecto de Entomologia en Frijol. In the: Reporte anual del Programa de Produccion del Frijol 1975-76. Inst. de Ciencia y Tec. Agric. 6uat. C. A. 12-40 p. , 1971. Insect-pest Management and Control. Principles of plant and animal pest control, Volume 3. Nat. Ac. Sci. Ed. Office. Nat. Ac. Sci. 508 pp. Amaya, V. R. 1973. Influencia de colores en la atraccion de la mosca blanca Bemisia tabaci (6enn.) en frijol comun. XIX Rev. PCCMCA Costa Rica. Applebaum, S. M., S. Marco, and Y. Birck, 1969. Saponins as possible factors of resistance of legume seeds to the attack of insects. Agric. Food Chem. 17:618-22. Applebaum, S. 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F. 1971. The Insects Structure and Function. Elsevier, NY. 819 pp. Curry, J. P., and D. Pimentel. 1971. Life cycles of the green~ house whitefly, Trialeurodes vaporarium, and population trends of the whitefly and its parasite, Encarsia formosa, on two tomato varieties. Ann. Entomol. Soc. Amer. 64:1188-1190. Dethier, V. 6. 1954. Evolution of feeding preferences in phytophagous insects. Evolution 8:33—54. Duffes, J. E. 1965. Beet pseudo-yellows virus transmitted by the greenhouse whitefly (Trialeurodes vaporarium). Phytopath. 55:450-453. _ Fischer, S. J. and J. B. Shank. 1974. Host preference of the greenhouse whitefly: Effect of poinsettia cultivars. Amer. Soc. Hort. Sci. 99:260—262. Fraenkel, 6. 1959. The chemistry of host-specificity of Phytophagous insects. Proc. 4th Int. Congr. Biochem., Vienna 1958. 12:1-14. Friend, H. 6. 1958. Nutritional requirements of phytophagous insects. Ann. Rev. Entomol. 3:57-74. Gentile, A. 6., R. E. Webb, and A. K. Stoner. 1968. 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H., N. J. Parr and B. 6urney. 1958. The effect of whitefly population on the cropping of tomatoes. Rep. Glasshouse Crops Res. Inst. 79-86 pp. Klingauf, F. 1971. Die vierkung desglucosides phlorizin auf das wirts wahlverhalten von Rhopa Ropalosi hum insertun (Nalk.) und Aphis poni. De 6eer. (Homoptera: Aphididae). Z. Angew. Ent. 68:41-55. In: Shonhoven, L. M. (ed.). 1972. Some aspects of host selection and feeding in phytophagous insects. Ins. and Mite Nut. North Hol., Ams. 557-565 pp. Light, E. N. (No year). Half strength modified hoagland solution. Earhart lab. MSU. E. Lansing, Mich. l p. Lloyd, L. L. 1921. Notes on a colour tropism of Asterchiton (Aleurodes) vaporariorum Hestwood. Bull. Entomol. Res. 12:355-359. Lloyd, L. L. 1922. The control of the greenhouse whitefly (Asterochiton vaporariorum), with notes on its biology. Ann. Appl. Biol. 9:1-32. Cipke, H. and 6. Fraenkel. 1956. Insect nutrition. Ann. Rev. Entomol. 1 17-44. Macdowall, F. D. H. 1972. Phototactic action spectrum for white- fly and the question of colour vision. Can. Entomol. 104:299-307. Maltais, J. B. and Auclair, J. L. 1957. Factors in resistance of peas to the pea aphid, Acyrthosiphon pisum (Harr.) (Homoptera: Aphididae). I. The sugarznitrogen ratio. Can. Entomol. 89:365-370. Matsumoto, 1960. Studies on the host plant determination of the leaf-feeding insects, V. Attraction of leaf alcohol and some aliphatic alcohols to the adult and larvae of the vegetable weevil. Ber. Ohara Inst. Landwirtsch. Biol. 11 359-64. Maxwell, F. 6. 1972. Host plant resistance to insects. Nutri- tional and pest management relationships. In: Rodriguez, J. 6. Insect and Mite Nutrition. N. Hol., Ams. 599-610. Morril and Back. 1911. Nhiteflies injurious to citrus in Florida Bul. 92. Bur. Entomol. U. S. Dept. Agric. (In Lloyd, 1922). 37. 38. 39. 40. 41. 42. 43. 44. 45. 51. 81 Mound, L. A. and S. H. Halsey. 1978. Whitefly of the World. John Wiley and Sons. 340 pp. Newton, R. C. and D. K. Barnes. 1965. Factors affecting resistance of selected alfalfa clones to the potato leaf- hopper. J. Econ. Entomol. 58(3)2435-439. Painter, R. H. 1941. The economic value and the biologic signi- ficance of insect resistance in plants. J. Econ. Entomol. 34:348—57. Painter, R. H. 1951. Insect Resistance in Crop Plants. McMillan. NY. 520 pp. Painter, R. H. 1969. Plant and animal resistance to insects. Ann. Rev. Entomol. 3:267-290. Perkins, J. 1908. The leguminosae of Puerto Rico. In: Contributions from the United States National Herbarium. Vol. X Nash. 60v. Print. off. 494 pp. Pillemer, E. H. and w. M. Tingey. 1976. Hooked trichomes: A physical plant barrier to a major agricultural pest. Science 193. (4252):482-84. Rock, J. F. 1920. The leguminous plants of Hawaii. Exp. Sta. Hawaiian Sug. Plant. Assoc. 226 pp. Russel, L. M. 1963. Host and distribution of five species of Trialeurodes (Homoptera: Aleyrodidae). Ann. Entomol. Soc. Amer. 56:149-153. Snelling, R. 0. 1941. Resistance of plants to insects attack. Bot. Rev. 7:543—586. Speyer, E. A. 1929. The greenhouse whitefly (Trialeurodes vaporarium (Westw.)). J. Roy. Hort. Soc. 54:181-192. Steel, R. 6. D. and J. H. Torrie. 1960. Principles and Pro- cedures of Statistics. McGraw-Hill Book Co. Inc. 481 pp. Swiff, L. 1974. Botanical Classifications. The Shoe Spring Press, Inc. 367 pp. Ting, S. V. 1956. Rapid colorimetric methods for simultaneous determination of total reducing sugars and fructose in citrus juices. Agriculture & Food Chemistry. 4(3):263-16. Threhan, K. M. 1940. Effect of coloured screens on oviposition and the development of some British whiteflies. Ind. Entomol. 3(1):121-l37. 53. 54. 55. 82 Trasversi, B. A. 1949. Estudio inicial sobre una enfermedad del girasol (Helianthus annus L.) en Argentina. Rev. Invest. Agr. Buenos Aires. 3:345-351. Varma, P. M. 1963. Transmission of plant viruses by whiteflies. Ind. Agric. Ress. Inst. Plant. Virus. Ress. Labo Pooma. 5:10-33. Holfenbarger, D. and J. P. Sleesman Ag. 1961. Plant character- istics of Phaseolus vulgaris associated with potato leaf- hopper nymphal infestation. J. Econ. Entomol. 54(4):705-707. Nolfenbarger, 0. and J. P. Sleesman Dec. 1961. Resistance to the potato leafhopper in lima beans lines, inter-specific Phaseolus crosses, Phaseolus spp., the cowpea and the bona- vist bean. J. Econ. Entomol. 54(6):1077~1079. APPENDIX Free-choice Greenhouse Bean Adult Preference. Table 1. Sorted transformed means ( No. of adults attracted ) per cultivar given by the computer in the ANOVA, (hsd= 2.3326). Cultivar Mean Seed coat color 600037 (V igna repens) 1.1630 Brown 600128 (Vi na radiata) 1.7743 Green 600127 (Phaseolus lunatus) 1.8068 White 600046 (Phaseolus coccineus) 2.1125 Redish Brown 600038 (h . coccineus 2.3863 Redish Brown H00126 (Dolichos lablab) 2.4673 Cream 601154 (P . 1unatus1 2.7345 White 600132 (Phaseolus vul aris, Wild) 3.6675 Black 603645 (Jamapa-se1.11PPh. vulgaris) 4.3592 Black PI-309.804 (Eh, vu1aniS) 4.3944 Black Porrillo No. 1 (Eh, vulgaris) 4.9063 Black 604485 (Ph.vulgaris1 5.1513 Black 604487 (Eh.v vulgaris) 5.1817 Black 600787 (Eh,vu19aris) 5.2066 Red 603244 (Eh. vulgaris) 5.5386 Black 601222 (Eh. accutifolius) 5.5637 White 602980 €Eh.v vu1 aris) 5.6121 Black 603097 Ph vu1 aris) 5.7355 White Porrillo-Si” ntetico 1Wvu1gariss) 5.7597 Black Pinto- 114 vul aris) 5.9402 Striped 15R-52 (h %ul aris1 6.0160 Black 600129 (PF'N u1 aris) 6.2755 Black 604481 (P—.V u1a 5) 6.3131 Black 602983 (W vul aris) 6.4460 Black Brazil- 2_(Ph+ vul aris) 6.4681 Brown 602977 rPh vu1 aris 6.5490 Black Venezuela- h2 1Ph. vul aris) 6.5916 Black 603108( vulgaris1 6.2028 Black S- 116- A- N :(Ph vul aris) 6.6701 Black 602960( vulgaris 6.7083 Black 584( F4) ((Ph. vul aris) (MSU-record) 6.7144 Black 600805 (Ph.vulgaris1 6.7483 Red 651051 (Ph. vulgaris) 6.7505 Black Nep-2 (Ph vulgaris 6.7581 White 601205 1Ph. vul aris) 6.7997 Striped ICA- Tui (Ph. vu1 aris) 6.8089 Black Colorada del pais 1Ph vulgaris) 6.8564 Striped 603164 (Eh_.v vulgaris) 7.0622 Black 83 Cont. Cultivar 603064 (Ph Puedo (Ph. appendix, Table 1. __. vul aris) aim, PompadoUELZ Ph 604298 (EE- Pinto (Ph. 1 84 . ul aris) VET-aris1 vulgaris 600133 (Negro Palencia) (Ph. vulgaris) 600808 (Ph. Sanilac (Eh. Charleriox Ex—Rico 23 (P6. Mexico—309 000773 (Eh. 003211 (Ph. 15R-l94 (Eh 603248 (357 71-IR-101 (Ph __, vul aris) vul aris 603008 (P 603059 ( 603215 ( 603027 (P 604489 (P 603195 (Ph. 1203 (Ph vulgaris) vulgaris) (Ph. vulgaris) vulgaris) (Eh. vul aris) vulgaris) vulgaris) . vul aris) vulgaris) 1 vul aris s) vul aris) vulgaris) S) ) 11, 11 aris vulgaris T_yul aris1 603213-1Lh. vuigaris) ICA- Pijao _(Lh. 15R- 287 (Lh. 601224 (Eh. Black Turtle 602988 (Lh. Calima (Eh,v 603236 (Eh.v 603229 (Eh, 603235 (Eh, 603132 (Eh,v 603165 (Eh.v 600822 (Lh 600130 (— 603037 (Ph. PorrilloZMex. 603233( 603109 ( 603013 ( 603184 ( 602994 (PF: 603012 ( 603126 ( 600039 ( V 1 vul aris) vul aris) ul aris1 Ph vul aris) ul—aris 1 1 vul aris vul aris S) ) vul aris s) S) ) ) 1113 vul aris vul aris vul aris 1111 . vul aris) Negro Parramos) )(Lh.v vulgaris) vul aris) .vulgaris) vu1_ aris . vulgaris mmoxoxo00000000000000ooooooooooooooooooooooooooooooooooooxnwwwuuuwuxnwwwuww Mean .0710 .2279 .2367 .4363 .4368 .4500 .5166 .6469 .6596 .6700 .6863 .7129 .8650 .9255 .9566 .9665 00356 .0524 .0609 .0665 .1307 .1584 .1651 .1777 .1825 .2389 .3418 .3675 .3906 .4914 .5207 .5246 .5532 .6012 .6129 .6332 .6639 .7006 .8721 .9342 .0828 .1481 .2653 .3295 .3646 .3699 .5107 Seed coat color Black Black Striped Red Striped Black White White Red White Black White Black Brown Black Dark Purple Black Black Black Black Black Black Creamish-orange Black Black Brown Brown Black Black Striped Black Black Black Black Black Brown Black Black Black Black Black Black Black Black Black Black Redish Brown 85 Cont. appendix, Table 1. Cultivar Mean Seed coat color 602963 (Eh. vulgaris) 9.5135 B1ack 603159 (Ph. vul aris) 9.5563 Black 602987 (PF: vulqaris) 9.6307 B1ack 600131 (E. vulgaris) 9.6689 Black 2-1029 (L1. vulgaris) 9.7465 Black 603024 (Ph. vu1 aris) 9.7645 Black S-630-B-6T63 (Ph. vul aris) 9.8624 Brown 605706 (E. vu1—garis1 9.9177 Black 602997 (31. vulgaris) 9,9206 Black Sw.Br. (_Ph. vulgaris) 9.9942 Brown Puebla-52 (Eh. vul ar1s) 10.1234 Brown 603115 (Ph. vulgaris1 10.1805 Black 703 (Eh._Vulgaris 10.3253 Black Rayada (Lh. vulgaris) 10.4426 Striped 601225 (L. uvlgaris) 10.4912 Striped 60 3145 (Eh. vulgaris) 10.6645 Black 603099 (Lh . vulgaris) 10.7254 Black 601051 (E. vulgaris) 10.9868 Striped Red Kidney (fl. vul aris) 11.0708 Red 603178 (a. vulgaris) 11.1557 Brown 603042 (E. vulaaris) 11.1699 Black 603167 (_. uvlgaris) 11.1878 Black 603245 (P_h. vulgaris) 11.2102 Black 603252 (_.v uvlgaris) 11.2122 Red 603645 (Lh. vu1 aris) 11.2885 B1ack 1- 59 (Ph vulgaris 51 11.6318 Brown 6045257'P_h.v vulgaris) 11.7655 Black 601204 (E_. vulgaris) 12.2315 White 601083 (_h. vulgaris) 12.4303 Striped 601054 (P_h. vulgaris) 12.5316 Red 604494 (P_h. vulgaris) 12.5575 Striped 603101 (Eh. vulgaris) 13.2147 Black 600718 (Lh. vu1garis) 14.2484 Str1ped 86 Cont. appendix. Table 2. Sorted means of readings of oviposition preference (1 through 5) per cultivar given by the computer in the ANOVA, (hsd= 0.7668). Cultivar Sorted means 601154 (P lunatus) 1.0000 H00125 E061ic c505 1a b1ab) 1.0000 600037V1gnarepens 1.0000 600128 (V igna radiata) 1.0000 600127 (Eh. atus11un 1.0000 600046 (Eh. coccineus) 1.1333 600038 (Ph . coccineus) 1.1667 600129 (E:. vulgaris1 2.0000 600132 (Eh, vulgaris, Wild) 2.1333 601222 (Eh, accutifolius) 2.1667 600787 (Eh, vulgaris1 2.5000 603244 ELh,V vu1garis) 2.5000 15R-52 Ph.vu1 aris) 2.5333 Pinto( vul aris1 2.5667 Porrillo-PWex.1Ph.vu1 aris) 2.6333 600773( .vul aris1 2.7000 P1. 309. 804 (h vu1 aris) 2.7000 603645 (Jamapa- -se Eh. vulgaris) 2.7333 Sanilac (Eh. vul aris) 2.8000 Black Turtle (Lh. vul aris) 2.8333 Porrillo Sintetico 1Ph. vulgaris) 2.8333 605706 (Lh. vu1 arisj—_ 2.9000 602980( vul aris) 2.9000 PorrilloP No. 1 1Lh. vul aris) 2.9000 Pompadour- 2( vul aris 2.9333 602977 (Lh.vUThar1s1 2.9667 ICA- Pijao —(Lh. vul aris) 3.0000 600133 (Negro Palencia1 (Eh, vulgaris) 3.0000 602983 (Eh, vu1 aris) 3.0000 600130-Parramos 1Eh. vulgaris) 3.0000 Sw.Br. (Eh, vul aris) 3.1000 Puedo (Ph. vulgaris1 3.1000 603097 (Lh. vu1garis) ) 3.1000 600131- Chimaltenan o (P vulgaris 3.1333 Puebla- 52 (Lh. vulgari57' 3.1333 602960 (Ph. vu1garis s1 3.2000 ICA- Tui ((Ph. vul aris) 3.2333 603132 (Ehj'vulgar1s1 3.2333 603012 (Ph. vulgaris) ) 3.2667 Venezuela-2 (Ph. vul aris 3.3333 600822 (Eh, vUTharis1 3.3333 Cont. appendix, Tab1e 2. Cu1tivar Mexico-309 (Ph. vu1 aris) 602963 (P_h. W1ga+ris 602994 (Ph. vu1garis) 581(F4) (P'. vu1garis) Ex-Rico 23_(Ph. vu1 aris) 604525 (Eh, V61 arisi 703 (Ph. vu1garis 1 603213—(Eh, vu1garis) 603236 (Eh, vu1garis) 602988 (Ph. vu1garisg 603064 (Ph: vu1 aris 51051 (PET vu aris 603211 (Eh. vu1 aris) Coiorada de1 pais 604485 (Ph. vu1gari§7 Brazi1-271Eh, vu1 aris) 603159 Eh, vu1.ari51 111 603101 (Ph 1 ' ) . vu aris 600805 (Eh. vulgaris) 603108 (Eh, vu1garis) Ca1ima (Eh. vu1qaris) 603109 (Eh, vu1garis) 603229 (Eh, vu1garis) 603184 (Eh, vu1garis) 603059 (Eh.(vu1garis) ) Red Kidney Ph. vu1 aris 601205 (Eh, V61garisi 603233 (Ph. vu1garis) 15R-194 (Eh: vu1 aris) 604481 (Eh° vu1garis§ 603013 (Eh. vu1garis) 603164 (Eh. vu1garis) 601224 (Ph. vuigaris) 71-IR-101_(Ph. vu1 aris) 603248 (Eh,_Vhiqari51 S-630-B-C-63 1Eh. vu1gar15) 603037 (Eh. vu1garis) 603136 (Ph. vu1 aris) 39332411136-4—1” a1? 1 in o- . vu aris Char1eriox (Eh. vu aris) 15R-287 (Eh, vu1 aris 601054 (Ph. vu1 aris1 S-116-A-N_(Eh. vul aris) 603215 (Eh, vu1 arisi 604489 (Eh. vu1garis) 603195 (Eh. vu1garis) 1 Ph. vulgaris ) 87 Sorted means .3333 .3667 .3667 .3667 .3667 .4000 .4333 .4333 .4333 .4667 .5000 .5000 .5000 .5000 .5000 .5333 .5333 .5667 .5667 .5667 .6000 .6333 .6333 .6333 .6333 .6333 .6333 .6333 .6667 .6667 .6667 .7000 .7333 .7667 .7667 .7667 .7667 .7667 .7667 .8000 .8000 .8000 .8333 .8333 .8333 .9000 .9000 wwwwwwwwmwwwwwwwwwwwwwwmwwwwwwwwwwwwwmwmwwwwwww 88 Cont. appendix, Tab1e 2. Cu1tivar Sorted means 2-1029 (Ph. vu1 aris) 4.0000 1203 (Ph. —vu1qarisi 4.0000 Nep-2 (Ph. vu1garis) 4.0000 603645 @1- vu1oaris) 4.0000 603008 (Eh, vu1gar15) 4.0333 603235 (Eh, vu1garis) 4.1000 604487 (Eh, vu1qaris) 4.1333 601051 (Eh. vu1qaris) 4.2000 603027 (Eh_. vu1garis) 4.2333 604298 (Eh, vu1garis) 4.2333 603145 (Eh, vu1qaris) 4.2333 603165 (Eh. vu1garis) 4.2667 601225 (Eh, vu1aaris) 4.3000 600718 (Eh, vu1garis) 4.3000 600808 (Eh, vu1gar15) 4.3333 603115 (Eh. vu19aris) 4.3333 603167 (Eh, vu1garis) 4.4333 601083 (Eh. vu1 aris) 4.5667 603099 (Eh, vuigaris) 4.5667 604494 (Eh, vu1qaris) 4.6000 603242 (Eh, vu1qaris) 4.6333 603178 (Eh, vu1qaris; 4.6333 603252 P . vu1garis 4.6333 602987 (E. vu1oaris)> 4.6333 600039 EE—h,____y coccineus) 4.7000 603042 P vu1 aris 4.7333 1-59 (P Evu1 ar151 4.7667 Rayada? vu1 aris) 4.8667 602997 vu1 aris) 4.9000 601204(.vu10ar1s) 5.0000 Tab1e 3. Adu1t preference for severa1 p1ant parts (1aboratory study) (Data ana1ysed= Arcsine transformed). 3a. ANOVA for the overa11 adu1t attraction for the 38 bean cu1tivars. 89 Cont. appendix, Tab1e 3a. Source of variation DF SS MS F B1ocks 2 0.2739 0.1369 1.918 Cu1tivars 37 6.9643 0.1882 2.636 ** Error 74 5.2848 0.7142 Tota1 113 12.5230 3b. ANOVA for 1eaf-b1ade adu1t attraction for the 38 bean cu1tivars. Source of variation 0F SS MS F B1ocks . 2 0.3184 0.1592 3.233 * Cu1tivars 37 0.5375 0.1453 2.950 ** Error 74 0.3643 0.4924 Tota1 113 0.9336 3c. ANOVA for shoot adu1t attraction for the 38 bean cu1tivars. Source of variation DF SS MS F B1ocks 2 6.8346 3.4173 0.987 Cu1tivars 37 3.2720 8.8433 2.555 ** Error 74 2.5610 3.4607 Tota1 113 5.9013 3d. ANOVA for petio1e adu1t attraction for the 38 bean cu1tivars. Source of variation 0F SS MS F B1ocks 2 0.1534 0.0767 2.422 Cu1tivars 37 2.2605 0.0611 1.929 ** Error 74 2.3432 0.0317 Tota1 113 4.7571 90 3e. ANOVA for stem adu1t attraction for the 38 bean cu1tivars. Source of variation DF SS MS F B1ocks 2 0.0250 0.0125 1.254 Cu1tivars 37 0.5412 0.0146 1.467 Error 74 0.7376 0.0100 Tota1 113 1.3038 3f. ANOVA for chamber adu1t attraction for the 38 bean cu1tivars. Source of variation DF SS MS F B1ocks 2 0.3072 0.1536 2.099 Cu1tivars 37 0.7006 0.1893 2.588 ** Error 74 0.5415 0.0732 Tota1 113 0.1273 ** Significant at P=0.01 * Significant at P=0.05 11111111111111111111111111111111111111111111111111111111! 707814