UNITED STATES GREEN SECTION GOLF ASSOCIATION EASTERN REGION N O R T H E A S T E RN D I S T R I CT M I D - A T L A N T IC D I S T R I CT R U T G E RS U N I V E R S I TY NEW B R U N S W I C K. NEW J E R S EY P L A NT I N D U S T RY S T A T I ON B E L T S V I L L E, MARYLAND EASTERN TURFLETTER A L E X A N D ER M. RADKO E A S T E RN D I R E C T OR C H A R L ES K. H A L L O W E LL M I D - A T L A N T IC D I R E C T OR T. T. N O R T H E A S T E RN AGRONOMIST T A Y L OR No* 5 October, 1959 CRAMBUS CAPERS! i The sodwebworm (Crambus sp.) invaded the Northeast this season in numbers far above anything seen by us in prior years. Whatever the magic combination necessary — this season must have been "it ... for several golf courses experienced severe infestations ..• mainly on fairways.. This has been one of the few years that it has been a major problem on Northeastern courses — reports from the Southern courses indicate that it is an important problem there almost yearly. Perhaps the fact that our summer here was similar to that of the Deep South may have prompted the increase. 11 Normally the larva of this insect pest is quite difficult to find — however such was not the case this season — maybe because they were so numerous. They are grayish green worms approximately 1/2 to 3/li inch long (they look somewhat like a miniature cutworm). They burrow into the soil and line their tunnel with a silken web* Like most insects of economic importance they are experts at camouflage and further reinforce their tunnels with organic matter, pieces of grass, and bits of soil. The adult is a tanish gray or grayish tan moth (or miller) frequently observed on turf areas. Usually any movement, such as walking over the area or mowing it, flushes the moth from its grass abode. It seems to play "leap frog" in front of the intruder — ever pressing forward in short erratic flights. Their greatest activity is in the evening, on to nightfall. There are more than 60 species of webworm in the United States, but only a dozen are of economic importance. The adult moth drops its eggs at random as they fly over the turf. They seem to have a sixth sense regarding the best areas over which to drop their eggs — and seem to favor watered turf , which would make it easy for the larvae to burrow into the softer soil. They also favor grasses that tend to thatch such as creeping bentgrass, Merion bluegrass, bermudagrass, and Zoysia. The young v/orms hatch anywhere from 7 to 20 days and the larval and pupal stages average about 2 weeks each. During July and August, broods arise more rapidly than during the spring and Autumn. This year, due to the extended period of sunnier temperatures through part of October, activity of the sodwebworm was pronounced from July through mid-October. There may be two or more broods diring the year. This year D r. John Schread, Entomologist of the Connecticut Agricultural Experiment Station, reported in early September that there were £ broods to that time, and felt another brood would develop in Connecticut before the close of the Autumn season* The injury caused by the webworm is such that it is easily confused with other troubles. It could be mistaken for dollar spot, wilt, or even fertilizer burns. Injured areas first appear somewhat like dollarspot, ana as the webworm feeds the afflicted areas quickly coalesce and may take out large areas, of turf at a time. As it pro- gresses from early to late stages, the injury appears to be that of dryness — the area suddenly seems to be in need of water — and the turf turns brown rather fast. ,It is somewhat similar to injury caused by chinchbugs, cutworm, or sucking insects — only the webworm seems to take out larger areas of turf quicker. Fortunately the controls are good for this insect pest. Any one of a number of insecticides qould be used — chlordane, Dieldrin, Aldrin, and DDT have been used most often. Diazinon is a new insecti- cide that also shows good promise for leaf feeding insects ... has been reported excellent for chinchbug control. The usual rate for leaf feeders is between 1/3 and 1/2 the normal application for grubs. Because the sodwebworm is a leaf feeder (it feeds at night) insecticide applied last year or the year before will not control them. Usually the insecticide is leached down beyond the effective range of control, hence when sodwebworm activity is observed it is important to apply some insecticide quickly regardless of when the last treatment was applied. Protection against grubs primarily is assured for several years with one application of insecticide at normal rates — leaf feeders however are another matter, and it may be necessary to treat yearly for them. Since activity is more pro- nounced when temperatures are high, it would usually be best to apply insecticide in July. Normally if you cut down one brood, the next would be less likely to be trouble some. In the South where sodwebworms generally are a more serious problem, Dr. Marvin Ferguson, Jim Latham, and Jim Moncrief of the Green Section staff in their Southern Turfletter advise applying the insecticide onto the foliage in the late afternoon or evening and allow it to remain overnight. Although the webworm has not been a serious problem in the Northeast each year, we learned this year how quickly turf loss can occur unless yje recognize the problem quickly. Because infestations were heavy this year, there is a chance that next year's activity may also be heavy • •• if season is favorable. Some Other Observations on the Season When nature is on a rampage — management practices that could hurt must be done in moderation. The foundation on which good turf is produced is drainage. Poa annua is no friend when temperatures and/or humidity hover f in the 9 0 s for weeks. There is one thing that acts faster than greased lightning ... Wet Wilt I A fairway watering system is by no means insurance against turf loss* f Saturday and Sunday are week days when the weather ain t right 1 — wilt takes no holiday. Poor turf growing weather often is good playing weather — 1 and oh that traffic. January 5 -6 January 18 - 21 Jan, 27 - Febr. 6 February 15 - 18 March 10 - 11 1J CCMING EVENTS Mid-Atlantic Turfgrass Conference Lord Baltimore Hotel Baltimore, Maryland New Jersey Turfgrass Conference Rutgers University New Brunswick., N. J. 31st Annual Conference Golf Course Superintendents of America Shamrock Hilton Houston, Texas Penn State Turfgrass Conference Perm State University University Park, Pennsylvania Massachusetts Turfgrass Converence University of Massachusetts Amherst, Mass, OS ID MO.. 3.66 [NEW BRUNSWICK, N. J I USGA GREEN SECTION MR. WILLIAM BENGETFIELD U. S. GOLF ASSN. ( H EM SECTION Box $67 garden grove, calif.