This thesis focuses on pest dynamics and pest control services of the invasive brown marmorated stink bug (Halyomorpha halys). The first chapter investigates the role of landscape complexity in the strength of pest suppression services by native parasitoids, and the establishment success of an exotic parasitoid, Trissolcus japonicus, for biological control of H. halys. To do this, ten sites were selected across the southwestern region of Michigan for their varying degrees of landscape complexity and suitable parasitoid habitat. In 2021, 2,000 T. japonicus adults were released at each site. Parasitoid releases were followed up with monitoring in 2021 and 2022 to assess Tr. japonicus establishment. The factors that contribute to the establishment of an introduced biological control agent were different from those affecting native parasitoid populations. Metrics associated with increased landscape complexity had no effect or a negative effect on parasitoid establishment, suggesting that the effect of landscape complexity on natural enemy populations cannot be generalized.The second chapter explores environmental, temporal, and landscape factors that have contributed to population fluctuations of H. halys between years and growing regions. A span of four years (2018-2021) of H. halys monitoring data at 20 sites was used to compare annual population estimates to various weather variables to understand how seasonal weather changes may disrupt or promote population booms or busts. Our study confirms that weather is one of the factors driving differences in annual abundance of H. halys. We found that the susceptibility to weather conditions is dependent on life stage, but more research is needed to understand real-time population responses to weather events.
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