Insects are extremely abundant and diverse. Their ecological importance may outweigh that of other animal groups in both natural and managed ecosystems. To foster beneficial roles of insects while reducing their adverse effects, it is crucial to understand insect behaviors and address its implications for applied ecological questions. Therefore, my research group has focused on studying behavioral ecology of several economically important pests including whiteflies, stink bugs, bean bugs, mosquitoes, and ticks. In this talk, I will present classical and new techniques to study behaviors of the insects and some of the important findings, especially about dispersal and overwintering ecologies.

An invasive pest is a non-native species which can cause damage to the economy, natural resources, or human health. The invasion of these non-native species is an escalating problem worldwide. In particular, it is estimated that ca. 50,000 nonindigenous species have been introduced into the United States, many of which have caused a total of > $100 billion losses in natural and agricultural ecosystems. Recently, two invasive pests, Halyomorpha halys (Hemiptera: Pentatomidae) and Drosophila suzukii (Diptera: Drosophilidae), have emerged as serious agricultural pests in the U.S. Both species are native to Asia, however the distributions of the pests have rapidly expanded across the U.S. causing significant economic losses especially in specialty crops, presumably due to similarities in host plant complex and climatic environments between the native and new regions. In this study, a series of research efforts to protect agriculture and the environment against H. halys and D. suzukii in the U.S. are summarized and reviewed.

Invasive species are a major threat to ecosystems and cause enormous environmental and economic losses. Although it is difficult to estimate the full extent of the environmental damage by exotic species and control costs, it is estimated that invasive species cause > $100 billion in losses per year in the United States alone. The brown marmorated stink bug (BMSB), Halyomorpha halys, is native to Asia, but has become a recent example of serious biological invasion, expecially in the US. The BMSB is a voracious eater that damages fruit, vegetable, and ornamental crops in North America. To manage this destructive invasive pest, a team of more than 50 researchers is studying the pest's biology, behavior and ecology to find management solutions for growers, seeking strategies that will protect food, environment and agricultural industry. In this study, I address how the BMSB team were able to make successful team effort to battle the invasive species with funding from the USDA's Specialty Crop Research Initiative.

Recently, it has been demonstrated in several predator-prey interactions that predators influence prey population dynamics by inducing behavioral changes in prey as well as by feeding on prey. Accumulating evidence supports that prey change habit use patterns and activity levels in repose to predation risks. In the studies reported here, we examined the resource use patterns by adult whitefly, Bemisia argentifolii (Hemiptera: Aleyrodidae) in response to its natural enemies. The first study examined whether, in the context of a trap crop system, differential predation risks among plants influence host choice patterns of adult whiteflies. We investigated whether whiteflies avoid natural enemies inhabiting a cash crop (poinsettia) and whether this behavior can be used to increase the movement of whiteflies to a trap crop (cucumber). Three natural enemies were tested: two predators, Amblyseius swirskii and Delphastus catalinae and a parasitoid Encarsia formosa. The presence of D. catalinae on cash crop induced significantly more whiteflies to disperse to predator-free trap crop, compared with cash crop with no predator. A. swirskii and E. formosa did not result in a significant increase. The second study examined habitat choice patterns by adult whiteflies in response to D. catalinae at different spatial scales. When female whiteflies were confined in small leaf-disc arenas, whiteflies significantly delayed settling on leaf-discs with predators compared those with no predators. The presence of D. catalinae altered the vertical distribution of whiteflies on cucumber plants. Whiteflies moved upward faster over time within the plant canopy when predator were present at lower canopy compared with plants with no predator. However, D. catalinae did not result in elevated between-plant movement of whiteflies in the greenhouse, compared with that with no predator. Predator avoidance behavior by adult whiteflies should be considered in the development of biological control programs.