Research in our laboratory focuses primarily on molecular mechanisms involved in insect overwintering. For most insects, seasonal changes in daylength provide the environmental signal that winter is coming. This, in turn, prompts preparative steps that eventually lead to a developmental arrest (diapause) as well as enhanced cold tolerance. Our interests range from the use of clock genes to perceive these environmental signals through to the endocrine and molecular events that result in expression of the diapause phenotype. Currently, our model systems for diapause studies include flesh flies (Sarcophaga crassipalpis and S. bullata which both have a pupal diapause), members of the Heliothis/Helicoverpa complex of agricultural pests, which all have a pupal diapause), the Asian tiger mosquito (dengue vector Aedes albopictus which has an embryonic diapause), and the Northern house mosquito (West Nile virus vector Culex pipiens, which diapauses as an adult). In addition, we are engaged in research in Antarctica, where we are examining how a midge, Belgica antarctica, survives in this hostile environment. Our laboratory has also maintained a long-term interest in reproductive physiology of the tsetse fly, vector of African sleeping sickness.