9305809 Lee Collaborative research between investigators at Miami University and Ohio State University will focus on physiological mechanisms used by insects for overwinter survival. Both the entry into diapause and cold hardening are essential for survival of most temperature zone species. This study examines mechanisms utilized by two types of insects, one that can not tolerate freezing (the flesh fly, Sarcophaga crassipalpis) and a species that tolerates extensive internal ice formation (the goldenrod gall fly, Eurosta solidaginis). The presence of ice nucleating agents play a critical role in determining the temperature at which an insects freezes. One part of the project will focus on the role of these ice nucleates, including yeast, bacteria and crystals of calcium phosphate, in determining seasonal changes in the supercooling point. A second part examines the nature of cold injury using crymicroscopy and vital dyes to directly observe the effects of chilling and freezing on insect cells. Additional experiments will probe the nature of cold injury inflicted on the neuromuscular system. Our recent discovery that insects produce stress proteins in response to cold exposure suggests that such proteins may play an important role in providing cold tolerance. Experiments are designed are designed to determine the relationship between stress protein synthesis and the acquisition of cold tolerance. This work will not only provide an understanding of new mechanisms of cold tolerance, but may provide new tools for disruption of insect pest populations, and for long term storage of insects and other organisms at low temperature. *** v s t $ $ ( F / C Dutch (scalable) Symbol " Swiss (scalable) 5 Courier New i " h e e ( G R:WW20USERABSTRACT.DOT Rochelle D Ray Rochelle D Ray