Preface. Foreword (J.W. Truman). 1. The blow fly Calliphora vicina: a "clock-work" insect (D.S. Saunders). 2. Molecular control of Drosophila circadian rhythms (P. Schotland, A. Sehgal). 3. Organization of the insect circadian system: spatial and developmental expression of clock genes in peripheral tissues of Drosophila melanogaster (J.M. Giebultowicz, M. Ivanchenko, T. Vollintine). 4. The circadian clock system of hemimetabolous insects (K. Tomioka, A.S.M. Saifullah, M. Koga). 5. Cellular circadian rhythms in the fly's visual system (E. Pyza). 6. Anatomy and functions of the brain neurosecretory neurons with regard to reproductive diapause in the blow fly Protophormia terraenovae (S. Shiga, H. Numata). 7. Photoperiodism and seasonality in aphids (J. Hardie). 8. Photoperiodic time measurement and shift of the critical photoperiod for diapause induction in a moth (S. Masaki, Y. Kimura). 9. Geographical strains and selection for the diapause trait in Calliphora vicina (D.S. Saunders). 10. Evolutionary aspects of photoperiodism in Drosophila (M.T. Kimura). 11. Molecular analysis of overwintering diapause (S.R. Palli, R. Kothapalli, Q. Feng, T. Ladd, S.C. Perera, S.-C. Zheng, K. Gojtan, A.S.D. Pang, M. Primavera, W. Tomkins, A. Retnakaran). 12. Insights for future studies on embryonic diapause promoted by molecular analyses of diapause hormone and its action in Bombyx mori (O. Yamashita, K. Shiomi, Y. Ishida, N. Katagiri, T. Niimi). 13. Stress proteins: a role in insect diapause? (D.L. Denlinger, J.P. Rinehart, G.D. Yocum). 14. Regulation of the cell cycle during diapause (S.P. Tammariello). 15. Significance of specific factors produced throughout diapause in pharate first instar larvae and adults (K. Suzuki, H. Tanaka, Y. An). 16. Surviving winter with antifreeze proteins: studies on budworms and beetles (V.K. Walker, M.J. Kuiper, M.G. Tyshenko, D. Doucet, S.P. Graether, Y.-C. Liou, B.D. Sykes, Z. Jia, P.L. Davies, L.A. Graham). 17. Using ice-nucleating bacteria to reduce winter survival of Colorado potato beetles: development of a novel strategy for biological control (R.E. Lee, Jr., L.A. Castrillo, M.R. Lee, J.A. Wyman, J.P. Costanzo). Species index. Subject index.