ENDOCRINE REGULATION OF REPRODUCTION AND DIAPAUSE IN THE BOLL-WEEVIL,ANTHONOMUS-GRANDIS BOHEMAN

A review of the literature for the hormonal control of reproduction an d diapause in Coleoptera is presented. The role of juvenile hormone an d juvenile hormone esterase (JHE) in the control of the different life history strategies of the boil weevil are examined. Elevated levels o f hemolymph JHE were found to be positively correlated with survival t hroughout the winter in South Texas population of weevils. Winter weev ils were examined for hemolymph vitellogenin (Vg) and their subsequent survival was monitored. The majority of weevils surviving beyond ten weeks had no hemolymph Vg. We conclude that elevated hemolymph]HE and the absence of Vg are good predictors of survivors in the South Texas population. The hormonal basis of diapause termination was examined us ing hormone treatment and implant therapy. We were unsuccessful in our attempt to induce post-diapause reproductive development with all of our treatments. Only weevils given access to a food source were capabl e of reproductive development. Our recent experimental findings in the control of Vg synthesis and uptake in the boil weevil are reviewed. ( C) 1997 Wiley-Liss, Inc.