Sterilization of mango nut weevil, Sternochetus gravis (Fabricius) by thiotepa and hempa

Fumgigation of adult Sternochetus gravis (Fabricius) at atmospheric pressure with thiotepa (100 mg Tech,) and hempa (1 ml) induced sterility in both sexes. Both chemosterilants induced more egg laying, as compared to control, in females mated with treated males. The reverse was true in case of treated females. The fertility was more in eggs oviposited by treated females as compared to those laid by females mated with treated males. With increase in exposure period of fumigants from 1 to 3 hrs, the mortality of adults slightly increased by did not affect reproduction control which varied from 98.77 to 99.97 percent in all treatments. Mortality of treated weevils was 15 to 31.7 percent at 7 days post-treatment. Final evaluation of its potential to nut weevil control and eradication programme can be made only after such field tests have been concluded.