Test of a New Insect Growth Regulator for Boll Weevils (Coleoptera: Curculionidae) by Dipping and Feeding

Boll weevils, Anthonomus grandis grandis Boheman, dipped into solutions containing 0.25-2.0% of CIBA-GEIGY’s CGA-184699 killed >40% after 1 wk. Feeding 0.25-1.5% of this material in the adult diet for 3 d produced mortality similar to that found in tests. Female boll weevils treated with this insect growth regulator by dipping or feeding and mated with untreated males resulted in 95-99% less egg laying compared with the control. Male boll weevils administered CGA-184699 by dipping or feeding and mated with untreated females produced 58.8-73.0% fewer eggs compared with the control. Egg hatch and adult emergence of the few eggs collected was reduced to virtually zero in dipping and feeding tests.