Some Effects of Synthetic Juvenile Insect Hormones and Hormone Analogues on Tribolium Castaneum (Herbst).

Abstract

The effects were studied of incorporating three synthetic insect juvenile hormones and five analogues in flour diets for T. castaneum. The synthetic hormones used were: methyl 10,ll-epoxy-7-ethyl-3,ll-dimethyltrideca- 2,6-dienoate (compounds I and II; these had the same structure but consisted of different isomer ratios), and methyl cis-l0,11-epoxy-3,7,11-trimethyltrideca-trans-2,trans-6-dienoate (III). The analogues used were: 6',7'-epoxy-3',7'-dimethyloct-trans-2'-enyl 3,4-methylenedioxyphenyl ether (IV); 3'-methyl-7'-ethylnona-2',6'-dienyl 3,4-methylenedioxyphenyl ether (V); ethyl 3,7,11-trimethyldodeca-2,4-dienoate (VI); isopropyl 11-methoxy-3,7,11-trimethyldodeca-2,4-dienoate (VII); 6',7'-epoxy-3',7'-dimethyloct-trans-2'-enyl 4-ethylphenyl ether (VIII). Compounds II-VII were incorporated in flour media at concentrations of 5 and 20 p.p.m. and I and VIII at 5 p.p.m. only. The number of eggs laid in various treated media did not differ significantly from that in the control. Egg to adult development was inhibited by VII and VIII at 5 p.p.m. and by II, IV and VI at 20 p.p.m. Development was completed in other treatments but with a high level of adult morphological deformity except with V and VI at 5 p.p.m. The compounds tended to increase the developmental period from egg to adult.