Effects of certain chemosterilants and biologically active substances on the adult Mediterranean flour moth,Ephestia kuehniellaZeller (Lepidoptera: Pyralidae)

Abstract

AbstractOf 11 chemosterilants tested on adult males ofEphestia kuehniellaZell., only tepa induced complete sterility. It also induced complete sterility in females ofE. kuehniella. Hempa showed weak sterilising activity against adult males and had no sterility effect against the females, even at dose levels that induced high mortality. Cycloheximide induced slight sterility in the males. Carbaryl was inactive as a sterilising agent but induced some of the males to produce spermatophore sacs without mating. The latter effect was also induced in a few males by injection of tri-, penta- or hexamethylmelamines, which also induced significant infertility in eggs of untreated females mated with treated males. No structure-activity relationship existed in this group of compounds. Hemel also induced two mating aberrations: permanent copulation and sterile mating. A juvenile hormone analogue (a mixture of 3 hydrochlorinated farnesoates with activity about 1% of that of natural juvenile hormone) induced significant sterility in adult females ofE. kuehniellawhen applied topically. It also caused 38–41% reduction in oviposition at 50–80 μg/adult. However, at 100 μg/adult, the analogue completely inhibited mating in the females. Injected doses of melatonin also caused significant reduction in oviposition. At 5·3 μg/adult, it induced most of the eggs laid to undergo incomplete development. The effects of these compounds are discussed. The sterility indices of tepa against adult male and femaleE. kuehniellawere 19·5 and 9·2, respectively; that for hemel against males was 1·4.