DOI: 10.36347/sajb.2018.v06i10.004

Pages: 643-659

The cotton leafworm, Spodoptera littoralis is a serious pest of cotton and field crops in Egypt and many countries in the world. The objective of the current investigation was to evaluate the effects of Fluoromevalonate (FMev), on survival, development and reproductivity of this pest. For this purpose, four doses (100, 50, 25 and 5 µg/larva) had been topically applied onto the newly moulted 5th and 6th (last) instar larvae. A weak lethal potency was recorded for FMev against all developmental stages. After treatment of 5th and 6th larval instars, LD50 values were 42.03 and 629.20µg/larva, respectively. The growth of larvae was inhibited after treatment of 5th instar larvae, but enhanced after treatment of 6th instar larvae. The larval duration was significantly shortened, but the pupal duration was slightly or remarkably prolonged. The pupation and adult emergence had been inhibited. Treatment of 6th instar larvae with the three higher doses of FMev resulted in the production of malformed pupae. Depending on the present results, FMev failed to exhibit an anti-JH activity, but exhibited a powerful anti-gonadotropic activity against S. littoralis, since complete sterilization was recorded.