Insect Physiology Laboratory, Department of Zoology, Aligarh Musiim University, Aligarh-202002, Uttar Pradesh, (India).
The 4th-instar nymphs of Dysdercus cingulatus Fabr. were individually treated with 6, 4, 2, 1, and 0.5 μg doses of two analogues of β-ecdysone (22,25-dideoxyecdysone and 2,22,25-trideoxy-5β-hydroxyecdysone) to observe their effects on the fecundity and fertility of the emerging females. The egg production as well as egg viability of such adult females decreased linearly and showed negative correlation with the increasing dose levels. After the application of the highest dose (6 μg/nymph) of 22,25-dideoxyecdysone, the maximum reduction in the egg production and egg hatching of the females that emerged from the treated nymphs was 30.85 and 35.28%, respectively as compared to control. But, the same dose of 2,22,25-trideoxy-5β-hydroxyecdysone resulted in 27.55 and 29.18% reduction in fecundity and fertility of the females which was 3.3 and 6.1% less when compared with 22,25-dideoxyecdysone, respectively. However, both the analogues of β-ecdysone may be considered as deterrents to check the population of D. cingulatus.
