Effect of Different Applicable Conditions of the Insect Growth Regulator (Cyromazine) on the Southern Cowpea Weevils, Callosobruchus maculatus Reared on Peas

Journal Article

مستخلص المنشور

This study investigates the effect of different concentrations of the growth regulator (Cyromazine), temperature and treatment methods on the reproductive rate, generation lifespan and weight loss of the Southern cowpea weevils Callosobruchus maculatus (Coleoptera: Bruchidae). Data showed that weevils failed to complete their life cycle on the host peas, Pisum sativum, pre-dipped in a 5% cyromazine at 30°C. Cyromazine-dipped peas seeds were protected from insect attack comparing to cyromazine-sprayed seed. Moreover, increasing the cyromazine concentration increased the average period of insects generation since the longest generation period recorded from cyromazine-sprayed insects at 25°C was 42.33 day post-treatment. Increasing cyromazine concentration reduced the percentages of pupation and adult emergence down to19.83 and 27.08%, respectively compared to control treatment which were 87.33 and 88%, respectively. The results showed little overlapping effect on the three factors on the sex ratios and the mean weight of male and female.