Abstract— Hibiscus is an important plant cultivated in large numbers in Indian systems of medicine and perfumery. Haritalodes derogata is a common pest of Hibiscus species, feeding on their leaves in large numbers and causing considerable loss in harvest. In the present study, last instar larvae of H. derogata were fed with leaf extracts of Azadirachta indica and Ocimum tenuiflorum. Mortality, pupation success, and adult emergence were monitored over 14 days. A. indica extract caused significantly higher and faster mortality compared to O. tenuiflorum, resulting in 100% mortality by Day 5. It also induced larval body shrinkage, production of orange-coloured fluid fecal matter, and complete inhibition of pupation. In contrast, O. tenuiflorum caused only 12.5% mortality by Day 5, with most larvae proceeding to pupation and adult emergence, though adults died subsequently. The findings demonstrate the superior efficacy of A. indica extract as a potent botanical insecticide for managing H. derogata infestations.
Dr. Thanuja A Mathew (Sat,) studied this question.