EFFECTS OF CARTAP, A NEREISTOXIN ANALOGUE INSECTICIDE ON THE PUPAL AND ADULT STAGES OF SWEET POTATO WEEVIL, Cylas formicarius FABR (COLEOPTERA: CURCULIONIDAE)

摘要

Cartap hydrochloride, a Nereistoxin analogue insecticide was tested on freshly moulted pupae and adults of Sweet Potato weevil, which is a serious pest of sweet potatoes at different concentrations, and the results are reported. In the pupal treatments, at higher concentrations, a high mortality was obtained while at the lower concentrations, the mortality rate was decreased. There was a preponement of the moulting process at a higher concentration. The pupae tried to moult on fifth day itself (one day earlier) and died in the process. At lower concentrations, pupae produced adults with deformities. In such cases, cartap exhibited a JH like activity. In treated adults, the mortality rate was concentration dependent. The feeding activity of the adultweevils was also affected. It also affected the reproductive systems of both treated male and female insects. SWEET POTATO is cultivated on a large scale in India. It is grown practically in all the states. It has high nutritive values. The Sweet Potato crop is severely infested and damaged by Sweet Potato weevil (Cylas formicarius F). The weevil damages the crop in its adult and grub stages. The adults bore into the tubers of Sweet Potato for egg laying and feeding. The infested tubers become unfit for human consumption because of not only the presence of grubs but also due to a bitter taste.