Insecticidal Activities of Synthetic Pyrethroids

Abstract

Pyrethroids (natural and synthetic ones) are becoming increasingly important as insect control agents because they possess a unique combination of desirable properties including exceptionally good insecticidal activity, low mammalian toxicity, and rapid biodegradation. These features, combined with their broad spectrum of insecticidal activities, have made them commercially successful, and also environmentally safe. There have been desired synthetic insecticide having higher toxicity on insects, lower cost, lower mammalian toxicity and some unique properties for actual uses. In general, the uses of pyrethroids are mainly limited by high cost and by their instability for certain possible uses. RESULTS AND DISCUSSION It was recognized by Nakada and collaborators (1) that several compounds were isolated by pyrolysis of allethrin heated at 400°C. Two of the compounds obtained by the pyrolysis were indanone derivatives as shown in Fig. 1. These indanones showed themselves weak insecticidal activities. The activity was measured by using first instar nymphs