PHOTOTOXICITY OF CITRAL TO TRICOPLUSIA NI (LEPIDOPTERA, NOCTUIDAE) AND ITS AMELIORATION BY VITAMIN-A

Citral, a monoterpene aldehyde synthesized by several plant families, was recently shown to exhibit ultraviolet A light (320-400 nm) (UVA)-e nhanced oxygen-dependent toxicity against bacteria and fungi (Escheric hia coli and Fusarium species). In this study, we report for the first time that citral is phototoxic to insects; at concentrations of 300 p pm in artificial diet, mortality of first instar Trichoplusia ni (cabb age loopers) approached 30% after 120 h of UVA exposure, approximately double the mortality level in the absence of WA. At 300 ppm, the anti oxidant vitamin A reduces citral phototoxicity by about 50% in this sp ecies, suggesting that citral phototoxicity against insects is oxygen dependent.