PHOTOTOXICITY, PHARMACOKIENTICS AND METABOLISM OF ALPHA TERTHIENYL IN SENSITIVE AND RESISTANT HERBIVOROUS INSECTS

摘要

Thlophenes are among the major secondary substances of the plant family Asteraceae. The role of a phototoxic representative of these compounds, α-terthienyl, as part of the chemical defence of composites against 3 species of herbivorous insect, was investigated. The compound was administered either topically on the dorsal surface of the insect or incorporated in an artificial diet and fed to insects. Alpha-terthienyl was highly phototoxic to the tobacco hornworm, Manduca sexta and the cabbage butterfly, Pieris rapae (topical LD_(50) for last instar larvae were 10 and 15 μg/g respectively). It was less phototoxic to the European corn borer, Ostrinia nubilalis or the tobacco budworm Heliothis virescens (LD_(50) 698 and 474 μg/g respectively).