Synergistic insecticidal mode of action between sesquiterpene lactones anda phototoxin, alpha-terthienyl

The synergistic insecticidal action of characteristic defensive substances produced by the plant family Asteraceae was investigated under controlled l aboratory conditions. Sesquiterpene lactones isolated from Asteraceae that may form, through a Michael addition process, conjugates with glutathione w ere administered in a meridic diet to a herbivorous insect, Manduca sexta, By administering sesquiterpenes, variable in vivo reduced glutathione level s were observed in the insect larvae. When the Asteraceae-derived photooxid ant alpha-terthienyl was co-administered, lipid peroxidation and larval mor tality were significantly enhanced in the treated groups of insects with lo wered in vitro glutathione levels.