Juvenile hormone activity for the bug Pyrrhocoris apterus.

Abstract

Materials composed of American paper pulp contain an extractable, heat-stable lipid which exhibits extremely high juvenile hormone activity when injected or topically applied to the European bug Pyrrhocoris apterus. The active principle in the paper materials is derived from certain species of pulp trees, more particularly the balsam fir, Abies balsamea. Larvae exposed to the active material ultimately die without completing metamorphosis or attaining sexual maturity. Despite its extremely high activity for Pyrrhocoris apterus, the extract is without any detectable effects on silkworm pupae; conversely, juvenile hormone extracts prepared from cecropia silkmoths show only a trace of activity when tested on Pyrrhocoris. These findings point to a diversification of the detailed chemistry of juvenile hormone during insect evolution. The factor extracted from paper materials promises to be an effective agent for the selective control of insect pests which show the same endocrine sensitivities as Pyrrhocoris apterus.