Effects of Fenitrothion and Aminocarb, at Doses Giving Low Mortality, on Surviving Eggs and Larvae of the Eucalypt-Defoliating Chrysomelid Beetle Paropsis Atomaria Ol. Ii. Biology of Survivors.

Abstract

Mortality of P. atomaria eggs treated with fenitrothion or aminocarb increased with the dose level, fenitrothion being the more effective. Larvae from eggs treated with fenitrothion and all but the two lowest concentrations of aminocarb died within periods of up to 10 days, depending on dosage. Fenitrothion caused higher mortality of second- and fourth-instar larvae, but aminocarb retarded their growth the more; growth was progressively retarded with increasing dose. Surviving fourth-instar larvae treated with aminocarb recovered, and by 96 h after treatment their growth was less retarded than that of fenitrothion-treated larvae. Growth retardation was due to poor utilization of food. Longevity, fecundity and fertility of adults from treated larvae were also affected. Egg and larval endoparasites were not affected.