Sublethal Effects of Fenvalerate on Adults of the Diamondback Moth (Lepidoptera: Plutellidae)

Long-term sublethal effects caused by brief tarsal contact with insecticide residues were investigated by rearing female-male pairs of diamondback moths, Plutella xylostella (L.), in which one member had walked for 1 min in a glass tube internally coated with fenvalerate (250 ng[AI]/cm2). Survivorship at 48 h after treatment was 52%. Fifty-two percent of the surviving moths had autotomized one or more legs. Treatment did not affect long-term survival, but fecundity was reduced regardless of which sex was treated. All moths that autotomized were able to reproduce, but their fecundity was only 48% of that for treated moths that did not drop legs.