Phenotypic Response of Two Successive Gypsy Moth (Lepidoptera: Lymantriidae) Generations to Environment and Diet in the Laboratory

Abstract

A 2-generation comparison documented variables affecting performance of gypsy moth, Lymantria dispar (L.), reared under laboratory conditions, including differences in environment (different locations), substrains (isolated over time), and diet (preparation and ingredients) Gypsy moth colonies have experienced unpredicted periods of poor hatch, reduced survival, and slow asynchronous development that have collectively been called abnormal performance syndrome (APS). Substrain differences were found but were not linked to the expression of APS. Parental rearing environment affects development and survival of larvae of both the parent and progeny generations, but only influences the degree of expression of APS. The expression of APS results from a dietary problem; sensitivity varies within and between families. In addition, the phenotype of the individual (whether it expresses APS or not) appears to depend not only on its own genotype but on the interaction between its parent genotypes and the diet they fed upon. The importance of these findings for laboratory reared insects in general are discussed.