INITIATION OF MATERNAL EFFECTS IN LYMANTRIA-DISPAR - GENETIC AND ECOLOGICAL COMPONENTS OF EGG PROVISIONING

Resources supplied by mothers to offspring through the egg are known t o significantly influence offspring life history traits in the gypsy m oth, Lymantria dispar. The purpose of this research was to determine t he relative contribution of genetics (based on familial contribution) and the nutritional environment of the parents to the mean and varianc e of resources supplied to the eggs. Vitellogin, the dominant egg stor age protein in the gypsy moth, was selected as the focus of the study. The amount of vitellogin in individual eggs from 48 mothers reared on one of four host species. quaking aspen, chestnut oak, red oak, or pi tch pine was quantified with an immunoassay. Results of a nested analy sis of variance show that both genetics and parental nutritional exper ience make significant contributions to egg vitellogin levels. When pa rents were reared on quaking aspen, vitellogin levels were highest and the expression of familial variation was greatest. This study shows t hat polyphagy can amplify phenotypic variance in reproductive traits t hrough the interaction between genotype and nutritional environment. T o the extent that egg resources influence offspring vigor, the fitness of offspring can include a time-lagged component which arises from th e interaction between the parental genotype and the parental environme nt. The time-lagged expression of such a maternal trait is capable of influencing the rate and direction of character evolution and the stab ility of local population dynamics.