Genetic variation in response of the gypsy moth to aspen phenolic glycosides

We investigated genetic variation in response of a wild strain of gypsy moths, Lymantria dispar, to phenolic glycosides isolated from Populus. For 12 families, first instar survival varied little among family groups fed a control artificial diet, but LT 50 values differed significantly among groups fed an artificial diet containing phenolic glycosides. First instar survival rates were positively correlated with esterase enzyme activity. Relative growth rates of fourth instars were influenced by diet and by family. A nearly significant dietXfamily interaction term indicates that family (genotype) influences gypsy moth response to phenolic glycosides. Prior consumption of phenolic glycosides induced esterase activity in fifth instars. Esterase activity was influenced by diet, family and dietXfamily interaction. Genetic variation in esterase activity may explain variation in larval response to phenolic glycosides.