Life-history Traits of Forest-inhabiting Flightless Lepidoptera

Abstract

Some species of forest-inhabiting Lepidoptera possess a set of life-history traits including flightless females, larval dispersal by ballooning, polyphagy, univoltinism and overwintering larvae or eggs. Convergence in these life-history traits occurs in species from the Geometridae, Lymantriidae and Psychidae. Ecological factors in the forest habitat which probably contribute to this convergence include habitat stability, resource persistence, convergence in tree chemical defense and phenological variability in bud-break. These life-history traits contribute to the ability of these species to reach high population density during years favorable to larval growth and survival resulting in the economic importance of these species. Increased fecundity may be associated with flightlessness, although nutritional studies comparing numbers of eggs produced in relation to female pupal weight for species with flighted and flightless females must be performed to evaluate this assertion.