Oviposition preference and larval performance of Lymantria dispar in northern Michigan.

Abstract

This experiment tested female ovipositing preference and first instar larval performance of Lymantria dispar on eight host tree species in northern Michigan. Larvae were distributed proportionally on tree branches of the host tree species; after thirteen days, their growth was measured. Egg masses in the study site were counted to determine if a preference was shown for oviposition sites. Nitrogen and water analyses were performed on each of the eight tree species and a correlation was found between water and nitrogen levels, when considered together, and larval growth. A female oviposition preference was found for bigtooth, beech, and sugar maple. Comparisons were made to determine differences in growth between larvae on the same tree species and between different tree species. Larval growth was highest on red oak and bigtooth aspen, while larvae performed poorly on hemlock, white pine, and red maple. Larval performance was compared against female ovipositioning and no correlation was found.