The effects of forest fragmentation on parasitoids of the forest tent caterpillar (Malacosoma disstria)

The forest tent caterpillar (Malacosoma disstria, (Hubner)) is a cyclic defoliator of trembling aspen (Populus tremuloides) found throughout most of North America. The cyclic dynamics of this species are believed to be linked to parasitoids. In this study I experimentally elevate FTC density in both forest fragments and continuous forest and examine resultant parasitism to gain insight into the effect of fragmentation on parasitoid movement. I also examine the effects of forest fragmentation on the structure of the late larval FTC tachinid parasitoid community.; For most species, parasitism rates did not differ significantly between forest fragments and continuous forest, for the remainder, parasitism was higher in fragments. There was no effect of isolation distance, landscape connectedness, nor patch size on parasitism. Forest fragmentation did affect the relative abundance of FTC parasitoid species, however, parasitoid communities in individual forest fragments were similar to that found in continuous forest.