Forest Management and Curculionid Weevil Diversity in Mixed Oak Forests of Southeastern Ohio

Weevils (Coleoptera: Curculionidae) may play a role in the reduced regenerative ability of oak (Quercus L.) species in the hardwood forests of eastern North America. Presently, because of biome-wide regeneration failure, silvicultural treatments of prescribed fire and mechanical thinning are being implemented as a means to enhance natural oak regeneration. The effect that these treatments may have on the diversity and population structure of non-target organisms like weevils (oak seed predators) remains unclear. This study provides an evaluation of the weevil populations of two experimentally managed, mixed-oak forests in southeastern Ohio. Each of the two sites used in this study was divided into four 20 ha treatment plots consisting of: (1) untreated control, (2) thin only, (3) thinning followed by prescribed burning, and (4) prescribed burning only plots. Pyramid style traps (N = 48) were placed in each treatment unit to sample weevils. Overall, we identified 26 species of Curculionid weevils representing nine genera from five different tribes and two subfamilies. Weevil communities were generally dominated by a few highly abundant species and a moderate number of uncommon to rare species. Generally, treatments increased overall weevil diversity and influenced the abundance of certain rare species. However, there was no significant effect on number of weevils or on occurrence of the two major acorn infesting genera (Curculio L. and Conotrachelus Dejean). Based upon our findings, prescribed spring burning had little effect on overall weevil populations and is not likely to substantively aid in silvicultural endeavors to promote oak regeneration; however, effects on rare species need to be carefully considered.