A Comparison of Trap Versus Ground Collection of Acorns to Assess Insect Infestation
Oak (Quercus spp.) species are a significant portion of the forest in the Eastern United States. Oaks provide valuable timber products and habitat for many wildlife species. Acorns are essential for oak regeneration and are a major food source for more than 186 species of birds and mammals. Great variation in annual acorn production causes dramatic fluctuations in seed availability for food and oak regeneration. Although total annual production may have the greatest effect on acorn abundance, availability can be dramatically reduced by insects. During years of high production, insect losses are usually low in proportion to abundance; however, insects can destroy most acorns during years of low production. Loss of acorns to insects can vary from as low as 6 percent to more than 80 percent. Thus, studies seeking information on oak regeneration and studies involving wildlife food availability may be biased when insect predation is not considered. To provide information on acorn abundance and loss to insects, most studies have used acorns collected from traps. However, traps are costly to build and maintain, require many hours to install, and provide limited sampling areas and high variance. Collecting acorns from the ground is a quick and inexpensive method of obtaining large samples of acorns. Given the high costs associated with trapping acorns, the authors tested whether insect infestation level differed according to collection method to determine whether collecting acorns from the ground is a viable alternative to trapping.