Acorn Weevil (Coleoptera: Curculionidae) Predation Dynamics in a Mississippi Bottomland Hardwood Forest

Abstract

ABSTRACT Curculio and Conotrachelus weevils (Coleoptera: Curculionidae) can render the majority of North American Quercus spp. acorn crops nonviable, thereby reducing food resources for wildlife and limiting opportunities for seedling establishment. Acorn predation by weevils at the individual tree level can be influenced by many factors, and research specifically investigating acorn predation by weevils in seasonally flooded bottomland oak forests is lacking. We placed cone emergence traps in a periodically flooded forest on the Sam D. Hamilton Noxubee National Wildlife Refuge near Brooksville, Mississippi to obtain weevil population parameter estimates, record emergence phenologies, and identify variables that may aid in understanding tree-to-tree variability in acorn predation rates. Forty-three Curculio weevils representing five species emerged from mid-August through early November, and 56% of those captured emerged over an 11-day period in mid-September. Sixty-four Conotrachelus weevils representing two species emerged from mid-August through late November and occurred at nearly twice the density of Curculio weevils. The exotic Asiatic oak weevil, Crytepistomus castaneus, a minor defoliator, emerged from August through early November. We also identified Quercus density, specifically the proportion of oaks that immediately neighbor the host tree, as a potentially important explanatory variable of acorn predation by weevils at the tree level in bottomland forest habitats.