Seasonal Dynamics of the American Burying Beetle (Nicrophorus Americanus) in Eastern Oklahoma

Abstract

American Burying Beetle (ABB) (Nicrophorus americanus) populations have been in decline since the early 1900's, and much effort has been put into studying the survival of this now endangered species. Burying beetles (Coleoptera:Silphidae), which rely solely on carrion as both a reproductive and food resource, exclude most other competitors by burying small mammal and other vertebrate carcasses underground. Fertilized females may reproduce alone or in groups, but a carcass is usually buried by a male and female pair. Small carrion are a short-lived, high-quality resource for many insects. The competition for this valuable resource is strong and has probably shaped many ecological, behavioral, and physiological traits of the associated insects. Not only do the burying beetles compete with other insects, they must also compete with vertebrate scavengers. In southeastern Oklahoma, the ABB compete directly or indirectly with many other insect species. I completed 2273 trap-nights using above-ground pitfall traps that were placed in three separate areas within Pittsburg and Hughes counties in southeastern Oklahoma. After two years of sampling in this region, the four most abundant insect species trapped in conjunction with the ABB were the red-lined carrion beetle Necrodes surinamensis, the congener Nicrophorus orbicollis, the ridged carrion beetle Oiceoptoma inaequale, and the beetle Euspilotus assimilis from the Family Histeridae. Whole-season trap-catch data revealed significant overlap among these species and suggests that intraspecific competition may play an important role in local ABB persistence.