Distribution of Carrion Beetles (Coleoptera: Silphidae) in Different Geographic Regions of Virginia

Abstract

The distribution of beetles in the Family Silphidae has not been well studied in Virginia. The primary purpose of this study was to survey silphid beetles in a more systematic manner across different geographic regions of the state, with a special consideration for Nicrophorus species. The seasonal abundance and diversity of silphid beetles in Montgomery County, Virginia, was also examined. Baited pitfall traps were used to sample beetle distribution and abundance, and were placed in each of the five geographical regions of Virginia in the summers of 2007 and 2008. Traps were placed approximately one kilometer apart and were checked daily over a five day period for each of three sampling periods. A total of 4375 silphid beetles, consisting of 11 species in four genera, were collected in ten counties with beetles in the subfamily Silphinae being predominant. Within the Nicrophorinae, Nicrophorus tomentosus and N. orbicollis were dominant in 2007; whereas in the summer of 2008, N. tomentosus and N. pustulatus were the most commonly collected. Contingency analyses indicated that species abundance was associated with sampling period and geographic region. Nicrophorus americanus was not collected during either summer of surveying and only three N. carolinus were trapped in Suffolk County in the summer of 2008. For the Montgomery County survey, a total of 3276 beetles were found between the middle of April and the middle of October. The prevalent species within Nicrophorinae was Nicrophorus tomentosus and within the Silphinae it was Necrophila americana. Species abundance was associated with sampling period.