Factors Associated With Diversity and Distribution of Buprestid Prey Captured by ForagingCerceris fumipennis(Hymenoptera: Crabronidae)

Abstract

Many jewel beetles (Coleoptera: Buprestidae) play an important ecological role in wood decomposition and nutrient cycling. Compared with other saproxylic species, buprestids are considered cryptic as they are difficult to sample and identify. As a result, factors that influence buprestid diversity and distribution are poorly understood. This is especially true in urban forests, which may be uniquely fragmented and contain unique species distributions. We utilized the native ground nesting hunting wasp Cerceris fumipennis Say to survey buprestids at 20 urban sites in Minnesota. We collected a total of 1,939 beetles consisting of 11 genera and 51 species, including 9 new state records for the state of Minnesota. We found a positive relationship between wasp size and size of beetle prey captured. Agrilus was the most common genus collected, followed by Dicerca. Species richness tended to decrease in sites with many emerald ash borers, Agrilus planipennis Fairmaire, which may reflect a potential tendency of wasps to return preferentially to high-density infestations of emerald ash borers. We found buprestid species richness positively correlated with site-level variables such as the number of dead trees within a 200 m radius around each C. fumipennis nesting site. Our work illustrates how C. fumipennis can be utilized for general buprestid surveys in urban areas to better understand the distribution of this cryptic family.