Colony distribution and prey diversity of Cerceris fumipennis (Hymenoptera, Crabronidae) in British Columbia

Abstract

Cercerisfumipennis Say, 1837 (Hymenoptera: Crabronidae) is a wasp that provisions its subterranean nests with jewel beetles (Coleoptera: Buprestidae). At 3 newly discovered colonies in British Columbia (BC), Cercerisfumipennis prey were collected by excavating the subterranean nests, using sweep nets to capture paralyzed prey in the grasp of a female returning to her nest, or collecting prey discarded at the nest entrance. In total, 9 species were collected: Acmaeoderaidahoensis Barr, Agriluscrataegi Frost, Agrilusgranulatuspopuli Fisher, Anthaxia (Haplanthaxia) caseyicaseyi Obenberger, Chrysobothrislaricis Van Dyke, Chrysobothrisleechi Barr, Phaenopsdrummondi (Kirby), Phaenopsgentilis (LeConte) and Phaenopsintrusa (Horn). Anthaxiacaseyicaseyi was the smallest beetle (4.2 mm) while Chrysobothrisleechi was the largest (12.0 mm). The average size of all buprestid prey taken by females from all 3 colonies was 8.8 mm. These represent the first prey records for Cercerisfumipennis in BC and with the exception of Phaenopsdrummondi are new prey records for this wasp. A single Harpalusaffinis (Schrank) (Coleoptera: Carabidae) was discovered within a brood cell containing Acmaeodera spp. elytra, but it is unclear if this beetle was placed in the cell by a female wasp.