Cavity-Nesting Wasps and Bees of Central New York State: The Montezuma Wetlands Complex

Abstract

Solitary nest-provisioning wasps and bees in North America include species that naturally construct nests within existing cavities, such as hollow plant stems or tunnels left by wood-boring insects. The materials used to construct brood cells within nest cavities and the types of food provisions provided to offspring vary considerably among species. Over five summers (2001-2002, 2005-2007), we used trap nests to survey the cavity-nesting wasp and bee assemblage within the Montezuma Wetlands Complex in central New York State. Over 350 trap nests were occupied by 6 species of apoid wasps (Sphecidae, Crabronidae; 34% of nests), 7 vespid wasps (Vespidae: Eumeninae; 39%), 2 spider wasps (Pompilidae; 3%), and 12 bees (Megachilidae, Colletidae; 26%), as well as brood parasites and parasitoids of the nest provisioners. The most common nest-provisioning wasp was Trypoxylon lactitarse, followed by Ancistrocerus antilope, Isodontia mexicana, Symmorphus canadensis, Symmorphus cristatus, and Euodynerus foraminatus. The only two bee species with comparable incidences were Hylaeus annulatus and Heriades cari- natus. Natural enemies emerging from nests included at least 17 species from 10 families, the most common of which were brood-parasitic cuckoo wasps (7 species of Chrysididae; 39 nests) and flies (Sarcophagidae; 11 nests). We also report brood sex ratios of the seven most abundant species, finding them to be either male-biased (A. antilope, T. lactitarse), female-biased (E. foraminatus), or not significantly dif- ferent from unity. We compare our survey results to others done in north-central and eastern North America.