Biology of Trypoxylon in Trap Nests in Wisconsin (Hymenoptera: Sphecidae)

Publisher Website
Google Scholar
Abstract
Four spp. of Trypoxylon were collected in sumac trap nests in Wisconsin: T. frigidum Smith, rubrocinctum Packard, striatum Provancher, and tridentatum Packard, the latter being found in one nest only. Nests of each species consisted of a linear series of cells constructed in borings of 3/16-, 1/4- and 5/16-in. diameter. The average number of cells in nests of T. frigidum and rubrocinctum was about 6. Nests of T. striatum averaged 5 cells, as the cells were longer. The mother wasp provisioned a cell with spiders, laid an egg on the abdomen of 1 of the last spiders introduced, and sealed the cell with a wall of clay, thus providing a microcosm with shelter and food for each of the progeny. A variety of spiders was utilized as prey; most nests contained at least 3 spp., 2 genera and 2 families. Theridiid spiders were preferred by T. rubrocinctum, whereas striatum relied mostly on Araneidae. The amount of food in cells was determined primarily on a weight basis. The period of larval growth was about one week. After the larva spun a cocoon, most of the remaining period in the univoltine life cycle of T. rubrocinctum and striatum was passed as a prepupa in diapause. T. frigidum had a summer and winter generation, with the summer generation requiring about 1 mo. Reared adults were associated with cell location in the nest, and no consistent pattern of sequences of sexes was shown. The nests were parasitized infrequently by Chrysis verticalis Patton, C. pellucidula Aaron, Melittobia chalybii Ashmead, and miltogrammine sarcophagids in the genera Amobia and Senotaenia.

This publication has 3 references indexed in Scilit: