FEMALE FORAGING AND INTRANEST BEHAVIOR OF A COMMUNAL BEE, PERDITA-PORTALIS (HYMENOPTERA, ANDRENIDAE)

Female Perdita portalis Timberlake are ground-nesting, partially bivoltine, communal bees that inhabit the deserts and arid grasslands of Arizona, New Mexico, and northern Mexico. From 2 to 29 adult females may share a single nest. Nests are commonly reused from year to year and may become very large, with > 200 overwintering prepupae, although some new nests are started each year. By constructing artificial, below-ground observation nests, it was possible to observe the details of cell provisioning and of female (and male) nestmate interactions within the nest. The details of cell construction, pollen collection, pollen ball formation, and oviposition are described. There was no evidence of cooperation among female nestmates or reproductive division of labor, nor was there any indication of intraspecific cleptoparasitism. The behavior of female P. portalis is compared with the behavior of females in other species of Perdita and with what is known of the intranest behavior of other bees.