Browsing by Author "Hall, H. Glenn."
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Item Nest site selection and nesting behavior of the bee Lithurgopsis apicalis (Megachilidae, Lithurginae). (American Museum novitates, no. 3796)(American Museum of Natural History., 2014-02-06) Rozen, Jerome G., Jr. (Jerome George), 1928-; Hall, H. Glenn.This paper reports on the biology of Lithurgopsis apicalis (Cresson) that were found excavating nests in the dead and dying flower/seed stalks of Agave in southern Arizona. Females normally gain entry to the soft inner tissue of the stalk by seeking out naturally occurring longitudinal cracks in the hard outer surface of the stalk. Once inside they chew branching tunnels through the soft plant tissue, at the end of which are one or more extremely elongate brood cells. The cells were normally found to contain one or more eggs, each in a small empty pocket entirely within the provisions of soft pollen, which completely filled the cell. The attachment of the egg to the provisions is described, as is the egg itself. The first four larval instars remain attached to the provisions while the elongate fifth (final larval) instar is free from the provisions and starts defecating while still eating the food, which gradually intermixes with fecal pellets. Toward the end of defecation, larvae start spinning strands of silk to form cocoons. After finishing spinning, larvae enter diapause, becoming quiescent over a period of more than a week. However, when in diapause, they still react to touch by curling and uncurling their bodies unlike totally quiescent diapausing larvae of most bees. Cocoon structure and function are described. Throughout the paper, aspects of nesting biology of this species are compared with those of other lithurgines. New details concerning the cocoon of Trichothurgus dubius (Sichel) are presented, and ovarian statistics for Lithurgopsis apicalis are appended.Item Nesting and developmental biology of the cleptoparasitic bee Stelis ater (Anthidiini) and its host, Osmia chalybea (Osmiini) (Hymenoptera, Megachilidae). (American Museum novitates, no. 3707)(American Museum of Natural History., 2011) Rozen, Jerome G., Jr. (Jerome George), 1928-; Hall, H. Glenn.Herein we provide the first account of the nesting biology of Osmia (Helicosmia) chalybea Smith and of its cleptoparasite Stelis (Stelis) ater Mitchell, a newly confirmed host association. The nesting behavior of O. chalybea is similar to what is known about other members of the subgenus Helicosmia, but novel information concerning egg eclosion and cocoon structure and function are reported. Eggs of S. ater were discovered both on the front surface of the host provisions as well as deeply buried in the pollen-nectar mixture. From numerous observations, larval S. ater attacks host immatures or conspecifics whenever encountered. Because young larvae are unable to crawl (perhaps a family characteristic), the hospicidal individual may be in its third to fifth stadium or even in its second stadium, although none of the latter was certainly identified. Although usually a single cleptoparasitic egg or larva was found in a cell, two or three were occasionally observed there. The cocoon of S. ater was also examined closely. Although its construction differs in a number of ways from that of the host cocoon, the functions of both seem to be the same, i.e., excluding parasitic/parasitoid arthropods and preventing desiccation while allowing exchange of air with the outside through complex filtering devices at the front ends of cocoons. Known parasites/parasitoids in the area of study include the minute parasitoid wasp Melittobia digitata Dahms (Eulophidae) and the parasitic mite Chaetodactylus rozeni Klimov and O'Connor (the latter recovered from adults of O. chalybea). The nearly airtight cocoon fabric of both bee cocoons presumably assists immatures in maintaining their water balance through their many months of confinement. Ovarian statistics for both species are presented and compared with congeners, and their eggs/mature oocytes are described. Both have five larval instars. Comparative taxonomic descriptions of last larval instars are presented, and mandibular shapes of other larval instars are diagrammed.Item Nesting biology and immatures of the oligolectic bee Trachusa larreae (Apoidea, Megachilidae, Anthidiini). (American Museum novitates, no. 3765)(American Museum of Natural History., 2012-12-19) Rozen, Jerome G., Jr. (Jerome George), 1928-; Hall, H. Glenn.Herein we report on the nesting biology of ground-nesting Trachusa (Heteranthidium) larreae (Cockerell) from New Mexico and Arizona, an oligolege of creosote bush, Larrea tridentate (DC.) Coville (Zygophyllaceae). Nests are single, slanting, open burrows at the lower end of which are horizontal cells lined with resin collected from creosote bush, also the source of the orange, mealy-moist provisions. Eggs are placed on the surface of the provisions, and the first three instars remain in the same position as the eggs from which they hatched. The fourth instar separates its body from the provisions, and only the fifth (final larval) instar moves around the brood chamber while consuming remaining provisions and defecating prior to cocoon spinning. It is suggested that mid-dorsal body tubercles and an integumental body vestiture of short setae and setiform spicules restricted to this instar are adaptations enabling the movement of the fifth instar not only of this species but possibly those of other Megachilinae, all of which have a body vestiture and presumably mid-dorsal body tubercles. The cocoon is spun after most of the feces are voided. Like cocoons of many other Megachilidae, it bears a pronounced nipple at its anterior end. From its construction as well as by comparison with cocoons of other bee taxa, the nipple seems to serve a number of functions: it enables exchange between the interior air of the cocoon and the external ambient air; it screens out parasites and predators from attacking the cocoon inhabitant; and it probably regulates cell humidity. Eggs are briefly characterized, and three females each were found to have three ovarioles per ovary and to carry a single mature oocyte, which is classified as medium in Iwata and Sakagami's classification of egg/mature oocyte size relative to body size of female. The fifth instars (both pre- and post-defecating forms) are described and found similar to those of other Anthidiini.