This paper describes the extensive nesting site and the nesting behavior of a large population of the solitary, ground-nesting bee Epicharis (Epicharoides) albofasciata Smith, found in Trinidad in association with its cleptoparasite Mesoplia (Mesoplia) rufipes (Perty). In addition to describing nests and their cells, it provides information about provisioning, egg deposition, and larval eclosion.While pursuing an investigation comparing the larval anatomy of Centris (Heterocentris) bicornuta Mocsáry with that of Epicharis (Epicharoides) albofasciata Smith, I became aware that nothing had been reported on the nesting biology of that species of Epicharis. These two species belonging to related genera had been selected for study because of the large series of specimens of all life stages of both that have been amassed in the American Museum of Natural History. On examining my old field notes, diagrams, and Kodachrome 35 mm transparencies, I recovered extensive information related to nesting biology associated with the specimens of E. albofasciata used in that investigation. I present this information here and also interpret it in light of recent studies regarding larval eclosion in solitary apids.These notes were written on a fieldtrip to Trinidad in 1968 following three previous annual field trips there.

Announced herein is the discovery of a nesting site of Lithurgus (Lithurgus) chrysurus Fonscolombe (Megachilidae: Megachilinae: Lithurgini), an adventive solitary bee of Western Palearctic origin that had first been detected in north America in the mid-1970's and thought to have become extinct locally since then. The occurrence of the new nesting site in eastern Pennsylvania, close to the point of first discovery in new Jersey, suggests its persistent but low presence over the past 35 years. Several previous papers offered insight into nests of this species, which bores into dead wood to nest, and described its larva and pupa. The current investigation reveals new information concerning nest architecture, nest closure, its cocoon structure and functions, and anatomy of its mature larva. Its larva is compared with that of L. (Lithurgopsis) apicalis Cresson (a congener in another subgenus) and with that of Trachusa larreae (Cockerell) with consideration of how body vestiture and anatomy function to permit mature megachilid larvae to move in the confines of their brood cells.

This paper describes the eggs/mature oocytes (including ovarian statistics), mature larvae, and pupae of bees belonging to the Exomalopsini, furthering our understanding of the ana tomical and behavioral diversity of included taxa. The mature larva is the life stage best rep resented with the following treated:

A nest of the leaf-cutter bee Notanthidium (Allanthidium) chilense (Urban) (Anthidiini) is described and illustrated, the second such account for the genus. The nest, presumably constructed from resin, consisted of four cells and was attached to a stem of the plant genus Baccharis (Asteraceae) in the high Andes of northern Chile. The cells held two postdefecating larvae, a male pupa, and an emerged adult female, all in cocoons, permitting the first descriptions of the immature stages and cocoon for the genus. To the extent possible the immatures are compared with those of other tribal members.

Herein is presented nesting information on the communal ground-nesting Argentinian bees Rhophitulus xenopalpus ramos and R. mimus ramos, which is compared with what is known concerning the closely related Brazilian bee Cephalurgus anomalus moure and Lucas de oliveira. The mature larvae of all three taxa are described, illustrated, and compared with one another and with those of other Protandrenini. While larvae of the three species share many similarities, those of R. xenopalpus and R. mimus, though each distinctive, are quite similar, and those of C. anomalus differ from the others in mandibular features and in dorsal body ornamentation. male and female pupae of R. xenopalpus are also described.