@article { ISI:000246496000008,
	title = {The male of Megachile nivalis Friese, with an updated key to members of the subgenus Megachile s. str. (Hymenoptera : Megachilidae) in North America},
	journal = {JOURNAL OF HYMENOPTERA RESEARCH},
	volume = {16},
	number = {{1}},
	year = {2007},
	pages = {178-191},
	abstract = {{The previously unknown male of Megachile nivalis Friese is described. Males of this species are very similar to those of M. relativa Cresson and because of geographic overlap of the two species, many male specimens presently identified as M. relativa within collections may actually be M. nivalis. An identification key and illustrations of mandibles are provided for females and males of the subgenus Megachile s. str. of North America. Images of genitalia, selected sterna, the lower genal area, clypeus, and forewings for males of both M. relativa and M. nivalis are also provided for comparison and to facilitate differentiation of the two species. A tabular summary is also provided for species of Megachile in North America that are known from only one sex to encourage the search for possible additional synonyms or hitherto unknown sexes.}},
	issn = {1070-9428},
	author = {Sheffield, Cory S. and Westby, Sue M.}
}
@article { ISI:000255098000011,
	title = {Diversity of cavity-nesting bees (Hymenoptera : Apoidea) within apple orchards and wild habitats in the Annapolis Valley, Nova Scotia, Canada},
	journal = {CANADIAN ENTOMOLOGIST},
	volume = {140},
	number = {{2}},
	year = {2007},
	month = {MAR-APR},
	pages = {235-249},
	abstract = {Solitary cavity-nesting bees, especially trap-nesting Megachilidae, have great potential as commercial pollinators. A few species have been developed for crop pollination, but the diversity, abundance, and potential pollination contributions of native cavity-nesting bees within agricultural systems have seldom been assessed. Our objectives were to compare the diversity and fecundity of cavity-nesting bees in Nova Scotia in natural ecosystems with those in apple orchards under three levels of management, using trap nests, and to determine whether any native bees show promise for development as pollinators. Our results show that species richness and numbers of bees reared from trap nests in commercially managed orchards, abandoned orchards, and natural habitats were similar, and species{\textquoteright} compositional patterns were not unique to specific habitats. Trap nests can be used to increase and maintain cavity-nesting bee populations within Nova Scotia apple orchards. Osmia tersula Cockerell (Megachilidae), which accounted for almost 45\% of all bees captured and was the most abundant species nesting in all habitats evaluated, should be assessed for potential as a commercial pollinator of spring-flowering crops. The influence of natural cavities on bee species richness in trap-nesting surveys is also discussed.},
	issn = {0008-347X},
	author = {Sheffield, Cory S. and Kevan, Peter G. and Westby, Sue M. and Smith, Robert F.}
}
