@article {1618,
	title = {The effect of diet breadth and nesting ecology on body size variation in bees (Apiformes)},
	journal = {Journal of the Kansas Entomological Society},
	volume = {73},
	year = {2000},
	month = {2000///},
	pages = {180 - 193},
	abstract = {Body size in animals influences survival, fecundity, and mating opportunity. For bees, parental provisioning behavior largely controls offspring body size. Because larger offspring of many bee species have fitness advantages, selection on body size should act through selection on parental provisioning behavior and restrict body size variation of each species. Many bet species show great variability in body size, however, which may indicate that adult females are often constrained in their ability to consistently produce large offspring. We compared body size variation within bee species for two life history traits that could influence offspring body size: dietary breadth (specialist or generalist) and nesting habit (ground-nesting or cavity-nesting). We determined the head width (a reliable correlate of body size) of 2276 bees belonging to 31 bee species from five families and calculated the body size variation fur each species. Body size variation, measured as the coefficient of variation in head size, did not differ between pollen specialists (oligoleges) and pollen generalists (polyleges) across 13 pairs of closely-related, sympatric bee species of similar body size. Cavity-nesting species showed significantly greater variation in body size than ground-nesting species, which suggests that the choice of nest cavities utilized may be a more important predictor of offspring body size than parental body size. The cleptoparasite Coelioxys sayi had similar body size variation to one of its hosts, Megachile brevis. The European honey bee, Apis mellifera, showed the least body size variation of any species measured},
	keywords = {APIS, Apoidea, BEE SIZE, BEHAVIOR, BEHAVIOR-NESTING, CLEPTOPARASITE, ECOLOGY, FITNESS, LARVAL PROVISIONS, LIFE HISTORY, MEGACHILE, MORPHOLOGY, OLIGOLECTY, POLLEN, POLYLECTY, SELECTION, SIZE, VARIATION},
	author = {Roulston,T.H. and Cane, J. H.}
}
@article {1608,
	title = {Origins and ecological consequences of pollen specialization among desert bees},
	journal = {Proceedings of the Royal Society of London - Series B: Biological Sciences},
	volume = {267},
	year = {2000},
	month = {2000///},
	pages = {265 - 271},
	abstract = {An understanding of the evolutionary origins of insect foraging specialization is often hindered by a poor biogeographical and palaeoecological record. The historical biogeography (20 000 years before present to the present) of the desert-limited plant, creosote bush (Larrea tridentata), is remarkably complete. This history coupled with the distribution pattern of its bee fauna suggests pollen specialization For creosote bush pollen has evolved repeatedly among bees in the Lower Sonoran and Mojave deserts. In these highly xeric, floristically depauperate environments, species of specialist bees surpass generalist bees in diversity, biomass and abundance. The ability of specialist bees to facultatively remain in diapause through resource-poor years and to emerge synchronously with host plant bloom in resource-rich years probably explains their ecological dominance and persistence in these areas. Repeated origins of pollen specialization to one host plant where bloom occurs least predictably is a counter-example to prevailing theories that postulate such traits originate where the plant grows best and blooms most reliably Host-plant synchronization, a paucity of alternative floral hosts, or flowering attributes of creosote bush alone or in concert may account for the diversity of bee specialists that depend on this plant instead of nutritional factors or chemical coevolution between floral rewards and the pollinators they have evolved to attract},
	keywords = {Apoidea, BIOGEOGRAPHY, COEVOLUTION, DIAPAUSE, DIVERSITY, EVOLUTION, FLOWERING, LARREA, OLIGOLECTY, PHENOLOGY, POLLEN, POLLINATOR, SPECIATION},
	author = {Minckley,R.L. and Cane, J. H. and Kervin,L.}
}
