Nutritional, foraging, and nesting preferences of three species of solitary bees, Megachile rotundata, Megachile pugnata, and Megachile sculpturalis

There are over 1400 Megachile species in the world, and more than 140 species in North America. Little is known about the natural history of most Megachile species. We examined nutritional, foraging, and nesting preferences of three species. M. pugnata is a native species, but M. rotundata and M. sculpturalis are introduced. Each species exhibited a unique nest cavity diameter preference. M. pugnata collected pollen for brood provisions with significantly lower protein-to-lipid ratios than the other two species. The species also varied in their pollen preferences, with M. sculpturalis collecting primarily from the genus Styphnolobium, M. rotundata from the Fabaceae family, and M. pugnata from the Asteraceae family. M. rotundata and M. pugnata collected leaf material primarily from plants in the rosid clade in contrast to the plant genera visited for pollen. This study provides insight into how these species partition resources and can inform landscape design for pollinator communities.