Sculptured resin bee (Megachile sculpturalis)

Megachilidae > Megachile > Megachile sculpturalis

Even to the novice observer, sculptured resin bee (Megachile sculpturalis) is hard to miss. These large, loud, exotic megachilids hardly are closer in size to a small dragonfly than to most other bees in the region. It has been highly successful in human-disturbed landscapes, where it’s drawn to numerous ornamental flowers, including the widely cultivated butterfly bush (Buddleja). This species has greatly expanded its global range in recent years following several cases of accidental introduction.

Phenology

Summer, one generation per year. In Massachusetts, July through mid-September.

Range

Widespread and common throughout northeast, especially in cultivated and urban areas. In recent years, has spread north into northern Vermont, Maine, and southern Canada. Globally, spreading rapidly following introduction to North America in 1994 and to Europe in 2008.

Appearance

Size >> honey bee (about the size of Xylocopa virginica)

Females are massive, elongate bees, with a rough integument, brown thorax hairs, brown hair on T1, and black integument T2-T6. Smoky wings held out while foraging.

Males like females, but slightly smaller, and with brown hairs covering clypeus.

Similar species

Unmistakable among Megachile in the region.

Xylocopa virginica has stockier, wider body and glossy, not matte/rough integument on abdomen.

Nesting

Above-ground cavities in a variety of structures, including bee hotels. Nests are lined with tree resin. Known to usurp Xylocopa from nest galleries in search of suitable cavities.

Foraging

Generalized, visiting plants from a wide diversity of families including Asteraceae and Lamiaceae. In cultivated landscapes, regularly found on butterfly bush Buddleja sp.

Natural Enemies

No known nest predators in North America.

References

Laport, R.G, and R.L. Minckley. 2012. Occupation of active Xylocopa virginica nests by the recently invasive Megachile sculpturalis in Upstate New York. J. Kans. Entomol. Soc. 85: 384–86. 

Past last updated:
January 17, 2023