Extracted from 2017 “Bees of Maryland: A Field Guide” http://bio2.elmira.edu/fieldbio/beesofmarylandbookversion1.pdf
Common in the summer, particularly on tall groups of composites, where they move blindingly quickly among the flowers, particularly the males.
Field Marks: ♀♂Light colored hairs on head and thorax (all black on M. bimaculata). Abdomen, most species with thin, transverse bands of white hairs, often set back from the rim. Tibia, hairs (at least outward facing side), tan to white. ♂Clypeus all yellow. Antennae long and when pulled back surpass the base of the wings and extend to rear of thorax. Males extremely fast flying and usually only seen as a blur until they hesitate at a blossom for the tiniest moment but more easily found late in the afternoon and early evening when they are stationary on the flowers for the night. Females also fast but spend more time foraging on flowers for pollen.
Flight Season: Summer and fall.
Size Relative to Honey Bee: 1–1.5X.
Position of Wings Feeding on Flowers: Crossed on back.
Location of Pollen Carrying Hairs: Hind tarsus and basitarsus.
Similar Genera: Eucera - Has a primarily spring flight season with some overlap in June. Clypeus, strongly projecting, viewed from side clypeus is as tall, or taller, than the eye is wide, only moderately so in Melissodes. Florilegus - Abdomen, with broad white hair bands on the 4th and 5th segment separated by black, this pattern can be seen from quite a distance. Svastra - Larger (approaching Carpenter Bees in size, most Melissodes approach Honey Bees in size), comparatively flatter clypeus, less common. ♀One species has all black hairs on hind tibia (S. atripes), one species with extensive black hair on body (S. obliqua) with hind tibia hairs orange to burnt orange and basitarsus hairs black to brown, remaining species (S. compta), rare, likely to only be seen on evening primrose (Oenothera spp.) early in the morning or in the evening but otherwise indistinguishable other than by size. ♂Antennae not quite as long, reaching to only about the base of the wings. Other Eucerines (Squash Bee Group) - On the larger end of the range of Melissodes species. All are specialists, restrict their foraging almost entirely to squash (Cucurbita spp.) or morning-glories (Ipomoea spp.), and forage only very early morning, males with restricted yellow on clypeus and antennae that only reach wing bases.
Flowers: Almost entirely composites with specialists on sunflower (Helianthus spp.), thistle (Helianthus spp.), ironweed (Vernonia spp.) and one rare Pickerelweed (Pontederia cordata) specialist.
- David L. Green