Extracted from 2017 “Bees of Maryland: A Field Guide” http://bio2.elmira.edu/fieldbio/beesofmarylandbookversion1.pdf
Small, overlooked, and rarely detected spring species; but likely more commonly
detected if people looked for nest sites and observed bees at each species’ favorite
Field Marks: ♀♂Small size. Hair, largely absent. Face, wider than long.
Wings, while often difficult to see, these species have only 2 submarginal cells.
Abdomen, no pale hair bands/patches or pale markings of any kind. ♀Integument,
including face, entirely black. Note: face has narrow slits (foveae) above antennae
parallel to compound eye, but these are difficult to see without a microscope or
high-res photograph. ♂Clypeus bright yellow or mostly bright yellow, remainder
of bee all black, with the exception of the ends of the legs (tarsal segments) and
portions of front tibia with pale markings.
Flight Season: Spring
Size Relative to Honey Bee: 0.5X
Position of Wings Feeding on Flowers: Completely overlapping
Location of Pollen Carrying Hairs: Hind tibia and basitarsus
Similar Genera: Hylaeus - ♀Face, yellow/white markings between eye and
clypeus. Carries no external pollen. ♂Face, entire lower face often yellow/palewhite.
Calliopsis - Markings quite different. Pseudopanurgus and Perdita - Flight
periods do not overlap, both out only in the fall. Most of the Other Genera that are
Small Black Bees - Have 3 submarginal cells and noticeable, though possibly
restricted, patches/bands of pale hairs.
Nest: Ground, flat, open bare soil. P. polytrichus and P. potentillae are known
to aggregate their nests.
Flowers: Forbs and low shrubs