Andrenidae > Andrena > Andrena carlini / Andrena regularis

It wouldn’t be spring without spotting Carlin’s and Regular mining bees (Andrena carlini / Andrena regularis). Look for a large, fuzzy Andrena that resembles a small bumble bee: black abdomen, tan thorax, and dark sides of the thorax. Both members of this species pair are important crop pollinators of apples and blueberries in the region, though Andrena regularis is less common and restricted to northern latitudes (or higher elevations further south).

Phenology

March through May, with records from northern Maine extending into June. One generation per year.

Range

Widespread throughout northeast. Andrena regularis is restricted to northerly latitudes, whereas Andrena carlini is found throughout the entire northeast.

Appearance

Size ≥ honey bee

Females are large, stocky Andrena with all black abdomen, tan thorax with thick even hairs, dark sides to the thorax, black cheeks, and a black face with some pale hairs. Dark scopal hairs. From close-up photos or examination with a hand lens, A. carlini often has a vertical ridge down the center of the face, whereas A. regularis does not.

Males are smaller and more slender than females with a densely hairy face, tan thorax, and black abdomen with thin messy hairs on edges. Male A. carlini are unique among male Melandrena for the black hairs on the inner margin of the eyes.

Similar species

• Andrena carlini and Andrena regularis are difficult to separate from one another in the field.
• Andrena vicina is similar but has tan/light-colored cheeks and a protruding clypeus. Thorax of A. vicina averages browner than A. carlini/regularis.

Nesting

Andrena carlini nests singly with nests often found far from one another. Burrow entrances may or may not be obscured by vegetations  Single nests are sometimes found within aggregations of other spring-active species like Colletes inaequalis.

Andrena regularis is known to nest gregariously on hard-packed ground in forested areas and in blueberry barrens. A. regularis nesting appears to benefit from frequent burning of blueberry barrens for cultivation. Nests may have large tumuli and are left open during foraging bouts.

Foraging

Generalized. Both species commonly forage on spring-blooming shrubs including willows (Salix spp.), apples (Malus spp.), fire cherry (Prunus pensylvanica), chokeberry (Aronia melanocarpa), and serviceberry (Amelanchier), and blueberry (Vaccinium spp.).

A. carlini is also known to forage on several weedy taxa of common plants in disturbed areas and suburban yards forages on many including rocket cress (Barbarea vulgaris), bittercress (Cardamine spp.), dandelion (Taraxacum officinale), and white clover (Trifolium repens).

Natural enemies

• Nomada luteoloides is likely a parasite of A. carlini.
• Nomada imbricata parasitizes A. regularis. Anthomyiid flies Leucophora shadow A. regularis back to nests and anthomyiid larvae have been recovered from A. regularis brood cells.

References

Schrader, M.N. and LaBerge, W.E. 1978. The nest biology of the bees Andrena (Melandrena) regularis Malloch and Andrena (Melandrena) carlini Cockerell (Hymenoptera: Andrenidae). Illinois Natural History Survey. Biological Notes No. 108.

Page last updated: February 22, 2023