Two-spotted longhorn bee

Two-spotted longhorn bee is a hairy, black, moderately large bee. It occurs in the United States from Maine west to eastern North Dakota and Colorado, and south to northern Florida and eastern Texas. Adults are active in late summer and fall when their preferred plants are in bloom. They feed on pollen from a wide variety of flowers in several plant families.

The female is ½″ to ⅝″ (13 to 15 mm) in length. The hairs on the head are entirely black. The plate on the face above the upper lip (clypeus) is entirely black and unlobed. Each lateral margin of the clypeus touches the adjacent compound eye. The finger-like sensory appendages (palps) on the “under-jaws” (maxillae) have four segments. The antennae are black above, pale on the underside. They have 12 segments, a long scape at the base, a short pedicel, and a whip-like section (flagellum) with 10 segments (flagellomeres). The first flagellomere is much shorter than the second.

The body is robust and nearly all black. The thorax and abdomen are densely covered with relatively long and more or less erect hairs. On the thorax the hairs are entirely black. On the abdomen the hairs are mostly black. There are sometimes a few white hairs on the extreme sides of segments 2 and 3. Segment 4 has a dense band of white hairs at the tip that is broadly interrupted in the middle, appearing as two bright white spots. This is the feature that gives the bee both its species epithet and its common name.

The legs are black and are covered with black hairs. The fourth segment (tibia) on the hind legs has a pale, feather-like (plumose) tuft of pollen-collecting hairs (scopa). The last part of the leg (tarsus), corresponding to the foot, has five segments.

The wings are uniformly tinged brownish and have brownish-black or black veins. There are three submarginal cells on the forewing. The second cell is shorter than first and third cells. The third cell is much longer than wide.

The male is smaller, 7⁄16″ to ½″ (11 to 13 mm) in length. The antennae have 13 segments and are much longer. The clypeus is entirely yellow. There are white bands of hairs on segments 3, 4, and 5 that are very broadly interrupted in the middle. The hairs on segment 5 are much less dense then those on segment 4 of the female, and do not appear as bright white spots. There is a pair of robust spines at the base of the segment 7. The hairs on the tibia and the first tarsal segment (basitarsus) of the middle and hind legs are white. There is no scopa on the hind legs.

Male: 7⁄16″ to ½″ (11 to 13 mm)

Female: ½″ to ⅝″ (13 to 15 mm)

Late summer and fall

Pollen and nectar in the nest

Pollen of a wide variety of flowers in several plant families

Larvae are of Melissodes bimaculatus are parasitized by lunate longhorn-cuckoo (Triepeolus lunatus). his cuckoo bee is a cleptoparasite, meaning its larvae consume the pollen and nectar provisions gathered by the host bee for its own offspring, often after killing the host egg or larva.

Black Long-horned Bee (Apidae: Melissodes bimaculata)
Carl Barrentine

Black Long-horned Bee (Apidae: Melissodes bimaculata) on Leaf
Carl Barrentine

Melissodes bimaculatus grooming
Amy Schnebelin

Two-spotted Long-horned Bee (Melissodes bimaculata) closeup on Spotted beebalm (Monarda punctata)
Tom Wassmer

Melissodes bimaculatus
Michael Stockman