small carpenter bees

Ceratina is a genus of common, tiny to medium-sized bees called small carpenter bees. Despite that common name, Ceratina are not closely related to large carpenter bees (Xylocopa spp.). Ceratina is a cosmopolitan genus, occurring on every continent except Antarctica. There are 351 species in 22 subgenera worldwide, 24 species in 4 subgenera in North America north of Mexico, and at least 2 species in 1 subgenus in Minnesota.

Ceratina nest in dead broken twigs of bushes because they are unable to chew through the tough outer surface of intact branches. Instead, they chew through the soft inner core (pith), creating a long narrow tunnel.

Although they are generalist feeders, each species has carved out a niche, allowing up to five species to nest in close proximity without competing for resources.

All bees can produce male offspring without mating. Some Ceratina species are capable of producing female offspring without mating. Among bees, this feature is unique to this genus.

Ceratina are ¼″ to 5⁄16″ (6 to 8 mm) long, relatively robust, dull, and black, metallic blue, or metallic bluish-green. They are inconspicuously hairy, but the hairs cannot be seen without magnification.

The plate on the face (clypeus) almost always has a conspicuous, oblong, white, ivory, or yellowish mark. The mark on the male is larger and in the shape of an inverted T. The antennae are black above, brownish below.

The thorax slopes downward gradually toward the rear. On the side of the thorax, the lobe on the rear margin of the pronotum (pronotal lobe, called by some the tubercle) is white, ivory, or yellowish.

The abdomen is straight and more or less parallel on the sides then abruptly tapered at the rear. It has broad rounded ridges, somewhat like a water bottle. There are no pale markings or pale hair bands.

On the forewing, the basal vein is distinctly arched. The second submarginal cell is about as high as the base is wide. On the hindwing the rear lobe at the base (jugal lobe) is short.

The legs have sparse pollen hairs. Spurs on the legs are pale yellow.

Sources

4, 24, 27, 29, 30, 82.

I believe this is a Small Carpenter Bee.

Too small to be a sweat bee (@ 1/4 inch). Plus it stung my cat that thought he was investigating a tiny jumping spider! Carpenters are more likely to sting than sweat bees.

Location: New Prague, MN

I believe this is a Small Carpenter Bee. Too small to be a sweat bee (@ 1/4 inch). Plus it stung my cat that thought he was investigating a tiny jumping spider! Carpenters are more likely to sting than sweat bees.

Location: Woodbury, Minnesota