Texas leaf-cutter bee

Texas leaf-cutter bee is a chunky-looking, moderate-sized, solitary, leaf-cutting bee. It is common and widespread across the United States, in adjacent Canadian provinces, and in Mexico. It is uncommon, or at least little reported, in Minnesota.

Females are robust and 7 ⁄16″ to 9 ⁄16″ (11 to 14 mm) long. The head is matte black. There are two large compound eyes, one on each side of the head; and three small simple eyes (ocelli) in a triangular pattern at the top of the head between the compound eyes. The area behind and below each compound eye (gena) is narrower than the compound eye. The sides of the face (paraocular area) and the area at the base of the antennae are densely covered with short whitish hairs. The gena is also covered with whitish hairs, dense and short at the bottom, becoming sparser and shorter toward the top. The top of the head (vertex) is covered with black hairs. The mandibles have 4 teeth and are very large, sometimes described as “enormous”. The large size allows them to be used for chewing leaves, gnawing wood, and moving small stones. The tongue is long and slender. The antennae are thread-like and are not elbowed. They have 12 segments.

The thorax (mesosoma) has three segments. However, the first segment of the abdomen is fused to the thorax, giving the thorax the appearance of having four segments. The upper side of the thorax is matte black and densely pitted. It is covered with short, whitish hairs at the front and sides, black hairs on most of the middle, and some whitish hairs at the rear. The small plate covering the base of each forewing (tegula) is black.

The abdomen is matte black and densely and finely pitted. There are six hardened plates (tergites) on the upper (dorsal) portion of the abdomen. The second through fifth tergites (T2 through T5) have a narrow, very dense fringe of short, whitish, rear-facing hairs, giving the abdomen a narrowly striped appearance. T1 is similar but mostly pale and some black hairs. T6 is distinctly concave when viewed from the side. The underside of the abdomen is densely covered with long, branched, electrostatically charged hairs (scopa) used for collecting pollen. On the female, the scopa are entirely yellowish-white on segments 2 through 4, yellowish-white at the base with black tips on segment 5, and entirely black on segment 6.

The wings are semitransparent and have black veins. The broad lobe at the base of the hindwing (jugal lobe) is shorter than the narrow lobe adjacent to it (submedian lobe).

The legs are black. Unlike most bees, there are no scopa on the hind legs. The last part of the leg (tarsus), beyond the fourth segment (tibia) and corresponding to the foot, has three sections. On the middle and hind legs the first section (basitarsus) is nearly as long and broad as the tibia.

Males are a little smaller than females, ⅜″ to ½″ (10 to 12 mm) long. The mandibles have only 3 teeth. The hairs on the lower part of the gena are snowy-white, longer, and more abundant than on the female. The fringe of whitish hairs on T1 through T5 is dense at the sides, becoming shorter, sparser, and interrupted in the middle. The basitarsus on all legs is slender and shorter than the tibia.

Male: ⅜″ to ½″ (10 to 12 mm)

Female: 7 ⁄16″ to 9 ⁄16″ (11 to 14 mm)

Texas leaf-cutter bee is a solitary bee. It does not nest in hives. The female builds a tubular nest, usually in an existing crevice, often near other nests but never sharing an entrance. She cuts circular disks of leaves, about 1″ in diameter, placing about 15 of them at the bottom of the first cell. She then provisions the cell with pollen and regurgitated nectar, and lays a single egg. She then seals the cell with more leaf disks. She continues this process until she has laid 18 to 25 or more eggs. The larvae undergo four instar stages. Some will emerge as adults later in the summer. Others will enter a pre-pupal, hibernation-like phase (diapause), overwinter, pupate in the spring, and emerge as adults the following summer.

Flower nectar and pollen

Texas leaf-cutter bee is a food generalist. It eats pollen and nectar from more than 80 different species of plants.

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