Giant Resin Bee

The giant resin bee (Megachile sculpturalis) is so named because it is larger than most other leafcutter bees, ranging in size from 14 to 24 mm long, and because it uses its strong jaws to collect plant resin to seal the cells in which it lays eggs. This bee is native to Asia, but was inadvertently transported to the United States in the 1990's, where it was first identified in North Carolina in 1994. It is now present in most of the southeastern United States. This bee resembles bumble (Bombus spp.) and carpenter (Xylocopa spp.) bees, except that it lacks both the hairy abdomen that is present on bumble bees and the shiny abdomen that is present on carpenter bees.

Giant resin bees are solitary, though often females will nest near each other. Females create their nests in existing tubes or narrow cavities and they are constructed from resin and sap collected from trees. Females provision each cell with a pollen ball and then lay a single egg in each cell. A female will lay up to 10 eggs. If the nest entrance is directly exposed to the outside, the female will seal it with a resin, wood, and sometimes mud cap. Eggs hatch in the winter. Larvae pupate in late spring and adult bees emerge in the summer.

Giant resin bees are found around decks, porches, and other wooden structures. They are known to nest in vacant carpenter (Xylocopa spp.) and blue orchard bee (Osmia lignaria) tunnels.

The giant resin bee is known to pollinate several plants in the United States, including golden rain tree (Koelreuteria paniculata), waxleaf privet (Ligustrum lucidum), sourwood (Oxydendrum arboreum), catalpa (Catalpa spp.), buttonbush (Cephalanthus occidentalis), and vitex (Vitex spp.). In its native range, the giant resin bee is a known pollinator of crape myrtle (Lagerstroemia spp.) and is the primary pollinator of kudzu (Pueraria montana). Kudzu, a fast-growing perennial vine, is native to Asia. It was introduced to the United States in 1876 and is now common throughout most of the southeast. In the United States, kudzu is known as an invasive weed that kills or degrades native plants. As in Asia, the giant resin bee pollinates kudzu in the United States, aiding its spread throughout the country.