What do sweat bees do

Sweat bees pollinate wildflowers and various crops, including stone fruits, alfalfa and sunflowers. According to the United States Agricultural Department, sweat bees have more complex digestive and detoxification systems than other bees in order to handle and process the different types of pollen they collect. These bees are found throughout the world, and there are more than 1, species in the United States, Canada and Central America, including 44 species in Florida alone. These bees thrive in temperate regions but are widespread throughout the United States.

Like other bee species, sweat bees may be solitary or eusocial, meaning they live in colonies with each bee performing a specific role. It depends on the species. Sweat bees live underground and burrow holes below the soil. Solitary bees live in individual cells located far apart from one another. Eusocial bees, on the other hand, live in cells that are much closer together. In eusocial colonies, the mated female, known as a gyne, is the queen. She digs burrows underground and carves out cells, then fills each cell with pollen and places an egg inside.

In general, many bee species overwinter as prepupae. Some halictids do the same, including females of the subfamily Rophitinae. In Nomioidinae, both sexes overwinter. In the spring or summer, the females emerge, mate if they have not already done so, and begin digging nests and provisioning cells with pollen and nectar. In each cell they lay a single egg. When the larva emerges from the egg, it consumes the pollen provision until the food is gone.

The larva then defecates, and may or may not remain in this prepupal form that year depending on the species, season or other unknown factors. It is believed that some prepupae remain so for a year or more as a fallback for years of drought. Some prepupae, on the other hand, will pupate immediately and emerge as adults.

Some of these adults also may remain in their cell over the winter, again depending on the species. Figure 7. Augochlora pura adult standing next to a broken larval cell. The yellow pollen balls lining the cell are created by the female before she deposits the eggs.

These provisions then sustain the developing larva until pupation and emergence as an adult. Photograph by Beatriz Moisset. Most species are polylectic, or gather floral resources from multiple plant species.

There are a few oligolectic species and subgenera that feed from a single plant family. Adult halictids eat nectar, and collect nectar and pollen for the larvae.

All halictids are mass provisioners, that is, the adults provision each cell with all the food pollen and nectar a larva will need until it emerges. Figure 8. Lasioglossum sp. Photograph taken in Pierce County, Washington. Photograph by Lynette Schimming. Most halictids nest underground. Species that are parasites of other bees do not build nests at all. Despite usually nesting in the ground, nesting behavior is otherwise highly variable between the species.

Each subfamily has its own characteristic nesting habit:. Figure 9. Adult Halictus scabiosae Rossi, a sweat bee, entering her nest. Photograph taken in Genova, Italy. Photograph by Ettore Balocchi. Figure Typical nest entrance for Augochlorini, a tribe group of genera in a subfamily of sweat bees.

The family Halictidae contains a few social parasites and cleptoparasitic bee genera. While foraging, these insects obtain pollen and nectar from a variety of common flowers. However, sweat bees must supplement their diets with salt and moisture.

This is often accomplished through feeding on human sweat, so the pests can become nuisances during hot days. Unlike honey bees, sweat bees don't produce honey and avoid making nests in attics or wall voids. Still, they sometimes live among buildings, sheds, and patios that contain exposed or damaged wood. Sweat bees are generally docile, but females can deliver a mild sting if swatted or aggravated. At times, they are known to swarm in the hundreds. The pests love burrowing through bare soil in sunny locations.

Property owners with treeless, well-lit yards often experience infestations. In cases of large numbers of sweat bees, homeowners should contact Orkin for assistance.