Flower faithful native bee makes a reliable pollinator

A female sweat bee, marked with a nontoxic dot of blue paint, resting on the petals of a crepe myrtle. Photo Credit: Jacob Cecala/UC Riverside

Entomologists at UC Riverside have documented that a species of native sweat bee widespread throughout North and South America has a daily routine that makes it a promising pollinator. 

Because the bee can thrive in environments that have been highly modified by humans, such as cities and agricultural areas, it could become a suitable supplement to honeybees, which are expensive for farmers to rent and threatened by pesticides and climate change.

Sweat bees are not as famous as their prolific cousin, the European honeybee, but are common in natural, urban, and agricultural areas in North America. Sweat bees, along with other native bees like bumble bees, are valuable pollinators of many wildflowers and cultivated crop plants, yet often do not receive the level of public attention that honeybees do. 

In a paper published in the journal Ecology, Ph.D. candidate Jacob Cecala, and Erin Wilson Rankin, an associate professor of entomology, describe in-depth for the first time a foraging behavior of a small, common, and often-overlooked species of sweat bee, Halictus ligatus. The species is classified as a “generalist,” meaning it is known to feed on many kinds of flowers. But no one knew how flexible individuals are in their flower selection, and whether an individual’s floral choices varied day-to-day.