Sonoran Bumble Bee

Tex. west to Calif. (Ariz., Calif., Nev., N. Mex., and Tex.); Mexico (Aguascalientes, Baja California, Chihuahua, Coahuila, Distrito Federal, Guanajuato, Hidalgo, Jalisco, Mexico, Michoacan, Morelos, Nuevo Leon, Oaxaca, Puebla, Queretaro, San Luis Potosi, Sonora, Tamaulipas, Veracruz, Yucatan, and Zacatecas).

In the spring, a queen emerges from hibernation and builds a nest. Offspring take over the chores of nest construction and food collection and the queen continues to reproduce. Towards the end of summer, the queen produces drones. The drones and workers die and newly mated queens fly to a new nest site to overwinter. This bee travels in small colonies of a few dozen to several hundred bees.

This bee thrives in arid regions with temperate climates. Nesting sites are often found in or near the ground in previously occupied burrows. They will occupy structures created by humans such as decks, patios, attics, stairways, and sheds as well as woodpiles and leaf piles.

The Sonoran bumble bee (Bombus sonorous) is named because it is the only bumble bee regularly found in the Sonoran Desert; its native range is from the Californian Central Valley south and east to western Texas and Mexico. Sonoran bumble bees are large, growing between two and four cm. They are yellow and black and are very hairy. This species is believed to be in decline.

The Sonoran bumble bee (Bombus sonorus) forages on a wide variety of desert plants and is a pollinator of many including stick-leaf blazing star (Mentzelia pumida), yellow trumpet bush (Tecoma stans), and Schott's century plant (Agave schottii). It is also considered a better pollinator of desert willow (Chilopsis linearis) than the European honey bee (Apis mellifera), and will forage on the plant even after it has been nectar-robbed by California carpenter bees (Xylocopa californica). The Sonoran bumble bee was listed as a species in decline by the Status of Pollinators in North America (2007) report published by the National Research Council. Possible reasons for this decline include habitat alteration, pesticide use, and pathogen spillover from commercial bumble bee colonies.

Bombus sonorus, commonly known as the Sonoran bumble bee, is a species of bumble bee in the family Apidae. It is found in Central America and western and southwestern North America. Considered uncommon, it is sometimes categorized as a subspecies of Bombus pensylvanicus.