SHARP-EATMAN
NATURE
PHOTOGRAPHY
ID GUIDE TO WILD BEES
OF THE NATIONAL BUTTERFLY CENTER
Mission, Texas
BUMBLE BEES
Bombus
BUMBLE BEES
Genus Bombus
Bumble bees are the best known of wild bees: they are easily recognized by their robust, furry-looking yellow-and-black bodies and by the loud buzzing sound they make when they zoom by. Bumble bees' genus name, Bombus, is Latin for "buzzing" or "rumbling".
Many wild bees are solitary creatures. Bumble bees, however, build colonies with a complex social structure similar to that employed by honey bees. Bumble bee colonies each contain a queen, male drones and female workers. Queens lay eggs; male drones fertilize the queens; and workers perform various tasks necessary to sustain the colony, such as incubating eggs, feeding larvae and guarding the hive.
Bumble bee colonies are more modest in size than those of honey bees. While honey bee hives may contain tens of thousands of bees, bumble bee nests usually harbor a few hundred at most. While honey bees form nests employing a complex architecture of close-fitting hexagonal cells, bumblebee nests often resemble a hodgepodge of "honey pots," or wax cup-shaped structures used to store nectar.
Bumble bees often nest in the ground, where their colonies are less likely to be disturbed than honey bee nests. Bumble bees also tend to be less aggressive than honey bees.
Female bumble bees carry pollen in rounded masses tucked into pollen baskets, called corbiculae, located on the bees' hind legs and made up of fine, interwoven hairs. Bumble bees' hefty size allows them to carry relatively large pollen loads, making them highly efficient pollinators.
Economic importance: The prowess of bumble bees as crop pollinators is surpassed only by honey bees. Bumble bees are essential in the pollination of blueberries and tomato-family crops, (such as tomatoes, peppers and eggplants), which require vibratile or "buzz" pollination, in order to bear fruit. Bumble bees engage in buzz pollination by vibrating their flight muscles to shake pollen from the anthers of flowers. Many bees, including honey bees, are unable to buzz pollinate.
Texas bumble bees / threatened species: At least nine bumble bee species occur in Texas: Bombus auricomus, B. bimaculatus, B. fervidus, B. fraternus, B. griseocollis, B. impatiens , B. pensylvanicus, B. sonorus and B. variabilis.
Many bumble bee species are currently in decline throughout the United States. The Texas Parks and Wildlife Department has classified three Texas bumble bees in the category of "greatest conservation need" under the Texas Conservation Action Plan: the American bumble bee (Bombus pensylvanicus); its close relative, the Sonoran bumble bee (Bombus sonorus); and the variable cuckoo bumble bee (Bombus variabilis). The IUCN (nternational Union for Conservation of Nature) additionally has placed the Yellow Bumble Bee (Bombus fervidus) on its red list of vulnerable species.
At this time (2026), a single bumble bee species thrives in the Lower Rio Grande Valley: the American bumble bee (Bombus pensylvanicus). Sightings of other species are rare; Bombus sonorus, once documented in Hidalgo County in the 1980's, has not been recorded there since.
The black & yellow bands on the abdomen of a female American bumble bee
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An 1840 engraving by Lizars, William Home Lizars of a bumble bee nest.
A female bumble bee carrying orange pollen in its corbiculae (pollen baskets)
TAXONOMY OF BUMBLE BEES
Order: Hymenoptera
Family: Apidae
Subfamily: Apinae
Tribe: Bombini
Genus: Bombus
Species shown below:
Bombus pensylvanicus (American bumblebee)
Bombus sonorus (Sonoran bumblebee)
Bumble Bee Species of the Lower Rio Grande Valley
American bumblebee
Bombus pensylvanicus
Family: Apidae
Family: Apidae
Size of worker: 14-18 mm
Size of male: 16-22 mm
Size of queen: up to 25 mm
Associated flora:
Silver-leaf nightshade
(Solanum elaeagnifolium)
Plant Family: Solanaceae
Common Sunflower
(Helianthus annuus)
Blanketflower
(Gaillardia)
Plant Family: Asteraceae
Esperanza
(Tecoma sans)
Plant Family: Bignoniaceae
When seen:
September 2018,
October 2019 & May 2021
National Butterfly Center
(Hidalgo Co.)
South Padre Island B&N Center
(Cameron Co.)
A female worker American bumble bee (Bombus pensylvanicus) on a blanketflower.
Rear view of the female bee's abdomen: the front segments (T1-T3) are yellow, and the rear segments (T4-T6) are black. On queens, the frontmost segment may be partly or entirely black.
Dorsal view of the female's thorax: the hairs on the front third are pale yellow. The hairs on the back portion are predominantly black.
View of the black rear portion of the female worker bee's thorax. On some individual females, mixed black-and-pale hairs may fringe the rear thorax.
A male American bumblebee: on male American bumble bees, the first four abdominal segments (T1-T4) are covered with yellow hairs; T5-T7 may be yellow, yellow intermingled with black, or black. T7 sometimes sports orange hairs on the tip.
Rear view of male bee's abdomen
The male American bumblebee's thorax is pale yellow in front, and black behind. The rear third may have some yellow hairs commingled with dark hairs, as shown on the bee here.
The hind leg of a male American bumblebee: unlike their female counterparts, males lack pollen baskets on their hind legs.
A female American bumble bee (Bombus pensylvanicus) on blanketflower
A male American bumble bee
The American bumble bee (Bombus pensylvanicus) is the dominant bumble bees species of the Lower Rio Grande Valley. This is a large, beautiful bee with a black head covered with predominantly black hairs; a thorax usually clothed with yellow hairs on the front third and black hairs behind; and an abdomen with black- and yellow-haired bands. The bees' legs are black, and their wings are dark with dark veins.
On female workers, the front three abdominal segments (T1-T3) are usually yellow. (On queens, T1 may be yellow, black, or partly black.) The remaining segments (T4-T6) on females' abdomens are banded with mostly black hairs. On males, the front four segments (T1-T4) are usually yellow. The rear segments (T5-T7) may be yellow or or have black hairs intermingled with yellow. Abdominal hair patterns may vary among individual bees: on some males, for example, the rearmost segment may have some orange hairs.
Associatied flora: The American bumble bee is an eclectic generalist pollinator that visits flowers from more than twenty plant families. It is among a small group of bees in the Lower Rio Grande Valley that pollinate silverleaf nightshade (Solanum elaeagnifolium), a common LRGV wildflower of the tomato family, with silvery blue-green leaves and showy purple-and-yellow blossoms.
In the Lower Rio Grande Valley, American bumble bees also commonly visit purple passionflower (Passiflora incarnata), esperanza (Tecoma stans), Texas prickly pear (Opuntia engelmannii) and large composites such as sunflower (Helianthus), blanketflower (Gaillardia pulchella) and cowpen daisy (Verbesina encelioides).
American bumble bees prefer open farmland and grassland, and commonly make their nests in shallow depressions under mats of grass. Their tendency to nest above ground, where they are susceptible to predators, makes them more aggressive than most bumble bees.
Sonoran bumblebee
Bombus sonorus
Family: Apidae
Size of worker: 14-18 mm
Size of male: 16-22 mm
Size of queen: up to 25 mm
When last seen:
August 27, 1983
Bentsen-Rio Grande State Park
October 1, 1988
Weslaco, (near Llano Grande SP)
A female Sonoran bumble bee Photo Copyright 2026 Kathryn Wells
A bright yellow Sonoran bumble bee Photo Copyright 2018 Greg Lasley
Recommended references:
Beckham, Jessica L, Jeff A. Johnson, & Russel S. Pfau. 2024. "Molecular data support Bombus sonorus and Bombus pensylvanicus (Hymenoptera, Apidae) as distinct species." Journal of Hymenoptera Research. 97: 895–914.
Koch Jonathan, James Strange, & Paul Williams P. 2012. Bumble bees of the western United States. Washington (DC): USDA Forest Service, Pollinator Partnership.
Villalobos, Ethel M., & Todd E. Shelly. 1987. "Observations on the behavior of Male Bombus sonorus (Hymenoptera: Apidae)." Journal of the Kansas Entomological Society, vol. 60, no. 4 541-548.
ID Information: In the field, Sonoran and American bumble bees can be differentiated by hair patterns on the thorax: on Sonoran bumble bees, a clearly-defined broad band of black hairs bisects a yellow-haired thorax. By contrast, the typical American bumble bee’s thorax is divided into a yellow-haired front portion and black-haired back portion.
Young Sonoran bumblebees are sometimes described as being a bright "saffron" yellow (rather than a more typical pale or golden yellow). The electric-yellow coloring of the bee shown here on a purple thistle is an example. Sonoran bumble bees tend to become a paler yellow as they mature.
Otherwise, Sonoran and American bumble bees are quite similar. They are large bees with black heads and legs and dark wings. The patterns of black and yellow hairs on their abdomens mirror those of American bumblebees, as described in the above guide entry.
Range: This species currently ranges from southern and central California through the southwestern United States and into Texas. It has been found as far east as Oklahoma, and it ranges through Mexico to its southern border. Within Texas, Bombus sonorous is most likely to appear in the western part of the state, although it ranges into central Texas and is still documented occasionally near South Texas. Notably, Bombus sonorus is found in Tamaulipas and Nuevo Leon, the two Mexican states that border the Lower Rio Grande Valley.
Floral associations: Bombus sonorous is a generalist pollinator that feeds on plants of diverse families. Like Bombus pensylvanicus, the Sonoran bumble bee visits, among others, aster-family flowers such as sunflower (Helianthus), black-eyed Susan (Rudbeckia) and cowpen daisy (Verbesina encelioides); cacti such as prickly pear (Opuntia); and tomato-family plants including slenderleaf nightshade (Solanum elaeagnifolium).
We include the Sonoron bumble bee (Bombus sonorus) in this Guide to Bees of the Lower Rio Grande Valley, with the note that this species has not been formally documented in the Valley in nearly forty years. It was last recorded in Hidalgo County, at Bentsen-Rio Grande State Park (in 1983), and in Weslaco, near Estero Llano State Park (in 1988). The Sonoron bumble bees shown here were photographed in Denton and Travis Counties (of North and Central Texas) by nature photographers Kathryn Wells and Greg Lasley.
If you find this species in the Lower Rio Grande Valley, please document and report your finding via iNaturalist, Bug Guide or another species-tracking database.
Species history. The entomological history of Bombus sonorus has been rocky: it alternately has been deemed a subspecies of the American bumblebee (Bombus pensylvanicus) and a separate species in its own right. American and Sonoran bumble bees are similar in appearance, visit similar flora and often occupy the same areas concurrently. However, they have been found not to hybridize in shared habitats, and recent studies examining molecular data have determined that Bombus sonorus is a distinct species (Beckham, J. et al. 2024).
CITE THIS PAGE: Sharp, Paula and Ross Eatman. "Bombus." Wild Bees of the National Butterfly Center of Mission, Texas. 15 Jan. 2019, http://www.wildbeestexas.com. Accessed [day/month/year guide accessed].