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 "deep roar".
Many wild bees are solitary creatures. Bumble bees, however, have the distinction of being the only native bees in this guide that build colonies with a complex social structure, the kind we associate with honey bees.
Like honey bees, bumble bees form colonies that 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 workers at most. In addition, bumble bees tend to be far 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 efficient pollinators.
The economic importance of bumble bees as crop pollinators is surpassed only by honey bees. This is in part because tomato-family crops, including tomatoes, peppers and eggplants, require "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: EIght bumble bee species occur in Texas: Bombus auricomus, B. bimaculatus, B. fervidus, B. fraternus, B. griseocollis, B. impatiens , B. pensylvanicus, and B. variabilis. Also found in Texas is the Sonoran bumble bee (Bombus sonorus): some entomologists classify this as a variation on the American bumble bee (Bombus pensylvanicus); others hold that the Sonoran is a distinct species in its own right.
Many bumble bee species are currently in decline throughout the United States. The Texas Parks and Wildlife Department has classified three kinds of 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 pensylvanicus sonorus); and the variable cuckoo bumble bee (Bombus variabilis). The International Union of Nature additiionally has placed the Yellow Bumble Bee (Bombus fervidus) on its red list of vulnerable species.
The American bumble bee is well-established at the National Butterfly Center, where it can be observed through mid-autumn. This species is among the few that pollinates silver-leaf nightshade, a wild Texas plant with showy purple-and-yellow flowers that is a member of the tomato family. American bumble bees are also frequent visitors of NBC plants in the sunflower family, such as blanket flowers, common sunflowers, cowpen daisies and goldeneye. Detailed photographs of an American bumble bee are shown below.
A bumble bee carrying bright orange pollen in its pollen baskets
The black and yellow bands on the abdomen of a female American bumble bee
TAXONOMY OF BUMBLE BEES
Species shown below:
Bombus pensylvanicus (American Bumblebee)
Bumble Bee Species of the National Butterfly Center
Size: 14-18 mm (female worker)
Size: 16-22 mm (male)
Food plants at NBC:
Plant Family: Solanaceae
Plant Family: Asteraceae
Tecoma sans)Plant Family: Bignoniaceae
A female American bumble bee (Bombus pensylvanicus) on blanket flower
A female American bumble bee with its head buried in a blanket flower
A male American bumble bee