Bumblebees, farm-and-garden helpers

Spring has sprung, plants are budding and flowers are blooming. While walking past my friend’s daffodil garden, I noticed some bumblebees flying from flower to flower in their quest for nectar. While they forage for nectar and pollen, they also pollinate the plants they visit. This is essential for the production of wild plant seed or cultivated fruits and vegetables.

The bumblebee (Bombus bimaculatus) is a hairy black bee with yellow banding, and is slightly larger than a honeybee. Like the honeybee, the bumblebee is considered a social insect, though the number of bumblebees in a colony is relatively small compared to the honeybee.

Bumblebees usually nest in a cavity in the ground, frequently in old rodent burrows. The nest consists of a queen, undeveloped female workers and males. The queen will start the nest in the spring with the first brood, numbering from five to 20, all being worker females. Later broods produce reproductive males and females, and in late summer these will fly and mate on the wing. In the fall, the fertilized females will find a sheltered place to hibernate, and establish new nests as queens in the spring. The workers and males will die during the first hard frost.

Bumblebees resemble the wood-boring carpenter bee. Close examination reveals that the bumblebee has dense yellow hairs on the abdomen, and the carpenter bee does not.

Farmers and gardeners should use insecticides with care to avoid harming this important ally.