Bumble Bees

Common Name: Bumble Bees

Introduction: The common name of bumblebee possibly comes from their rather large clumsy appearance and loud buzzing sound they make as they fly. In the urban setting, bumble bees occasionally nest in structures, beneath landscape features and are of concern because of their abundance around the many flowering plants typical of yards, and because they can sting. There are about 45 species in the United States and Canada, and about a dozen species in Ohio.

Recognition: The adult worker body length is 1/2 to 1 inch, while queens’ measure 3/4 to 1inch or more long. Bumblebees are robust in form with an overall fuzzy appearance, including the top surface of abdomen. They are broadly banded with black and yellow patterns. The stinger is usually not left behind when used. [The honeybee leaves behind its stinger when used.]

Habits: Overwintered queen bumblebees will select an appropriate nesting site the following spring. Some queens locate a small, dark cavity containing fine plant fiber, in which to nest. The abandoned underground nests and burrows of mice, voles and chipmunks are favorable sites. Other queens select a dense clump of grass on the surface or sheltered pile of grass clippings for a nest.

Bumblebees foraging for nectar fly at 7-12 mph and spend only 2-4 minutes inside the nest between trips. Probably they will travel at least 3 miles if necessary for nectar. They orientate by the sky polarized light via their 3 ocelli (simple eye spots clustered on top of the head), so they can forage at early dawn and at dusk when objects and landmarks are not well lighted. They use their theromoregulation procedure to warm up flight muscles before the sun rises and to also forage when temperatures are below 50º F. Each worker forages independently, and bumblebees never exchange food. Old cocoons are used to store both pollen and nectar. Only enough food (honey and pollen) for a few days is stored at any given time which helps discourage nest predation by skunks, foxes, etc. Using their relatively smooth stingers that can be used repeatedly usually does defense. Some species will also spray feces, and some cover the intruder with regurgitated honey. People sensitive to insect venom should exercise care around bumblebee nests. The sting of bumblebees is sharply painful and usually results in considerable swelling.

Mechanical protection measures: During the day finds the location of each nest by observing where the bees disappear into the ground, grass clump, or structure. The location of the entry hole can be marked with a small, brightly colored object placed near it to facilitate discovery by the pest management professional who comes to treat the colony. Under no circumstances should the entrance hole to a structural nest be closed off until the colony has been destroyed.

Wingate Professional Procedures: Bumble Bees are considered beneficial insects because they pollinate the flowers of many plant species. However, if their nest is located in or close to an occupied structure or recreational area, then control is warranted. A Wingate technician will liberally inject a residual insecticide dust into the nest entrance. For structural nests, the cavity will be treated with a dust or aerosol formulation but the entrance will not be sealed until the colony has been destroyed. Treated structural nests will be removed, if accessible, to prevent future problems with secondary pests, such as dermestid beetles, wax moths and psocids.