Vespula maculifrons
eastern yellowjacket

Found throughout Eastern North America

The Eastern Yellow jacket is a subterranean species, meaning it builds its nest below the ground. It is a generalist species, and so can live happily in urban, suburban, and agricultural areas. (Duncan, 1939; Evans, 1963; Ross and Matthews, 1991)

The Eastern Yellow jacket ranges in size from 1.25-1.8 cm long, depending on its caste (queen, worker, male). Perhaps the most distinguishing features on the Eastern Yellow jacket are the black and yellow stripes that accent the abdomen. The patterns on the abdomen are also determined by caste. Vespula malculifrons workers are typically 1.25 cm in length and have abdominal markings that consist of thick black bands with a sliver of yellow between each band. The male yellow jacket is the same size, but he has a slightly different pattern of black and yellow than the worker. Males have one thick black band at the region closest to the thorax and as the band progresses towards the anus, the black bands decrease in thickness while the yellow bands increase in thickness. The queen Eastern Yellow jacket is slightly larger than the male and worker at 1.8 cm. The queen's markings consist of a large flared black band at the anterior region of the abdomen followed by thinner bands of black that progresses to the posterior end of the abdomen. In between the black bands are two dots that, if the point of the flare were extended towards the anus, would be located on either side of the imaginary line.

Female Eastern Yellow jackets have a stinger located on the posterior end of the abdomen (gaster). The yellow jacket is able to sting its victims repeatedly, however the stinger is slightly barbed and has a tendency to become stuck in the victim.

The yellow jacket also has well-developed mouthparts that are specially designed to capture and chew prey (such as many kinds of caterpillars). Along with strong jaws the yellow jacket has a highly developed tongue for sucking nectar and fruit juices from the plants.

(Lyon, 2000) (Grissell, May 1999; Ross and Matthews, 1991)

Yellow jackets hatch from the egg as small, white, grub-like larvae. As they grow they feed on paste made from masticated insects that workers feed them. Once they have grown large enough they pupate. During this time they undergo a complete metamorphosis and emerge in their mature adult form.

The larval stage for the queen lasts about 12-18 days, while the larval stage of workers and males is slightly less. (Duncan, 1939; Ross and Matthews, 1991)

Worker individuals live untill the first serious frosts of winter. Males die shortly after mating, while queens live for one year; building a nest and founding a colony the summer after which they mated.

The Eastern Yellow jacket is generally a peaceful creature but will not hesitate to attack when it feels threatened. The stinger of Vespula maculifrons is used only for defense and plays no role in capturing prey. Instead, yellow jackets use their powerful jaws (mandibles) to capture and kill prey, and may sometimes use these mandibles to bite as well as sting while defending themselves.

A normal colony of Eastern Yellow jackets holds 2,800- 5,000 individuals during the peak of the season. One interesting habit the Eastern Yellow jacket has is that once the queen begins to lay the male and female eggs, the workers start eating all the undeveloped larvae that have not yet hatched. Scientists do not understand why this is, but believe it is so all the attention and energy of the colony is focused on next season's queens.

The V. maculifrons queen is the initial constructer of the nest. First she makes a small disc from paper, followed by a hollow stalk called a pedicel, and finally she builds small larval cells onto the flat cells on the end of the pedicel. Then she builds an envelope around all of the cells, leaving only a small opening at the base. Once the initial nest is completed, the queen will lay some eggs, one in each cell, that develope into the first generation of workers.

The nest is constructed from rotten or weathered wood fibers, dead plant stem fibers, the linings of shrubs and trees, cocoon silk and various artificial fibrous materials such as paper bags and newpapers. These fibers are then mixed with saliva and chewed to a pulp. Once the pulp has been made the workers begin to build larger and larger cells. Typically, the combs are built for the second tier before the first tier has been completed.

The nest is usually kept between 29 and 32 degrees Celsius.

(Lyon 2000) (Duncan, 1939; Evans, 1963; Ross and Matthews, 1991)

Sight and smell play a key role in the ability to locate food. First, sight helps the yellow jacket recognize flowers and potential prey. Next, smell helps guide these creatures to the particular flower from which she likes to drink. Chemical signals help wasps identify nest mates from potential competitors and enemies. Chemical signals called pheromones also help wasps communicate with one another about mating, food, and danger.

(Lyon, 2000) (Duncan, 1939; Evans, 1963)

Adult yellow jackets feed only on nectar and fruit juices using their long tongues, while animal tissues (mostly insects and other arthropods, but occasionally carrion) are fed to larvae. Larvae jiggle around in their cells alerting nearby workers that they are hungry. A worker will then proceed to go out and capture a prey item. She then cuts the prey item into manageable pieces and carries it back to the nest piece by piece. Once the prey item is in the nest the worker masticates (chews) a piece of the prey into a paste with her mandibles. The workers then feed the larvae by tickling them. This tickling causes the larvae to secrete a liquid from their salivary glands. The worker feeds on the liquid, and while she is drinking she transfer the chewed up paste to the larvae. This process is termed malaxation. (Andrews, 1969; Duncan, 1939; Ross and Matthews, 1991)

Eastern Yellowjackets will sting vigorously to defend themselves and their nest, so they can be a nuisance if the nest is located around people. Some people are especially allergic to the venom, and can have a very dangerous, or even fatal, reaction to being stung. These sites give suggestions on how to deal with yellowjacket nests:

(Lyon 2000) (Grissell, May 1999)

Despite what many people think, the Eastern Yellowjacket provides a valuble service to farmers and gardeners by destroying many insects that attack cultivated and ornamental plants. (Grissell, May 1999)

The Eastern Yellowjacket is found abundantly and is in no danger of becoming endangered. However, there is a non-native species, the German Yellowjacket, Vespula germanica that has recently moved into North America. This species is more aggressive than native yellowjackets, and may out-compete them. It is also more of a nuisance, as it nests more frequently in man-made structures.

(Lyon 2000)