Yellowjacket or yellowjacket is the common name in North America for predatory social wasps of the genera Vespula and Dolichovespula. Members of these genera are known simply as "wasps" in other English-speaking countries. Most of these are black and yellow like the eastern yellowjacket (Vespula maculifrons) and the aerial yellowjacket (Dolichovespula arenaria); some are black and white like the bald-faced hornet (Dolichovespula maculata). Some have an abdomen with a red background color instead of black. They can be identified by their distinctive markings, their occurrence only in colonies, and a characteristic, rapid, side-to-side flight pattern prior to landing. All females are capable of stinging. Yellowjackets are important predators of pest insects.

Identification

thumb|left|Face of a southern yellowjacket ([[Vespula squamosa)]]

Yellowjackets may be confused with other wasps, such as hornets and paper wasps such as Polistes dominula. A typical yellowjacket worker is about long, with alternating bands on the abdomen; the queen is larger, about long (the different patterns on their abdomens help separate various species).

right|thumb|Yellowjacket stinger in its sheath in a [[scanning electron microscope]]

Yellowjackets are sometimes mistakenly called "bees" (as in "meat bees"), given that they are similar in size and general coloration to honey bees. In contrast to honey bees, yellowjackets have yellow or white markings, are not covered with tan-brown dense hair on their bodies, and do not have the flattened, hairy pollen-carrying hind legs characteristic of honey bees (although they are capable of pollination).

Yellowjackets have lance-like stingers with small barbs, and typically sting repeatedly, workers and a nest of 10,000–15,000 cells in late summer. The species V. squamosa, in the southern part of its range, may build much larger perennial colonies populated by dozens of queens, tens of thousands of workers, and hundreds of thousands of cells. At peak size, reproductive cells are built with new males and queens produced. Adult reproductives remain in the nest fed by the workers. New queens build up fat reserves to overwinter. Adult reproductives leave the parent colony to mate. Males die quickly after mating, while fertilized queens seek protected places to overwinter. Parent colony workers dwindle, usually leaving the nest to die, as does the founding queen. Abandoned nests rapidly decompose and disintegrate during the winter. They can persist as long as they are kept dry, but are rarely used again. In the spring, the cycle is repeated; weather in the spring is the most important factor in colony establishment.

The adult yellowjacket diet consists primarily of sugars and carbohydrates, such as fruits, flower nectar, and tree sap. Larvae feed on proteins derived from insects, meats, and fish. Workers collect, chew, and condition such foods before feeding them to the larvae. Many of the insects collected by the workers are considered pest species, making the yellowjacket beneficial to agriculture. Larvae, in return, secrete a sugary substance for workers to eat; this exchange is a form of trophallaxis. As insect sources of food diminish in late summer, larvae produce less for workers to eat. Foraging workers pursue sources of sugar outside the nest including ripe fruits and human garbage.

In the United States

thumb|thumbtime=44|[[Vespula|Yellowjacket wasp at fermenting fruit harassed to leave by aggressive ant]]

The German yellowjacket (V. germanica) first appeared in Ohio in 1975, and has now become the dominant species over the eastern yellowjacket. It is bold and aggressive and can sting repeatedly and painfully. It will mark aggressors and pursue them. It is often confused with Polistes dominula, another invasive species in the United States, due to their very similar pattern. The German yellowjacket builds its nests in cavities—not necessarily underground—with the peak worker population in temperate areas between 1000 and 3000 individuals between May and August. Each colony produces several thousand new reproductives after this point through November.

The eastern yellowjacket builds its nests underground, also with the peak worker population between 1000 and 3000 individuals, similar to the German yellowjacket. Nests are built entirely of wood fiber and are completely enclosed except for a small entrance at the bottom. The color of the paper is highly dependent on the source of the wood fibers used. The nests contain multiple, horizontal tiers of combs within. Larvae hang within the combs.

In the southeastern United States, where southern yellowjacket (Vespula squamosa) nests may persist through the winter, colony sizes of this species may reach 100,000 adult wasps.

The yellowjacket's most visible place in US sporting culture is as a mascot, most famously with the Georgia Tech Yellow Jackets, represented by the mascot Buzz. Other college and university examples include Allen University, the American International College, Baldwin-Wallace University, Black Hills State University, Cedarville University, Defiance College, Graceland University, Howard Payne University, LeTourneau University, Montana State University Billings, Northern Vermont University-Lyndon, Randolph-Macon College, University of Rochester, University of Wisconsin–Superior, West Virginia State University, and Waynesburg University.

Though not specified by the team, the mascot of the Columbus Blue Jackets, named "Stinger," closely resembles a yellowjacket. In the years since its original yellow incarnation, the mascot's color has been changed to light green, seemingly combining the real insect's yellow and the team's blue.

In the United Kingdom the rugby union team Wasps RFC traditionally used a yellowjacket as their club emblem.

The Marvel Comics character Yellowjacket, who is based on the insect, is one of the various identities adopted by Hank Pym, who is most commonly known as Ant-Man. In addition to being able to fly, emit bio-electrictry inspired by a yellowjacket's sting, and shrink down to insect size, Yellowjacket can also control the insect and uses them to aid him in various ways.

The television series, Yellowjackets, features a girls’ soccer team which gets stranded in the wilderness and resorts to extreme measures to survive. Their mascot is a Yellowjacket, and the theme song features images of the insect as well.

Note that yellowjacket is often spelled as two words (yellow jacket) in popular culture and even in some dictionaries. The proper entomological spelling, according to the Entomological Society of America, is as a single word (yellowjacket).

References

  • "Yellowjackets and Hornets of Florida" on the UF / IFAS Featured Creatures Web site
  • Successful Removal of German Yellow Jackets by Toxic Baiting