Yellowjackets

Yellowjackets (Vespula spp., Dolichovespula spp.) are so named for their distinctive yellow and black markings. They are relatively hairless, with wings that are often a translucent golden-tan color. Yellowjackets are house fly-sized, ranging from 12-25 mm. They are common worldwide, and are particularly abundant in the southeastern United States. Yellowjackets are carnivorous, primarily feeding on other insects like flies and bees, but also on fruits, picnic fare, carrion, and the nectar of some flowers.

Yellowjackets are social wasps - this means that they live colonially in hives or in wasp communities. In contrast, solitary wasps build and live in individual nests rather than in a hive or with a colony of wasps. A queen emerges in the spring and begins constructing her nest of paper, often times underground. She lays a single egg in each cell; larvae hatch a few days later. After she has produced enough workers to take over nest-building and foraging, the queen remains inside to reproduce. A full-size nest exists in the fall, with between 600 and 800 workers. In the late summer, males and future queens are produced; they leave the nest to mate. After mating the male dies and future queens overwinter alone in protected places like under tree bark, in old stumps, and sometimes attics. Nests are not reused the following year.

Nest locations include lawns, the base of trees or shrubs, and sometimes attics or wall voids of houses or storage buildings.

Yellowjackets occur worldwide. They are widely distributed in the northern hemisphere, and are especially common in the southeastern United States.

Although not known for their pollination services - they lack pollen carrying structures such as pollen baskets and are relatively hairless - yellowjackets do indeed act as pollinators. An interesting relationship exists between yellowjackets and the broad-leaved helleborine (Epipactis helleborine), an orchid native to Europe but introduced in the eastern United States. The yellowjacket lands on the labellum (the showy, lowest petal) and drinks nectar. While doing so, it bumps its head on the anther and pollen becomes glued to the yellowjacket's head. To prevent the yellowjacket from grooming itself and potentially causing the pollen to become dislodged, some of this plant's nectar is converted to ethanol. This causes the yellowjacket to become intoxicated and to behave sluggishly. While in this state, the yellowjacket is less likely to groom itself and thus leaves the pollen on its head. During its next floral visit, the yellowjacket inadvertently deposits pollen onto the flower, thereby pollinating it. Yellowjackets have also been known to nectar from, and likely pollinate, common rhododendron (Rhododendron ponticum), squash (Cucurbita spp.), common milkweed (Asclepias syriaca), field garlic (Allium oleraceum), and field pussytoes (Antennaria neglecta).