Yellow Jackets
Vespula sp., Vespidae, HYMENOPTERA

DESCRIPTION

Adult -- The adults are distinctly marked with black and yellow. The wings are usually a translucent golden-tan. They range in size from 12 to 25 mm.

Egg -- The eggs are milky white and typically "sausage-shaped." They are about 1 to 2 mm in length.

Larva -- The legless larva is creamy white and ranges from slightly larger than the egg at hatching to near adult size at maturity. The first three instars are fixed to the cell wall. The last two instars are able to move about within the cell.

Pupa -- The pupa resembles a mummified adult. It is the same length as the adult.

BIOLOGY

Distribution -- Yellow jackets are widely distributed worldwide. They are very common in the southeastern U.S. Nests are usually constructed underground. Yellow jackets are active from spring until late fall. They are found foraging throughout the day, but are most active during mid-day.

Feeding Habits -- Adults feed on a wide variety of food sources. Carbohydrates are obtained from nectar, honeydew secreted by aphids, scale insects and other insects, and from various fruits. Larvae and adults of various insects provide most of the protein requirements of yellow jackets. Many larvae of insect pests are killed by wasps feeding on them.

Damage -- Workers and queens can inflict painful stings if provoked. Males are harmless. No real damage is done to turf. Since all soil excavated from the nest site is carried away, no mound is associated with the entrance.

Life History -- Yellow jackets overwinter as mature, fertilized queens. In the spring a queen seeks out a suitable nest site and builds a single comb composed of several cells. A single egg is laid in each cell. After a few days the larvae hatch from the eggs. The queen forages for food and feeds these first larvae. She also enlarges the comb with additional wood pulp. After the first workers hatch, all nest construction and brood care is done by the workers and the queen restricts her activity to egg laying. Over the summer the nest is enlarged until there are several layers of comb enclosed in a paper envelope. In late summer, males and future queens are produced. They leave the nest and mate. After mating the males die and the females seek out suitable sites in which to overwinter.

CONTROL

Unless yellow jackets are a nuisance, controls are usually not required. Individual nest sites should be treated at night when all workers are in the nest. One of the aerosol products labeled for wasp control should be used. Consult the local agricultural extension service for additional control recommendations.