Western Yellowjacket Pest Profile

Common Name:
Western Yellow Jacket

Scientific Name:
Vespula pennsylvanica

Order and Family:
Vespidae, Vespid Wasps

Pest Control Service Recommendation:
Yellow Jacket Removal

Description:
1/2-5/8″ (12-16 mm). Body stout, slightly wider than head. Abdomen narrow where attached to the thorax with short “waist” (pedicel). 1st antennal segment yellow, 2nd and subsequent segments black. Head, thorax, and abdomen black and yellow or white. Wings smoky.

Food:
Adult eats nectar. Larva feeds on insects pre-chewed by adults.

Life Cycle:
In spring mated female constructs a small nest and daily brings food to larvae until 1st brood matures and females serve as workers, extending nest and tending young. In late summer males develop from unfertilized eggs and mate. When cold weather begins, all die except mated females, which overwinter among litter and in soil.

Habitat:
Meadows and edges of forested land, usually nesting in-ground or at ground level in stumps and fallen logs.

Range:
Throughout North America; various species more localized.

Discussion:
Yellowjackets can be pests at picnics, and they will carry off bits of food. If the nest can be found and its opening covered at night with a transparent bowl set firmly into the ground, adults will be confused by their inability to escape and seek food in daylight; they will not dig a new escape hole and will soon starve to death. The Western Yellow Jacket (V. pennsylvanica) and Eastern Yellow Jacket (V. maculifrons) are similarly colored, except the first antennal segment of the latter is all black.

WARNING: Workers will sting repeatedly if they perceive you as a threat to their nest, otherwise, they are less aggressive.