Yellowjackets

Yellowjackets (or yellow-jackets) are social wasps that live in colonies and build enclosed paper nests like that of the hornet. There are two types of yellowjackets, “Aerial Yellowjackets” which construct exposed paper nests above ground and “Ground-Nesting Yellowjackets” who make their nests below ground. Both are often mistaken for bees, sometimes they´re called “meat bees” but unlike bees, yellowjackets are relatively hairless and they are carnivorous. The Western Yellowjacket (Vespula pensylvanica) is usually of the ground-nesting variety but there have been reports of nests in attics and in wall voids of homes. This yellowjacket is easily identifiable by the complete yellow ring around the eye, although in males, the ring is interrupted and sometimes it is absent. If you´ve ever been stung by a yellowjacket, you know just how painful it can be and probably didn´t care whether the ring around the eye was complete or not!

Yellowjacket Eating Habits

Of all the social wasps, yellowjackets are considered to be the greatest nuisance, especially at picnics and barbeques. The yellow and black invader is often an uninvited guest at family picnics and outdoor gatherings, anywhere there is food. They absolutely love sweets but will just as well attack a baloney sandwich. If food is left out, yellowjackets will be sure to partake of it; from open soda cans, cakes and cookies, and let´s not forget their need of protein – fried chicken often will do as well as a variety of lunchmeats. In nature, yellowjackets feed on over ripe fruits and dead insects but since they are scavengers and opportunists, yellowjackets eat just about anything, including dog and cat food. If yellowjackets are seen in the garden, it´s usually because they are foraging for honeydew from infested plants. Adult yellowjackets also take back small bits of caterpillars, flies, etc. to the nest to feed to their larvae; in exchange, the larva secretes a sugary substance which is then consumed by the worker yellowjackets.

Video of Yellowjacket Nest and Larvae

This is a video of aerial yellowjackets that have made their nest near a doorway inside of a wall.

Life Cycle of Yellowjackets

Like other social wasps, yellowjackets have an annual life cycle. Summer is the height of yellowjacket season, by the end of summer when the nests are full of multiple combs and thousands of cells, the colonies begins to produce males for the strict purpose of mating as well as produce new queens. Come fall, these new queen and male yellowjackets mate; afterwards, the male dies and the rest of the colony soon follows suit. Only newly mated queens survive the winter by over-wintering in sheltered areas such as abandoned rodent nests, under tree bark or rocks, and in window shutters or roof shingles. Once spring arrives, the queen yellowjacket emerges to establish a new colony and begins to construct the initial part of the paper. After laying 10 – 20 eggs, she cares for her first brood of workers until they are old enough to not only take care of her but to build upon the nest, continuing the annual cycle of life well into the summer months.

Pest Control for Yellowjackets

Most yellowjackets construct their nests underground which makes them difficult to locate. If the nest is large, the surface of the soil may bubble, making it easier to find. Only a professional should rid your landscape of any underground yellowjacket nests. Care should be taken if you see yellowjackets nearby when gardening and/or mowing the lawn. Since yellowjackets are scavengers, trashcans should have lids on them, pet food shouldn´t be left out, at least not during the summer months when yellowjacket numbers are at their peak. Keeping food covered as best as possible, including soda cans, at picnics and barbeques will prevent friends and loved ones from unnecessary stings. References Mallis, A. Handbook of Pest Control, Tenth Edition, Saunders College Publishing, 2011. Print Imes, R. The Practical Entomologist, A Fireside Book, Simon & Schuster Inc., 1992. Print University of California Agricultural & Natural Resources, UC Riverside, IPM (Integrated Pest Management). Online Wikipedia. “Western Yellowjacket.” Retrieved from en.wikipedia.org/wiki/Vespula_pensylvanica. Online Please contact us if you suspect a yellowjacket nest near your home: