Often confused with bees, yellow jackets are much more aggressive, and most reported “bee stings” may in fact be yellow jacket stings.
In spring and early summer, yellow jackets are carnivores, feeding mostly on insects to provide protein to developing larvae in their colony. In doing so, they help keep garden pests, such as caterpillars, in check. As the season progresses, their population grows and their diet changes to include more sugars. As natural food sources become scarce, they turn to scavenging, and that’s when you’ll find them lurking around garbage cans and pestering picnickers. A few yellow jackets here and there are a nuisance, but a nest of them in your yard can pose a real hazard.
When Yellow Jackets nest in trees, shrubs, under decks, or high in the eaves, their nest is very visible and easy to identify; a “football” or upside down teardrop-shaped nest constructed from gray paper. Yellow Jackets, like wasps and hornets, actually make this paper themselves by chewing on tiny slivers of wood. The young are hatched and food is stored in the nest’s center or “core” of hexagonal (or six-sided) cells.
When yellow jackets nest inside a structure (such as your home) the nest is not at all visible. You’ll see them flying in and out at some small gap, crack, or crevice on the exterior of your house.
Characteristics: Yellow Jackets are easily distinguishable by their yellow and black coloring. Measuring in length from 12mm to about 16mm, the Yellow Jacket is a common sight throughout all of North America. These flyers are commonly found along the edges of forests and can make their hives nearer the ground than in trees like other wasps might do.
Adult Yellow Jackets will feed off of nectar while other adults pre-chew insects for consumption by the larva. A pregnant female will begin next construction in the spring, bringing about the first generation of Yellow Jacket for the year. Females from this brood will become hive workers and tend to the other young presented later. By the fall – or when cold weather begins to make its appearance – the males of the next will die off leaving only other mated females to continue generations the following year.
Yellow Jackets, particularly the females, are extremely aggressive and will sting repeatedly so avoidance is the best policy! Though avoidance is not always possible, do not swing at the Yellow Jacket as they can be easily provoked to attack.
An Eastern (V. maculifrons) and Western (V. pennsylvanica) species of Yellow Jacket exist with few variations in the yellow and black coloring.
General Adult Size (Length):
12mm to 16mm (0.47in to 0.63in)
Indentifying Colors:
yellow, black, white