The aggressive wasps known as Yellow Jackets are carnivorous, and can be menacing creatures when it comes to a showdown over the picnic table. They are often mistaken for bees, and sometimes are even called “meat bees,” but wasps are more closely related to ants than to bees. In the late summer and fall, their populations increase to full colony production levels.
western yellow jackets
These social hunting wasps (Vespula pennsylvanica) are responsible for most stinging incidents. Their mouthparts are well-developed with a proboscis for sucking nectar, fruit and other juices, and strong jaws called mandibles for capturing and chewing insects. Barbecued meat with sweet sauce is a prize! Unfortunately for us, these insects are just as likely to try to saw off a piece of your flesh as they are to sting you. If they do sting, they don’t leave a stinger, so they can sting repeatedly.
Like other social wasps, Yellow Jackets establish a new colony each year, which they abandon completely in the fall, when all but a few fertilized queens die off. These queens find a secure place to become dormant over winter, then revive in spring to establish their new colony.
The queen begins a paper nest from masticated wood pulp, and conceals it in an abandoned underground nest, in trees, shrubs, or in protected places such as inside human-made structures. Here she lays her eggs to produce the workers that will enlarge the colony.
From spring to mid-summer nests are in growth phase, and the larvae require large amounts of protein, all supplied by the workers. They seek other insects, and scavenge protein-rich foods. By late summer the colony grows more slowly, and workers seek sugar to maintain the queen and the other workers.
controlling Yellow Jackets.
Yellow Jackets seldom sting when they are foraging, unless they are threatened or squashed between clothing and skin. They are likely to attack when their nests are disturbed by a direct blow or by vibrations, so control should involve an Integrated Pest Management (IPM) approach using non-toxic products, avoidance, prevention and care.
Using pesticides to control Yellow Jackets is not recommended. Not only are pesticides harmful to the environment, but to be effective, the entire Yellow Jacket colony, and sometimes multiple colonies, must be located and destroyed completely. Poisons can rarely reach an entire nest.
Spraying a mix of peppermint oil, dish soap and water at the mouth of the Yellow Jacket nest can work to deter them.