Here we are after Labor Day already. As summer winds down, some pests can become more of a nuisance, such as the yellowjacket wasp. However, remember that they are beneficial and care should be used before destroying them in mass.
Yellowjackets are 1/2-inch-long, black-and-yellow-banded wasps. They live in places such as underground nests, woodpiles, hollow trees or holes in the wall of a building. Late in the summer, nests may contain several thousand wasps. Of the Illinois bees and wasps, this is probably the most likely to sting. Yellowjackets are easily provoked and can sting more than once. They may attack in force if their nest is disturbed.
Many people wonder why they seem to see so many yellowjackets “all of a sudden”. But, actually they build up in population throughout the summer. Late in the summer, nests may contain 1,000 to 5,000 workers and may measure three to four feet in diameter. Most of the insects die over the winter and only queens survive. Her first new adult generation emerges about June.
Yellowjackets often congregate near places where food and drinks are served such as backyard decks, picnic facilities, or other gathering places, which makes them more noticeable. In late summer and fall, these locations can have extremely high populations, since the population is higher and there are fewer other natural nectar sources available.
They are also attracted to open cans of garbage, bright flowery clothing, and floral scented perfumes. Garbage cans should be kept clean and well covered to help reduce problems. The elimination of overripe fruit from gardens and orchards can decrease the number of scavenging yellowjackets.
Reducing attractive situations around the home can lessen the problem. In situations where the potential for repeated human contact exists, chemical control can be effective. However, remember these are beneficial insects. They help reduce damaging pests by feeding on them. So use pesticides only when really necessary, judiciously and carefully.
• John Church is the Kendall County program director at The Conservation Foundation.