Yellowjackets have been around since spring, but if you are going to get stung, this is the likeliest time for it to happen. One got me in the tip of a finger a couple weeks ago when I made the mistake of picking the peach it was sitting on.
Yellowjackets are members of the wasp family Vespidae. They are small black and yellow wasps about the size of honeybees - if there is actually anyone out there who doesn't know what they look like.
They are social insects that live in colonies, and that is precisely what makes them become problems in late summer and fall. The colony consists of a queen, her adult offspring (workers) and her eggs and larvae.
Earlier in the year, yellowjackets mostly mind their own business, unless you happen to disturb their nest. They make paper nests out of chewed wood fiber. The nests are usually hidden, but occasionally you can find them hanging in bushes and trees.
They often build nests in the ground in the abandoned burrows of small animals. This causes unpleasant encounters with yellowjackets if you mow over the opening to the nest hole and hundreds of defenders boil out.
They nest in hollow trees, in chimneys, between walls and similar places. My mother-in-law had yellowjackets nesting in a concrete block of her garage foundation. They had found a crack in the wall that let them in to build there. I found a nest in a hollow, rotten railroad tie around my garden while I was weeding. Ouch!
All that said, yellowjackets aren't particularly aggressive earlier in the year. That is because they are extremely busy. First, they must gather and chew wood to build a nest. Then they must maintain the nest, tend the eggs and feed and care for the larvae all season.
Larval yellowjackets are meat eaters and eat live prey that the workers bring them. This means that the workers are highly beneficial during feeding season because they capture thousands of caterpillars, grasshoppers and other insects that damage crops and gardens. The workers mostly feed on nectar but do eat some meat.
As the growing season winds down, the yellowjacket queen stops laying eggs and eventually dies. The remaining larvae grow up, and the workers soon have no work to do. As with many humans who have no meaningful work, the idle workers spend their time hanging out and getting drunk on fermenting fruit!
There is plenty of overripe fruit on trees, on the ground and at farm stands. There are dumpsters full of rotting garbage. There are people picnicking.
Yellowjackets like the same things that people like. They love beer, wine, soft drinks, fruit juice, ice cream, sweets, meats, dips, cheese and all the other goodies found at outdoor gatherings. They will home in on any uncovered food and they will follow people who are eating. Like many humans who overindulge, drunken yellowjackets are aggressive and will return again and again when you try to shoo them away.
They often crawl into unguarded beverage cans and bottles - which can result in a sting on the lip or even in the mouth of an unsuspecting person who takes a drink. I can't emphasize enough how dangerous it is to give a small child a "sippy cup" of a sweet beverage outdoors when yellowjackets are around.
All of the yellowjacket workers will die in fall, after a couple of hard frosts. The only survivors will be new young queens who have already been fertilized. They will find protected places to spend winter. In spring, each young queen will start her own nest, lay a few eggs and take care of her young until they are old enough to become workers.
In the deep south, yellowjacket colonies do survive winter and enlarge their nests until they are quite huge. Climate change and milder winters could cause that to happen here in the future. In the meantime, enjoy your outdoor gatherings but be sure to guard your food and drinks.
- Send your insect questions to Claire Stuart by email at email@example.com or write her (with self-addressed, stamped envelope) in care of Living Section, The Journal, 207 W. King St., Martinsburg, WV 25401.