Nevada’s yellowjackets are out and about

I was out watering a few days ago and I noticed yellowjacket wasps crawling on the ground. I mentioned to my friend Will that I thought yellowjackets bite rather than sting. He said he didn’t think so, saying not only did they sting, but they could sting repeatedly. Well, he was right, but so was I. They sting and bite. Sometimes they bite to get a good hold to allow them to sting more efficiently. Since they don’t leave their stinger in your skin like a honeybee does, they can sting over and over.

They nest in old rodent burrows, in holes in the ground, in logs, in building walls, in attics or even under shingles on a roof. They also may build aerial paper nests under eaves or in trees, similar to those of the less aggressive paper wasps. “Colonies, which are begun each spring by a single reproductive female, can reach populations of between 1,500 and 15,000 individuals, depending on the species” (University of California, Davis Integrated Pest Management).

Yellowjackets only live one season, except for the fertilized queen who overwinters. They are black with bands of bright yellow and a pronounced “waist.” According to UCDIPM, you want to get away quickly if wasps start stinging. Multiple stings at one time can introduce dangerous quantities of wasp venom. In large amounts, the enzymes in the venom can cause blockages in the kidneys leading to possible kidney malfunction or failure. However, even one sting can be quite painful if you are sensitive or very problematic if you are allergic. A sting can cause swelling, often much larger than a mosquito bite, and it can itch and burn at the same time. Putting ice immediately on a sting can reduce discomfort.

There is no doubt that yellowjackets can be pugnacious pests especially around food or in defense of their nest.

“In fall, foraging yellowjackets are primarily scavengers, and they start to show up at picnics and barbecues, around garbage cans, at dishes of dog or cat food placed outside, and where ripe or overripe fruit are accessible. At certain times and places, the number of scavenger wasps can be quite large” (UCDIPM). They are particularly aggressive as food sources get scarcer in the fall.

Although yellowjackets are annoying to humans and animals, they are actually beneficial insects preying upon a variety of insects. For information: http://ipm.ucanr.edu/PMG/PESTNOTES/pn7450.html.

On another note, please donate your excess fall fruit or veggies to The Greenhouse Project. Call 775-600-9530.

JoAnne Skelly is Associate Professor & Extension Educator, Emerita, University of Nevada Cooperative Extension. She can be reached at skellyj@unce.unr.edu.