LSU AgCenter's Weekly Message

Paper Wasps: Arguably Good Gals, Usually

A recent encounter with paper wasps inspired me to learn more about them. I sat down on my porch to read and went back inside the house to get something. On my return, an insect stung me on the nose just as I sat down. I didn’t see any nests or even the culprit itself. I went back in the house to get a fly swatter. When I came back out again, the as-of-yet mystery insects got really unhappy, and several stung me on my shoulder. Shortly afterwards, I realized that the nest was in the light fixture next to my front door.

Paper wasps (Polistes spp.) are not particularly aggressive stingers. In my case, the repeated opening and closing of the door close to their nest probably was a bit too much for them, hence the stings. Most of the time, we might regard paper wasps as beneficial. They prey on caterpillars, including pest species.

Paper wasp nests have a honeycomb-like appearance with multiple cells in which the female that started the colony (the queen) lays her eggs, placing one egg in each cell. After the eggs hatch, the mother feeds pre-chewed caterpillars and other insects to the larvae for a while and then covers the cells. Juveniles pupate and emerge from the cells as winged adults. Most of the wasps in a colony are females, while males develop in the fall for mating.

Nests become uninhabited over the winter and are not reused by paper wasps. The mated females that will start the next season’s colonies spend the winter in protected spaces.

If you do end up with a paper wasp nest in an unacceptable place, you can use one of the aerosol wasp and hornet sprays. Most of these contain one or more of the pyrethroid insecticides (active ingredients with names ending in “thrin,” with a few exceptions). Be sure to follow label directions when using any insecticide.

Since paper wasps aren’t aggressive, you may be able to achieve adequate spray coverage of the nest and the individuals on it during the day, from several feet away, without being stung. Wearing protective clothing (long sleeves, pants, etc.) is suggested. To reduce the risk of being stung, you can spray in the evening when the wasps are less active. If you do this, avoid turning on lights or bringing a flashlight.

Since paper wasp nest construction begins in the spring and the number of wasps increases over the season, it’s better to get rid of them earlier than later, if they’re in a problematic location. If you do it early enough, you might be able to just knock the nest down with a broom.

Let me know if you have questions.

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Dr. Mary Helen Ferguson is an Extension Agent with the LSU AgCenter, with horticulture responsibilities in Washington and Tangipahoa Parishes. Contact Mary Helen at mhferguson@agcenter.lsu.edu or 985-277-1850 (Hammond) or 985-839-7855 (Franklinton).