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Photo: Curt Williams

September Pest of the Month Yellowjacket Wasps

In Texas we have many different names for different insects. This can make things confusing when trying to describe a pest problem or identify a pet.

Yellowjacket is a comon name that we use for more than one type of wasp. In general most people identify yellowjackets as wasps of yellow and black or dark brown color-usually striped.

True yellowjackets make closed paper nests. They can be found nesting in hollow trees, holes in the ground or any other hole or hollow area-they love to fill voids.

Many people mistakenly call a type of paper wasp "yellowjackets." They have similar coloration and make paper nests, but their bodies are much larger and the nest is never covered. Another paper wasp, a red wasp, makes the same type of nest. Paper wasps nests look like upside down umbrellas and usually hang from the eves of homes. In the picture at the left, notice that the "design" on top of the head is different from that of a yellowjacket.

True yellowjackets are small wasps (1/2 inch) and can be confused for bees. They are yellow and black with yellow and black striped abdomens. Yellowjackets can be easily irritated by lawn mowers, weed wackers or tractors, and will emerge from the nest in large numbers to attack the threat (you!). They can sting multiple times, and the sting is usually quite painful. Everyone reacts differently and you may have an allergy, or develop an allergy to yellowjackets even if you've been stung a hundred times before with no reaction.

To control yellowjackets, find their nest entrance hole. Once you have identified this, use an insecticide in a powder formulation and sprinkle about a tablespoon inside and around the edge of the entrance hole. Dusk is the best time to treat because the wasps will be more docile and less likely to attack. But always be cautious.

Dusts are more effective formulations because the yellowjackets self-spread the pesticide. When they enter the nest they pick up the dust and spread it to all their nest mates inside the nest. You may have to reapply the dust several times depending on the size of the colony. Look for products containing carbaryl, acephate, esfenvalerate, or permethrin.

More information is available in theExtension publication, Dealing with Paper Wasps and Yellowjackets L-1828, available at: http://tcebookstore.org/tmppdfs/20063325-L1828.pdf