Spring Means the Appearance of Stinging Insects – May 2009
As the temperature warms, we will soon see paper wasps actively constructing nests. There are two species of paper wasps, Polistes exclamans which is brown with yellow markings on the head, thorax and bands on the abdomen and Polistes carolina which is reddish-brown in color. Both have smoky colored wings and are ¾ to 1 inch in length.
In the spring, the fertile queens find a nesting site and begin to build a nest. Paper wasp nests are composed of wood fibers that are chewed and formed into open hexagonal cells arranged in a comb-like shape. The female will lay a single egg inside each nest cell. Their nests are oriented downward and are suspended by a single filament. Their nests can be found in such areas as underneath eaves, in structures, or around plants. Adult paper wasps prey on insects such as caterpillars, flies and beetle larvae, which they feed to developing larvae. This makes them a beneficial insect.
Some Control Options
Since paper wasps feed on caterpillars and other insects, they are considered beneficial insects and no control is needed. However, some people may be highly allergic to their venom, so removal of the wasps nest is necessary. Nests can be knocked down from eaves using a high pressure water spray.
Chemical Control Options
Also pressurized sprays of insecticidal soaps and oils can be used. Residual insecticides can also be used, such as those containing the active ingredients deltamethrin or cyfluthrin.
Be sure to take precautions when treating, so the wasps will not attack nearby people or pets.
Another stinging group of insects that might cause alarm in areas are swarms of bees. Swarms of bees occur most commonly during the early spring when new queens decide to form a new nesting site. These bee swarms are less likely to be aggressive so we usually do not have to worry about stinging. However, these swarms tend to cause uproars in urban areas, if the nest settles in a backyard tree or on a porch. Also if the bees find a way to invade structures and take up residence in walls or attics, it could lead to a pretty expensive removal. If nests are not removed, the wax, honey and dead bees may produce odors that can attract other pests such as mice, ants, or cockroaches.
Some people prefer to leave their wild bee swarms alone. However if you wish to take action, the safest course is to hire a beekeeper to remove the swarm or hire a professional to eliminate it before they discover a way into structures. For more information about bees, please visit http://honeybee.tamu.edu.
Mention of commercial products is for educational purposes only and does not represent endorsement by Texas AgriLife Extension or The Texas A&M University System. Insecticide label registrations are subject to change, and changes may have occurred since this publication was printed. The pesticide user is always responsible for applying products in accordance with label directions. Always read and carefully follow the instructions on the container label.