The Buzz About Paper Wasps

Common paper wasp (Polistes spp.)
Photo:  Russ Ottens, Univ. of Georgia

The cooling weather will soon bring an end to activity for Polistes or paper wasp colonies. There are

several species of paper wasps, but the common ones are brown in color with yellow stripes on their abdomens. The workers (who will die soon), along with next year's crop of queens, are starting to bail out of their nests. The surviving queens will seek out some place to pass the winter. All too often our houses, and other structures, become the location of choice.

You may begin seeing wasps outdoors hovering about the eaves and soffits on warm afternoons. At some point, the wasps may make their way indoors, and things can get more exciting. The wasps are often seeing moving about slowly and bouncing off windows, ceilings, light fixtures, etc. Cold weather seems to stop the activity, but quite likely on subsequent warm days you will find wasps flying about indoors or again spot them outside around the roof area.

A few things to keep in mind:

First - seeing the wasps does not mean that there is a nest in a wall; however, there may be a nest outdoors on a roof overhang, under a porch, in/on a tree or some other protected area.

Second - since these are queens looking for overwintering sites and not workers defending a nest, they are not aggressive and so stinging incidents are rare unless you have a "close encounter of the Polistes kind," such as I had when I laced up my running shoe one morning only to discover that a wasp had crawled inside there during the night.

Third - spraying indoors is an exercise in futility because there simply isn't a specific target area you can treat. Spraying the exterior of the building also has limited value because there are so many gaps accessible to the wasps.

Best advice: keep a rolled-up newspaper handy. Be patient; let the wasp land then smack it.

For further information about paper wasps, check out:

http://www.ces.ncsu.edu/depts/ent/notes/Other/note144/note144.html

http://insects.ncsu.edu/Urban/paperwasp.htm

Kudzu Bugs on the Move Again

Kudzu bugs aggregating on structure searching for 

overwintering sites (Photo:  Dan Suiter, Univ. of Georgia)

Kudzu bugs will soon be moving out of soybean fields, which means you may begin seeing them aggregating on or inside structures. The kudzu bug's fall movement indoors is very similar to what we've experienced since the 1990’s with the Asian lady beetle. The major difference between the two insects is that the Asian lady beetle is actually beneficial as a biological control agent because it feeds on aphids and other plant-feeding insects. By contrast, the kudzu bug's primary food source (aside from kudzu) happens to be field crops, such as soybeans, where they can significantly impact on yield. The kudzu bugs fondness for soybeans is one reason why we could see significant numbers of them invading homes and other buildings, even in rural areas. In more urban areas, there are plenty of other hosts, such as wisteria and privet. The insects are quite mobile; they are able to catch rides on wind currents, as well as automobiles, trucks, trains, and planes. This helps explain why this pest has managed to spread in about 4 years from the north-central Georgia to most of South Carolina, North Carolina and on into Virginia (plus west into Mississippi).

At this point, we still do not have anything new to report in terms of recommendations as to how to address this problem. Kudzu bugs are attracted to light-colored surfaces but that certainly doesn't mean that brick buildings or those with dark-colored siding will escape the bug invasion. While shortcuts and easy solutions would be nice, there simply aren't any.

The emphasis still has to be on exclusion because chemical control is only partially effective and relies primarily on targeting the insects that are aggregating on surfaces. Preventive sprays are not recommended because they simply won't be durable enough to last the weeks during which these insects will be actively seeking overwintering sites. If you feel a treatment is required, stick with targeted treatments of critical areas: windows and doorframes, soffits, and eaves. If you choose to treat using a pyrethroid insecticide, remember to follow new label requirements. For the latest label changes, visit:  http://www.epa.gov/oppsrrd1/reevaluation/environmental-hazard-statment.html.

For more information about the kudzu bug, please visit our website: http://www.ces.ncsu.edu/depts/ent/notes/Urban/kudzubug.htm