Carolina Paper Wasp Vol. 5, No. 8

Carolina Paper Wasp

Polistes carolina

Order: Hymenoptera
Family: Vespidae

“We’ve got these big orange wasps hanging around the eaves of our house and when we go in the back yard they try to sting us!”  These are Carolina paper wasps and there are two big differences between these and our more familiar species of paper wasps.
 
First, they prefer to nest in some type of dark, enclosed area, such as inside the eaves of a building, in the inside corner of a dark, infrequently used shed or in a large pipe or similar void.  Those wasps you see hanging around the eaves are just the guards.  Watch closely and you will probably see more wasps coming and going into the eaves through some crack or hole.  The nests are usually located just inside the eaves or void and may contain dozens of wasps.

The second difference is that Carolina paper wasps tend to be more aggressive than other paper wasps.  Paper wasps such as guinea wasps and red wasps usually do not sting unless they feel their nest to be seriously threatened, either by some type of jarring or vibration or by someone approaching extremely close.  Not so with Carolina paper wasps.  Those guards hanging around the entrance to the nest site will attack with much less provocation, often flying out to sting someone who happens to walk within 10 feet or so.

Control: Of course, any time one deals with stinging insects there is always a chance of getting stung, so proceed with caution, and wear appropriate protective equipment.  Also be aware of fall and electrical hazards! Because most stinging insects are less likely to fly at night, working at night is one good way to reduce the potential for stings.  Hiring a professional pest control company is an even more effective way to minimize risks.
 
If you want to try to control these yourself, start by using one of the “long distance” wasp and hornet sprays, the kind that spray 10 to 15 feet or so, to eliminate the guard wasps.  You may even want to do this for several days to deplete the total number of wasps.  For nests hidden inside a void, you can then use an appropriate aerosol spray with an injector straw to inject spray into the void to target the nest.  This is the step where it is especially important to have appropriate protection and/or work at night.  Relatively few aerosol sprays come with an injector straw, but Bengal Roach Spray II, the one that contains 2% permethrin, is one example.  Permethrin is a pyrethroid insecticide that provides relatively long residual control but be aware that it does not kill as fast as the wasp and hornet sprays.  The final step is to repair and seal holes and cracks to prevent re-infestation.  Of course, if the nest is exposed, you can just spray it directly with the wasp and hornet spray. 
 
[Note, there are two very similar species of orange paper wasps: Polistes carolina and Polistes rubiginosus (formerly P. perplexus).]