As we head towards Labor Day and the unofficial end of summer, people are noticing some our different species of stinging insects. The inquiries we have received have all focused on these insects being Asian giant hornets (aka the “murder hornet”), an insect not known to occur in the state. Thus far, that species has only been found in the Pacific Northwest.
What we do have in Kentucky are things like yellowjackets, paper wasps, and European hornets. Some of these are aggressive in their own right, and others do resemble the Asian giant hornet. Here are some tips on identification and advice on managing these insects, if necessary.
Yellowjackets are some of the most encountered stinging pests. These bright yellow and black-colored wasps are usually around a half inch long. The workers of a colony are the ones we encounter most often. In the earlier part of summer there are fewer workers, and they are on the hunt for meat, which they can obtain as prey items such as caterpillars or as scavenged material from garbage and roadkill.
Yellowjackets build papery, football shaped nests in the soil or in shrubs and occasionally trees. These nests expand over the course of the summer and by the end of the growing season can commonly contain thousands of workers. The workers switch from looking for protein to looking for more sugary materials. This means fruit, pop, fruit juices, and frozen treats. These workers and the original queen will all die when winter sets in though. Only new queens produced by the original will go into the next season to produce the next round of nests. The switch in diet and need to protect the new queens can mean more encounters with humans and an increased defensive nature when nests are discovered.
There are several paper wasp species that can be encountered. They tend to be 1/2 to 3/4 inch long and have smoky-colored wings that you can’t quite see through. Some species are brownish, others red, with some being black and yellow. One of the more common species, the European paper wasp, has coloration that looks very similar to a yellowjacket except their antennae are orange at the tips.
Paper wasps get their name for building umbrella-shaped nests that are constructed out of paper they make by chewing wood scrapings into a pulp. These nests are often found on trees, shrubs, eaves of homes, rafters, railings, and other semi-protected areas. Paper wasp nests don’t get as large as other stinging pests and as a group they tend to be less defensive of the nest than things like yellowjackets. They will sting though, and it can be quite painful. The nest is annual and the insects will die out by fall, with new queens produced overwintering to found their own nest the next season.
This species is the one that has been most confused for the Asian giant hornet. They are also a non-native species, but are slightly less famous than their larger cousins from Asia. Workers of this species are around an inch long, with queens reaching 1 1/2 inches in length. They have a pattern on their abdomen that resembles a yellowjacket’s and is also black and yellow. Their thorax and head are a mix of yellow with patches of dark red, which helps to differentiate them from the Asian giant hornet as well.
They build large paper nests that they will defend by stinging. These large insects are predators; they will consume almost anything they can catch and will eat honey bees (though not quite as aggressively as the Asian giant hornet). They are also known to steal prey from spider webs to eat for themselves. One other interesting feeding habit they demonstrate, in the fall, the workers will girdle tree branches and small trunks and then drink up the sugary material that leaks out.
Management of Stinging Insects
If folks are dealing with a nest of stinging insects, they should consider contacting a professional to help them eliminate the problem. Of course, that might not be feasible for some, so it is important to note the ways that these pests can controlled by homeowners on their own.
First and foremost, they will need to discover the entrance to the nest. Treating individual workers will not eliminate the problem.
Once the nest or entrance has been discovered, an aerosol wasp and hornet product (examples include Raid and Spectracide Wasp and Hornet) can be applied into and onto the nest. These are quick acting products, often needing just seconds to eliminate the nest. The application should be done at dusk or after dark to maximize control and minimize the chances of being stung. The person making the application should also have an escape route planned in advance and a place of safety to retreat to, just in case.
By Jonathan L. Larson, Entomology Extension Specialist