Don't stir up a hornet's nest

Earlier this year, the Asian killer hornet was the big news item after it was discovered for the first time in the U.S. Since this discovery, the state of Washington has taken steps to eliminate this new invasive species. It is unlikely the Asian killer hornet will become established in Ohio because our winters will take it out. However, Ohio does have hornets. This time of year, the nests of the native baldfaced hornet are large enough that hikers and homeowners notice their artistic nests hanging from trees and buildings. Baldfaced hornets are members of the wasp family (Vespidae) that also includes wasps and yellow jackets. They are large (about three-quarter-inch long) and have black with white markings on the front of the head and abdomen tip. Hornets are much more common in southern Ohio than in northwest Ohio. However, their hot air balloon-shaped nests may be found in woodlots, yard trees and occasionally, eaves of buildings in our area. In the spring, queens emerge from their over-wintering sites (not the old nest) and select suitable locations to build new nests. They construct paper nests by using their powerful mandibles (jaws) to first scrape fibers from exposed wood and then mix the fibers with their saliva. The resulting paper extruded from their mouths is lightweight but strong and water repellent. The paper may also be multicolored, reflecting variable sources of the wood fibers. A nest will continually be enlarged to accommodate the growing population of hornets. It may exceed the size of a basketball and contain about 700 adult hornets by the end of summer. Most individuals will want to remove the nest when near areas of human activity, since hornets will aggressively defend anything that approaches the nest. Each nest has sentries at the nest and in nearby branches and structures to act as first protectors and warn the colony of a potential threat. Each adult baldfaced hornet can sting multiple times. It also has a different stinging behavior compared to wasps and yellow jackets. Wasps and yellow jackets will generally land on an individual before it stings. However, the hornets do not land first — they fly at their target at full speed and just before they reach the target, tuck their abdomen so their stinger is pointing forward. They literally drive their stinger into their hapless victim. People often describe their sting as a very painful experience. Some individuals are allergic to the venom of hornet and other wasps. However, if you are allergic to wasps, that does not necessary mean you are also allergic to the bee family or vice-versa. I have been stung enough times by bees, wasps and yellow jackets (fortunately not hornets) that I know I am allergic to the wasps but not bees. Bumblebee stings are still painful to me, but they do not cause the hives and asthmatic symptoms that occur from wasp and yellow jacket stings. It can be difficult to identify whether the insect is a member of the wasp or bee family. Wasps generally have a thin waist appearance between the abdomen and thorax (middle insect body section). When resting on a surface, wasps will pull their wings along the body and bees will have their wings sticking out. Bees also tend to be hairy (particularly honey bees, which are covered with short, fuzzy hair) and wasps are not hairy. Baldfaced hornets are considered beneficial insects, despite their painful stinging behavior. Like other yellow jackets and many wasps found in Ohio, hornets are highly accomplished predators. They hunt soft-bodied insects including caterpillars and sawfly larvae and use their powerful mandibles to grind up their victims into insect puree. The insect-mush is fed to the grub-like larvae housed within the nest. As a result, a hornet's nest can have a considerable impact on the local caterpillar pest population including bagworms (the bags offer little protection from the hornet's mandibles). Thus, efforts to control hornets should be limited to nests that present a clear and present danger to homeowners. Control may be necessary if hornets establish a nest near areas of human traffic. Control treatments may be found at https://entomology.ca.uky.edu/ef620 and https://entomology.ca.uky.edu/files/efpdf3/ef600.pdf Care should be taken in removing hornets and may require a professional. Lack of caution may quickly remind you why the phrase "stirring up a hornet's nest" is part of everyday language. Baldfaced hornet colonies only last one season in Ohio. The workers and old queens in the current season's nests will freeze to death during the winter and the current season's nests will never be reused. Individuals may want to collect old nests to display a part of nature's wonders and to be used as a talking point. Nests may be collected after a hard freeze has killed the present year's population. Information on how to preserve and display a hornet's nest can be found at http://www.ipm.iastate.edu/ipm/info/articles/preserving-and-displaying-hornets-nest. Pictures and more information on hornets may be found at https://bygl.osu.edu/index.php/node/1671 Lentz is Extension educator for agriculture and natural resources for the Ohio State University Extension Service in Hancock County.