Martie Young
Adams County Master Gardener
Little did I know when I chose the topic of wasps that I would also be learning about hornets, yellowjackets, paper wasps and cicada killer wasps. All hornets are wasps but not all wasps are hornets--the U.S. has no native hornets. We do have the European hornet which was introduced into New York in 1840 (I doubt that its introduction was intentional!). It looks like a large yellowjacket--about 3/4 to 1 1/2 inches long. This insect is found in the eastern United States, including all of Pennsylvania. They look like yellowjackets but they are not, yellowjackets are much smaller. Then we have the bald-faced hornet which isn't a hornet at all, but a paper wasp. It is easy to identify because it has black and white markings on its face and abdomen. Now that you are thoroughly confused, you can just remember these insects are not bees. They are in fact stinging
insects and their mechanism is much different from a bee's. Only the female bee can sting and the bee loses her stinger after she has done her dirty work and she then dies; wasps can sting multiple times--this means a whole lot more pain for the stingee!
Bees and wasps took separate evolutionary paths over 100,000,000 years ago. Bees are vegetarians, collecting pollen to feed their young and only, as noted above, the female bee can sting, while wasps and hornets are carnivores, feeding on other insects and scavenging. The nest of the bald-faced hornet is the huge, gray, basketball-sized nest usually found swinging high in a tree. You can't miss this nest--it is so distinctive but keep your distance--the hornets are known to be very aggressive especially around their nests. Paper wasps nest above or below ground. Paper wasp nests are usually constructed of paper made by the wasps and nests are frequently found underneath house eaves.
Walking along a trail in the woods can be dangerous--if several of you are in a single line, the last few people in that line may become prey of the yellowjackets in their in-ground nest that have been disturbed and they will let you know they are unhappy. This was an actual experience for me except that I was one of the lucky ones near the head of the single line and avoided getting stung. As a warning--be sure you are prepared with an epi pen or Benadryl in case this would happen to you. Snakes aren't the only scary things in the woods
Most wasps are social wasps meaning they nest together and they die off in the fall--all except the fertilized queen. The queen will overwinter in protected spots such as hollow logs, under loose tree bark or in a soil cavity and emerge in the spring to start a new colony. The first wasps to emerge will help build a new nest and care for the young insects. The queen is the only female who mates and lays fertilized eggs which develop into female workers or future queens. Unfertilized eggs become males: male wasps cannot sting and do not participate in colony tasks.
Wasps are usually brightly colored and include yellow, orange and red with the basic color scheme of black and yellow or white. The distinctive striped pattern of a wasp serves as a warning to birds and other creatures to keep away. Many other insects copy the color patterns of wasps; therefore flies, and bees can be more protected from bigger predators. Make no mistake--a wasp is a predator! Another way to identify wasps is that they have a very narrow waist or 'wasp waist'--bees are wider bodied, while bees are covered with hair--wasps are usually hairless. The hair on a bee serves as a pollen collector; flies have two wings while bees and wasps have four. Yellowjackets, hornets and paper wasps (Family: Vespidae) hold their wings folded lengthwise over their bodies like a jet.
The cicada killer has a terrifying name but in general doesn't sting unless it feels threatened. It looks most like a yellowjacket but much bigger; it has a yellow face, brick-red eyes and a black abdomen with yellow bands. True to its name it preys on cicadas which brings up the question - are wasps, et al good or bad? Cicadas can become so numerous that we humans are grateful to the cicada killer and other bad bugs that are killed by wasps. Adult wasps do feed on nectar which makes them almost accidental pollinators. Many yellowjackets are superb hunters of pest insects such as aphids, caterpillars, and flies that damage crops. They are also drawn to meat and sweets which they scavenge, especially in the fall as food becomes scarce. They are very likely to invade your picnic in the fall or your food trash. Don't swat them or act in an aggressive manner because they will protect their home.
We should be wary of hornets, wasps, and other stinging insects but unless there is imminent danger you should not kill them. If they have invaded your living space, there are humane ways of getting rid of them. Consider the time of year that they are discovered. If you find them living in your house in September or later, probably you can ignore them since they will die after the first frost. If it is the middle of summer, check the approved methods for getting rid of them (Penn State has a fact sheet). Once they are removed from your house, check for openings and be sure to seal them up so you don't get the same problem next year.
Happy pest-free gardening!
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