All You Ever Wanted To Know About The Ground Hornet
The ground hornet, also known as the cicada killer wasp, is a large and intimidating looking insect. Although they are one of the largest types of wasps and are known for attacking and killing cicadas, ground hornets actually rarely present a danger to humans. Their sting, like that of any wasp, is painful and can cause an allergic reaction, but the cicada killer preys specifically on cicadas and has little interest in bothering humans unless bothered first. Their underground nests, however, can be irritating and unsightly when dug on your lawn. If they build their burrow in a high-traffic area, there is a greater chance that you will bother the insects and risk getting stung.
The cicada killer wasp generally grows to a length of 1.5 to 2 inches, making it one of the largest of all wasps. Rarely, a ground hornet can grow to be 4 inches in length. The insect is generally mostly black or rust-colored, with yellow markings. Although it looks a bit like a yellow jacket, it is larger in size and an entirely different species. In the United States, the most well-known species of ground hornet is the Eastern cicada killer, but at least 22 species of the wasp exist in the world.
In preparation for laying her eggs, the female wasp burrows into the ground, creating a nest that can be up to 4 feet deep with several branches and many cells for individual fertilized eggs. As its name suggests, the ground hornet always creates its nest as a burrow in the ground, unlike other wasps that build their nests from tree branches or under eaves. It prefers to burrow in sandy and well-drained soil, and will generally avoid a yard with a lush blanket of grass. A burrow will be marked by a mound of soil from the hollowed-out nest, and can also be recognized by the presence of the wasps themselves. Unlike social wasps, which present a large danger by their ability to mobilize the entire nest in attack, the ground hornet is a solitary creature. The male wasps can be quite aggressive toward each other and humans that they perceive as a threat, but do not have stingers and do not pose much of a danger.
While less aggressive toward animals than their male counterpart, the female ground hornet has a stinger and is capable of a very painful sting. Luckily for humans, she directs this sting almost exclusively to her prey of choice, the cicada. When it finds a cicada on the trunk or lower tree limbs, it stings the cicada and paralyzes it. Once the cicada is paralyzed, the female wasp turns it onto its back and carries it back to the nest, where it will provide nutrients for the female's eggs. Each cell of the nesting burrow is filled with one or more paralyzed cicadas, sometimes up to four per cell. The female wasp then places a single egg in each cell, which is then sealed off. It appears that the ground hornet can tell which eggs carry female wasps, as they are generally placed with the largest amount of provisions.
The egg hatches a few days later, and the larvae feed on the cicadas provided by the mother wasp. When only the cicada's shell remains, the larvae spin a silken case of up to 1.25 inches long, and pupate throughout the winter and spring. The adult cicada killer will emerge in the summer, and the process will begin again with the next generation of cicada killers.
Depending on where it nests, the cicada killer wasp can be a pest to humans. However, it generally doesn't pose much of a threat, and can even be beneficial by ridding the yard and garden of troublesome cicadas. As with many creatures, if you do not bother the ground hornet, it will not bother you.