Michigan's wasps seem to suffer from a serious PR problem. They are frequently confused with bees in the garden, are greeted with screams of terror by children at the lakeside, and are mercilessly hunted by urban exterminators. In truth, while wasps may appear threatening to humans, they are integral to the Great Lakes ecosystem. They perform the valuable function of reducing pests, as Michigan State University's Agricultural Extension explains. Michigan's native Yellowjackets, Paper Wasps, Cicada Killers and Bald-Faced Hornets have recently been joined by exotic Wood Wasps, according to the USDA.
Twelve different types of Yellowjackets make their homes in the ground, bushes, house cavities, and even the nests of other insects in Michigan. Many Yellowjackets are scavengers, seeking protein and sugar from any source. This is what tends to make them a nuisance at late summer outings. As supplies become scarce, German, Eastern and Hybrid Yellowjackets begin scavenging meat and savory items from human food. These species, and the Old World Yellowjackets, can eat meat as well as sugar, but honeybees cannot. Old World Yellowjacket workers also prey on other insects, including caterpillars, beetle larvae and flies. Some of the larger colonies in wooded areas can be extremely aggressive when disturbed.
Their reddish antennae, flight habits and nest-building styles set Paper Wasps apart from Yellowjackets, according to the Michigan State University Extension (MSUE). Paper Wasps fly with their legs hanging down from their bodies. Their antennae have russet-colored tips. In contrast, Yellowjackets have solid black antennae and keep their legs tucked up against their bodies when they fly. According to MSUE, Paper Wasps will make their nest anywhere—many times in the eaves of houses. A single layer of paper-like cells provides all the shelter these wasps need. Most Paper Wasp stings occur when people accidentally disturb the nest, and both insects and human are surprised. The European Paper Wasp seems to be edging out other species.
The Cicada Killer Wasp nests directly in the ground and lives a solitary life compared to other species of wasps. According to the MSUE, this wasp has a rusty reddish color tone throughout its body. It gained its common name because of the way it feeds its young. After egg-laying, it stings and paralyzes a cicada, and drags it home to feed its larvae when they hatch. The MSUE further explains that every brood cell gets at least one cicada. Cells containing female eggs get two. Because the wasps prefer to nest in areas with sparse vegetation, fertilizing and watering of lawn and yard are usually enough to deter any infestations.
The Bald-Faced Hornet has a dramatic "pale-black-pale" marked face. While technically a Yellowjacket, this wasp also bears some similarity to Paper Wasps in the area of nest building. It makes a paper-like nest; however, its nests have many layers and a variegated grey sheath. Some can be as large as a football, according to Michigan State University's Agricultural Extension's "Cyberbee" resource site. The nests are most often located in trees and bushes, and rarely in house structures. This species tends to prey most upon a variety of other pest insects, which makes it a beneficial addition to gardens and in agriculture. Unless they are near the home or allergies are an issue, these wasps are best simply left alone, according to "Cyberbee."
The Wood Wasp bores into the trunks of dead or dying trees. It can become an invasive pest, causing the destruction of natural habitat. According to the USDA, It is possible that the insects trapped and identified in Michigan may have migrated from Ontario. In time, biological controls can be effective against this species, if they do not have unintended consequences. For more about invasive species, and how wasps can help, see the Resources section.