There are many species of wasp—yellow jackets, paper wasps, hornets, mud daubers, spider wasps, and cicada killers—and all are beneficial by virtue of their predatory habits. However, since these insects are capable of stinging, they can present a considerable nuisance as well.

Wasps can be divided into two groups based on their habits. Social wasps construct small- to large-sized nests of gray paper that may contain 50'5,000 individuals. Solitary wasps are not colonial, and they nest in the ground or in tubular mud nests.

Solitary wasps also differ from social wasps in their nesting habits and lifecycle. Solitary wasps have no worker caste so the queens care for their own young. The queens use their sting to paralyze prey (flies, caterpillars, spiders, etc.) rather than to defend their nests. Solitary wasps are therefore non-agressive toward humans and rarely sting unless touched or caught in clothing.

Two species of solitary wasp are most frequently encountered—mud daubers and cicada killers. Mud daubers are medium- to large-sized, shiny black or metallic blue-black wasps with slender abdomens. They build finger-like nests of mud usually attached to flat, vertical surfaces. The queens provision their nests with paralyzed prey and then leave the young to develop on their own.

Control can be achieved by killing the offending adult wasps with a fly swatter or wasp or hornet aerosol spray (most contain resmethrin and/or pyrethrins). Remove and destroy the mud nests to prevent emergence of the developing young.

Cicada killers are large (1 1/2 inches or longer) with dark brown bodies and black abdomens that have yellow markings. They are ground nesters that prefer sandy or other well-draining soils into which the queens dig tunnel-like chambers.

The adults are active in the summer, usually after early July. They are frequently seen flying about in the nesting areas. The queens search for cicadas to provision their nests, hence the name.

Each chamber in the nest (often as many as 16) is supplied with a paralyzed cicada and a wasp egg. When the larva hatches, it feeds on the cicada. Later, the larva pupates and the wasp hibernates in the nest as an immature adult.

These wasps are large but non-agressive, although they do have a potent sting. Locate the nests during daylight hours (they are easily spotted because of the large amounts of soil excavated from the nests) and mark them so you can find them at night. All insecticidal treatments must be done late at night or in the pre-dawn hours when the wasps are in the nests and when it is cool (preferably less then 60 degrees F.).

Use a flashlight covered with red cellophane for lighting. Apply an insecticide (carbaryl 5% dust works best) into each nest entrance and then fill the hole with a handful of moist soil.

Courtesy MSU Extension