F@stSheet Ent-1034

The Cricket Hunter Wasp: An Unusual Pest IN THIS F@STSHEET IDENTIFICATION DAMAGE CONTROL YOU CAN HELP FOR MORE INFORMATION

Liris beatus (Hymenoptera: Sphecidae) is a small solitary wasp that occasionally becomes a pest in Texas homes. Known as the cricket-hunter wasp because of its habit of catching and feeding crickets to its offspring, these wasps are common outdoor insects.

IDENTIFICATION

Cricket-hunter wasps are ½ - 5/8 inches long, dull black in coloration, with grey or dusky-colored wings. They spend much of their time searching for crickets, which they attempt to sting, capture, and transport live to their nest. After a cricket victim has been subdued and carried to suitable shelter, the female lays on it a single egg. After hatching, the larva begins feeding immediately on its paralyzed cricket prey. One cricket probably provides enough food for a single wasp to develop.

DAMAGE

Cricket-hunter wasps can be found actively climbing up and down walls of bathrooms and other living areas. They can appear indoors year-round, but are most common in late summer, fall, and during warm spells in the winter. Infestations can be persistent and annoying. Though not normally aggressive, when prompted these insects occasionally sting.

So what are these wasps doing in homes? In nature, female cricket-hunter wasps take advantage of openings in the ground, such as rodent burrows, for establishing a nest. In urban areas these wasps appear to take advantage of cavities in the walls of buildings, such as weep holes in brick facings or other openings in walls or under house foundations. A single female may deposit several crickets, each with egg, in a nest site. In addition, other female wasps may share the same site. Upon completing development, a process that may take several weeks, adult wasps emerge and attempt to exit from the nest area. If nests are located in walls, or under the foundation of a home, the wasps may emerge indoors through gaps around windows, air vents, or similar wall openings.

Because many crickets may be provisioned within a wall void in the manner described above, many wasps may emerge indoors in the same vicinity, giving the false impression that a large colony, like a bee's nest, is present in the wall.

CONTROL

It is difficult to prevent adult cricket-hunter wasps from emerging into a building once nesting sites have been established in a wall. The best solution is long-term prevention. Seal outside openings that might provide access to wall voids. Ventilation holes, such as weep holes, should be screened with 1/8th inch or finer mesh screen. Cracks and gaps should be sealed with expanding foam, mortar, or other appropriate material. In severe cases, wall voids may be treated with pesticide aerosols or dusts; however insulation-filled walls, and ignorance of the exact source(s) of the infestation, make this solution impractical in most cases. If openings through which wasps enter living areas can be located, they should be sealed. Adult wasps can usually be safely killed with a fly swatter, or captured and released outdoors to continue their worthy pursuit of crickets.

YOU CAN HELP

Little is yet known about cricket hunter wasps as indoor pests. If you are outside the Dallas-Fort Worth area and have wasp infestations fitting the description in this fact sheet, the author would be interested in obtaining samples of the offending insects and any observations about its behavior. Contact the address below, or call 972-231-5362. Samples should be sent in ethyl or rubbing alcohol with the location and date collected. Your help is greatly appreciated.

FOR MORE INFORMATION
For more information about stinging wasps see the Extension publication L-1828, Wasps and Yellowjackets For more information about arthropods, check out the Texas A&M Entomology Website at http://insects.tamu.edu

Authors:
Michael Merchant, Ph.D., Urban Entomologist, Texas AgriLife Extension

Publication information:
This publication is part of the House & Landscape Pest Series produced by the Department of Entomology, Texas A&M University, College Station, TX 77843-2475. The most recent update can be found at: http://dallas.tamu.edu/insects/Ent1034.html . Series Editor: M. Merchant.
Last revised: 9/6/01