Garden Corner – The Wood Roach

Kelly Jackson
Christian County Extension Office

The Wood Roach

 

Wood cockroaches live under loose bark, in cavities of fallen or dying trees, or in stumps. They are natives of moist woodland habitats where they feed on decaying organic matter. These cockroaches are accidental invaders in homes and buildings in and around wooded areas. They are especially active during their summer mating season.

Winged males can fly short distances. Outdoor lights can draw large numbers of them to homes and structures. Then they can gain access into the house by crawling under exterior door gaps, through open windows, gaps around pipe or electrical service, or through cracks and crevices.

While it looks like a “typical” cockroach, the wood cockroach has a pale, light white or transparent stripe on the outer edge on its thorax. It also behaves differently from the house-infesting roach species. Wood cockroaches are not secretive; they are active day and at night and usually don’t run when approached. They will wander about the house without congregating in any particular location, like a kitchen or bathroom. They are an annoyance but wood cockroaches don’t become established indoor pests because the air is too dry for them to survive for long.

While at times there can be many of them; they are a temporary problem so there is no need for extensive use of insecticides in the home. Cockroaches found indoors can be swatted and discarded or sprayed with an aerosol insecticide containing pyrethrins.

If you are finding wood cockroaches to be a chronic problem, try limiting outdoor light use, especially around exterior doors to avoid attracting the males. They prefer quiet, undisturbed moist areas such as heavily mulched or naturalized areas or stacked firewood. Reducing clutter and increasing light and air penetration makes these places less attractive for the insect. Also, install tight-fitting window screens and door sweeps to exclude wandering cockroaches and other insects. Sticky card mouse traps can be placed in these areas to trap wandering cockroaches near entry doors.

In severe cases, insecticides can be applied as a “barrier treatment” around the base of the foundation. Pay particular attention to door thresholds, garage and crawl space entrances, including foundation vents. Insecticide examples include carbaryl (Sevin), or any of the pyrethroid insecticides: bifenthrin (Ortho Home Defense Perimeter and Indoor Insect Killer), cyfluthrin (Bayer Advanced Home Pest Control Indoor & Outdoor Insect Killer), or permethrin (Spectracide Bug Stop).