Wood Cockroaches

Now is the time when homeowners will notice medium-sized cockroaches wandering about the house in the middle of the day. These are usually wood cockroaches, also known as wood roaches.

Wood roaches are similar in appearance to the household cockroaches, but they live exclusively outdoors. They live in rotted logs, tree stumps, hollow trees and under the loose bark of dead trees and firewood. They are especially noticed at this time when the males are active and attracted to lights.

Once indoors, wood roaches wander during the daytime rather than at night like the household roaches. They die within a few days of their accidental invasion into the house because of insufficient moisture. Wood roaches do not reproduce or establish indoors, and their presence is only an annoyance. They do not harm the house structure, furnishings or occupants.

Wood roaches can usually be identified by the presence of white stripes on the edges of the thorax and front portion of the wings. This characteristic is more readily apparent in the slender, straw brown-colored males than in the dark brown females and nymphs. The wings of the males extend slightly beyond the tip of the abdomen. The females wings cover only half of the abdomen, and nymphs are wingless.

The sprays and dusts used with success against household cockroach species are of very limited benefit against wood roaches. Exclusion techniques that prevent wood roach entry should be considered. Doors and windows should be tight-fitting and cracks, gaps and other possible entry points should be sealed. Outdoor insecticide barrier treatments of diazinon, Dursban, malathion or Sevin around windows and doors and along the foundation or firewood pile are a last resort that may reduce the number of wood roaches that get indoors.

Wood Roach (Parcoblatta spp.)

This article originally appeared in the May 25, 1994 issue, p. 81.


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