Wood cockroach (Parcoblatta sp.)
Wood cockroaches include a number of species of Parcoblatta of which the Pennsylvania woods cockroach is the most common. Wood cockroaches are the only group of cockroaches that occur in Michigan that were not introduced from some other county. Wood cockroaches are usually only occasional invaders of homes and rarely breed indoors. They are usually either carried in with firewood or attracted by outdoor lights. Only males are known to fly and are most troublesome during the mating season (May & June) when they travel in large numbers. Wood roaches may also be found in rain gutters of homes, wood and leaf piles, and other areas where plant material accumulates and decays. Wood cockroaches feed primarily on decaying organic material. They are difficult to manage with insecticides inside the home because they originate outdoors. They are common in firewood, so woodpiles should be kept away from the house. Residual insecticide sprays (like Bayer Advanced Garden) around doors, windows, porches, patios and other areas near outdoor lights will help control males which readily fly to lights at night.
Be sure to read and follow all instructions and safety precautions found on the label before using any pesticide.