Smokybrown

Introduction

The smokybrown cockroach gets its name from its uniformly shining brownish black to dark mahogany color. This species apparently is native outside the United States. It is common in the southern states from central Texas eastward through North Carolina, but does occur as far north as Illinois, Indiana, and Iowa. It also occurs in southern California.

Recognition

Adults are about 1 inch to 1-1/4 inch long. Color uniform and shining, typically brownish black but varies from dark mahogany to black. Both sexes with wings extending beyond their abdomens, good fliers, and attracted to lights.

Nymphal first instar black, second instar dark brown; instars one to three with mesothorax pale/white but anterior and posterior margins dark, lateral areas of seond abdominal segment pale/white, antennae with four to five apical segments white but instars two to three additionally with about 10-15 segments of the basal fourth pale. Later instars reddish brown but with lateral margins, posterior margins of thoracic segments, and tip of abdomen darker, instars four to six with tips of antenna and about 10-15 segments of the basal fourth pale, but late instars with antennae uniform in color. Cerci broadly rounded laterally, length about four times width with widest segments about three times as wide as long.

Ootheca or egg capsule dark brown to black; usually more than 3/8 inch long with length more than twice width; subdivisional furrows not extending to midwidth; and with 10-14 eggs on each side.

Habits

The smokybrown cockroach is common outdoors in the South where it is found in habitats best described as protected, moist, dark, warm, and out of desiccating air flows. These conditions describe the environment of tree holes and other places such as ground cover, ivy and vines, loose mulch, woodpiles, and soffits/eaves of attics where there are moisture problems. Smokybrown cockroaches lose moisture through their cuticle more readily than other cockroaches. This is why they favor moist situations and show relatively little movement because of its resulting exposure to desiccating air currents.

They can enter structures by being brought in, but they usually enter at night via cracks and crevices through which light penetrates to the outside, light being an attractant to them. Because they are good fliers, they easily can enter via attic openings and commonly are found around eaves and gutters. Inside they can be found anywhere, including attics, but tend to prefer warm and humid areas not exposed to air currents.