Cooperative Extension Service  ________________________________________________ Institute of Food and Agricultural Sciences

The Asian cockroach is one of our newest visitors that most of us wish had just stayed home. The Asian cockroach is nearly identical in appearance to the German cockroach.  This relatively new migrant to our shores has been widely publicized and is considered a significant pest by the residents in infested areas.

The Asian cockroach was identified as a newly introduced species in 1986, when a heavy infestation was found in Lakeland, Florida. A second, more heavily infested area was identified in 1987 near Brandon and  Tampa. Since that time the Asian cockroach has spread to infest virtually all counties in peninsular Florida.

The Asian cockroach is a rural and suburban pest that mainly infests single-family, suburban houses and yards. It can be locally abundant outdoors and populations of 30,000 to 250,000 per acre have been found. The adults are strong fliers and readily enter the houses.

The Asian cockroach is almost identical in appearance to the German cockroach. In fact, entomologists believed it was an outdoor strain of the German cockroach in Asia. The main morphological differences between the Asian and German cockroaches are the shape of a groove in one segment (eighth) of the abdomen and a small gland in the males. The wings of the Asian cockroach are usually longer and narrower than those of the German cockroach. They extend beyond the tip of the abdomen and cover the egg capsule in the females. Asian cockroaches are lighter in color than most German cockroaches.

Adults take flight even during the day if disturbed. They can be readily seen in infested lawns and mulched areas. At dusk there is a frenzy of activity; They climb to the tips of grass and leaves and take flight. They are attracted to lights and light-colored surfaces or brightly lit surfaces, where they alight. Numerous adults have been seen at all heights on single- and two-story homes.

Asian cockroaches will invade any opening in a house, such as a lighted doorway or window. Once inside, they will crawl on an illuminated television screen and on walls while the lights are on during the evening. Because the peak activity period of Asian roaches coincides with most folks leisure time, the presence of the cockroach is obvious.

Asian cockroaches are also abundant in shaded areas with leaf litter or where there is ground cover. In wild habitats, the Asian cockroach is found in shaded areas of pastures, along shaded road sides in leaf mulch, in shaded areas of thick grass, and in ground cover of citrus groves. The adults have been found feeding on the honeydew of aphids on citrus trees, and on the flowers of other plants during the night.

The female Asian cockroach produces an egg capsule that has about 40 eggs. It is carried by the female until the young are ready to hatch. The nymphs mature to adults in about 6 to 7 weeks. From late May through early August, nymphs predominate and adults are rarely encountered. However, adults are abundant during the early spring months February through May and again in mid-August to October. The extension office has recently received a flurry of inquiries from local residents indicating that Asian roach populations have reached high levels in some parts of the county.

The feeding behavior of the Asian cockroach appears to be similar to other cockroaches, in that they are omnivorous. Like other species of cockroaches, they are capable of carrying pathogenic organisms. Considering their ability to produce large populations and their likelihood of entering homes, pathogens associated with animal droppings and soil microorganisms can easily be carried by this cockroach when it enters the home.  People sensitive to allergens of German cockroaches are also sensitive to allergens of Asian cockroaches.

Although the Asian cockroach is very susceptible to pesticides, acceptable control of this cockroach is difficult. Toxic baits applied to infested areas outdoors have provided the most reliable control.  Because the Asian cockroach can fly 120 feet or more in a single flight, large areas around a home require treatment. Even so, cockroaches in surrounding untreated areas may result in reinfestation.

Residual sprays around the perimeter of structures are usually ineffective because there are numerous infested areas in lawns, mulch, and wooded areas. Adults enter homes through windows and doorways, and immediately fly to walls, avoiding baseboards and typical German cockroach harborages which are normally treated with pesticides.

Wouldn't be nice if this exotic visitor just decided to go home? Good luck and good gardening.

Gene McAvoy is the horticulture agent with the Hendry County Extension Service.  Direct your horticulture questions to PO Box 68, LaBelle, FL 33975,  e-mail - GMcAvoy@mail.ifas.ufl.edu or phone 863-674-4092 or  863-983-1598.  You are also welcome to visit the Hendry County Extension Office at 225 Pratt Blvd., LaBelle.   Office hours are from 8:00 - 5:00.