The Australian Cockroach, Periplaneta australasiae¹

D. R. Suiter and P. G. Koehler²

APPEARANCE

The Australian cockroach closely resembles the American cockroach , but can be separated from it by its slightly smaller size (over one inch), the yellow margin on the thorax, and the light yellow streaks on the sides at the base of the wings or tegmina. It is about 1 1/4 to 1 3/8 inches long and the wings of both sexes cover the abdomen (Figure 1). The female has a broader abdomen than the male and lacks styli. Late instar nymphs possess distinct bright yellow spots along the margins of their abdomen.

American cockroach.

Figure 1.

HABITAT

This world-wide species has become established in the southern U.S. and in many greenhouses. In the United States, it is most abundant in Florida and the coastal southern states, and in California it ranges as far north as San Francisco.

Like the Smokybrown cockroach, it lives outdoors around the perimeter of houses and is the most prevalent cockroach outdoors in south Florida. Australian cockroaches are prevalent in leaf litter, in and around shrubs, flowers and trees, tree holes, wood piles, garages, crawl spaces, attics, and greenhouses. It is a pest when it enters homes where it may eat holes in clothing and feed upon book covers. It is apparently more vegetarian than the others, and in the northern U.S., it has appeared in greenhouses and temporarily becoming a dangerous pest.

BIOLOGY AND HABITS

The Australian cockroach life cycle requires about one year from egg to adult. The ootheca takes 40 days to hatch. There are 24 eggs per egg capsule, 16 of which hatch. Each female produces 20 to 30 oothecae. Nymphs take about one year to develop. Some eggs produced parthenogenetically hatch, but the nymphs do not mature.

CONTROL

Because the Australian cockroach is found outdoors, applications of insecticides to foundation plantings, wood piles, mulch, and other infested locations are recommended. Treatments placed to intercept cockroaches are both environmentally- and entomologically-sound. Residual barrier sprays have been shown to provide substantial reductions of Australian cockroach populations around houses. Power dusting of sewage lines, crawl spaces, false ceilings, wall voids, and trash chutes is an effective method of control. Space sprays, ULV treatment, or contact aerosols and sprays can be used in basements and utility rooms. Loose baits and other formulations better suited for damp locations can provide effective control in basements and similar areas.

Footnotes

This document is ENY233, one of a series of the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date October 1991. Reviewed May 2003. Visit the EDIS Web Site at http://edis.ifas.ufl.edu.

D.R. Suiter, research assistant; Philip G. Koehler, professor, Entomology and Nematology Department, Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville FL 32611.

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other extension publications, contact your county Cooperative Extension service.

U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Millie Ferrer, Interim Dean.