Field Cockroach, Blattella vaga¹

D. R. Suiter and P. G. Koehler²

APPEARANCE

The Field cockroach (Figure 1) is very similar in appearance to the German cockroach . It can be distinguished from the German cockroach by the blackish/brown area on the face from mouth parts to between the eyes. This species is slightly smaller and more greenish-brown in coloration than is the German cockroach.

Figure 1.

German cockroach.

HABITAT

The field cockroach is believed to be an introduced species and was introduced from Asia into southern California, Arizona, New Mexico, and Texas.

The field cockroach, unlike the German cockroach, is not repelled by light and can often be seen during the day. It is most common in irrigated regions of southern Arizona and adjacent areas in southern California. It is associated with and feeds largely on decomposing vegetation; it also occurs under stones, clumps of earth, and similar objects. During the drier part of the year, it temporarily may come into the house in search of moisture.

BIOLOGY AND HABITS

A life cycle can be completed in about 3 months. Female field cockroaches carry their egg capsules until they are ready to hatch. The number of eggs in a capsule usually is between 30-40, with a maximum of 48. The average number of nymphs hatching is 30. The average incubation period is 28.4 days. Capsules removed from the female do not usually hatch. Females at room temperature may produce an average of 4-5 capsules.

The time for nymphs to mature to adults averaged 103 (54-215) days. They progress through 6-7 nymphal instars in 60 days for males and 65 days for the females. Females may live for more than 200 days.

CONTROL

Because the field 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 field cockroach populations around houses. Control can be obtained by removing decomposing plant material from around the home. Spray foundation area, edges of lawn, outdoor flower boxes, and similar areas where moisture collects with a water base spray.

Footnotes

This document is ENY236, 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-Chancy, Interim Dean.