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Oriental Cockroach, Blatta orientalis1
D. R. Suiter and P. G. Koehler2APPEARANCE
The oriental cockroach is dark-brown to black in color. The adult is 1 inch in length. The male has fully-developed wings, but does not fly. The female has rudimentary wings which are reduced to mere lobes. The mature female may be distinguished from the large nymph by the fact the wing stubs have a definite venation. The abdomen of the female is broader than the male and appears to be dragged along the floor when the insect is in motion, while the male keeps its body clear of the ground when running. The male can be recognized by the styli between its pairs of jointed cerci.HABITAT
The oriental cockroach is most common in dark, damp basements, but is known to climb water pipes to the upper floors of apartment houses. Since high-rise apartments cannot burn garbage, oriental cockroaches have a free highway to climb to upper floors via garbage chutes.BIOLOGY AND HABITS
The female may carry the brown egg capsule for 30 hours. A full complement of 16 eggs can be laid in the egg capsule. The average number of nymphs to hatch per egg capsule is 14.4. The female may deposit 1-18 egg capsules with an average of eight per female. The egg capsule is carried from 12 hours to 5 days and then deposited in some warm sheltered spot where food is readily available. In this species the female cockroach gives no assistance to her newly born young. At room temperature, the incubation period was 42 to 81 days, with an average of 60 days.The developmental period for the oriental cockroach is 12 months, during which interval the insect undergoes 7 molts. The adults appear in May, June, and July, and the nymphs are more and more evident during summer months. The time it took the oriental cockroach to complete development in the laboratory varied from 311 to 800 days. Capsules were produced from December to August. No adults matured during the months of October, November, and December. The adult females may live from 34 to 181 days.
The oriental cockroach is less wary and more sluggish than other cockroaches. It often travels through sewer pipes and lives on filth. It may enter the home in food packages and laundry, or merely come in under the door or through air-ducts or ventilators. This cockroach prefers to feed upon starchy foods.
CONTROL
Oriental cockroaches tend to remain near their preferred harborage site, and barrier treatments of encapsulated insecticide in June (in Virginia) provided control through the summer activity period.At times large numbers of oriental cockroaches occur in one great mass around leaks in the basement or crawl space areas of homes. By increasing ventilation (e.g. trimming shrubbery and permitting the sunlight to enter through the ventilators), it is possible to decrease the dampness beneath homes, and thereby greatly reduce infestations.
Footnotes
1. This document is ENY239, 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 Octobe 1991. Reviewed May 2003. Visit the EDIS Web Site at http://edis.ifas.ufl.edu.2. 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.
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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. Larry Arrington, Dean.
Copyright Information
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