Common Name: Oriental Cockroach
Scientific Name: Blatta orientallis Linnaeus
Contrary to its common name, the oriental cockroach is thought to be or north African origin. It is also commonly called a “black beetle” or “waterbug” or “shed roach”. This species has worldwide distribution.
Adult males about 1″ (25 mm) long whereas, females about 1 1/4″ (32 mm) long. Color usually shiny black but may vary to dark reddish brown. Males wings cover about 75% of abdomen, leaving 3 to 5 abdominal segments exposed. Female with much reduced wings which resemble nymphal wing pads but have veins. Adults do not fly. Nymphal early instars shiny reddish brown, cerci rounded laterally and broadly tapering to tip, widest near center. Later instars dark reddish brown to black, cerci rounded laterally and broadly tapering to tip, widest near center with middle segments about 3 times as wide as long and length about 3 times greatest width. Ootheca or egg capsule reddish brown when deposited, then changing to black; about 3/8″ (8-10 mm) long, with length about 1.5 times width; subdivisional furrows extending from less than midwidth to beyond midwidth but are not entire; prominent terminal point; and usually with 8 eggs on each side.
(Adult only). (1) Smokybrown cockroaches (Periplaneta fuliginosa) with wings extending to tip of abdomen. (2) American cockroach (P. americana), Australian cockroach (P. australasiae), and brown cockroach (P. brunnea) with wings extending to tip of abdomen and with pale markings. (3) Other cockroaches are either smaller or larger, have fully developed wings, are not uniformly black in color, and/or are not associated with structures.
The female usually deposits her ootheca within about 30 hours (range 12-120) after it is formed. It is either dropped or glued to something in a warm protected area near a food source. On the average, the female will produce about 8 (range 1-18) oothecae with each containing about 16 eggs. Developmental time (egg to adult) is influenced by temperature, varying from 206-800 days but it takes about 575 (males) and 602 (females) days at ordinary room conditions. Adult females live 34-181 days whereas, males live 112-160 days.
In many areas, the oriental cockroach survives quite well outdoors and spends considerable time there. It is typically found under debris, stones, and leaf litter, but also in wall and porch voids. It has been observed to survive outdoors during 13 weeks of almost continuous freezing weather. They usually enter buildings via door thresholds, under sliding glass doors, along utility pipes and air ducts, through unscreened ventilators, and room floor drains.
Indoors they are typically found in crawl spaces, cellars, basements, and on the first floor but at times on higher floors, especially around water pipes which they typically climb. They feed on all kinds of food and decaying organic matter, but prefer to feed on starchy foods. They are much despised because of their strong “roachy” odor and because they feed on filth.
Follow the standard control procedures but pay particular attention to damp crawl spaces, basements, and floor drains. Outside perimeter/barrier treatments are quite effective, especially when microencapsulated or wettable powder formulations are used.