INTRODUCTION
Contrary to its common name, the Oriental cockroach is thought to be of north
African origin. It is also commonly called a "black beetle" or
"waterbug" or "Shad roach." This species has worldwide distribution.
RECOGNITION
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. Male's 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.
SIMILAR GROUPS
(Adults only)
- Smokybrown cockroaches (Periplaneta fuliginosa) with wings
extending to tip of abdomen.
- American cockroach (P. americans), Australian cockroach (P.
australasiae), and brown cockroach (P. brunnea) with wings extending to tip of
abdomen and with pale markings.
- Other cockroaches are either smaller or larger,- have fully developed
wings, are not uniformly black in color, and/or are not associated with structures.
BIOLOGY
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.
HABITS
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 from 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.
