Oriental Cockroaches

Oriental Cockroach Appearance

Oriental Roaches are commonly called water bugs or black beetles.

This cockroach is shiny black and is about 1.25 inches long. They have wings, but the male or female roach can not fly. The total length for the female is 1 ¼" and 1" for the male. The females have small nonfunctional wings while the males have wings that cover about ¾ of the abdomen, nether the female or male can fly. Adults are very dark brown or black in color.

Oriental Roach Diet

The Oriental roach like decayed organic matter in mulch piles and rubbish. The Oriental cockroach prefers starchy food, and builds up populations around garbage cans.
Most of their water consumption is gotten through their food and the moisture around them.

Habits and Biology of Oriental Cockroaches

Females produce an average of 8 egg Capsules, containing 16 eggs in each,from spring to mid-summer. Unlike other urban cockroaches, the Oriental roach produces only one generation per year where temperatures are cool in winter.

The female will carry the egg capsule(irregularly shaped,black,3/8" long,and 1/4"wide), for around 30 hours and then drops or attaches it in a protected area, near a food supply. The eggs hatch in about 60 days under warm conditions. At least 75% of the eggs must hatch to open the capsule.

The young become adults in 6-12 months. Nymphs(young) are active from about March through much of the summer. During this period they molt seven to ten times, and are reddish-brown to black in color, except in the first stage when they are pale tan. The older brown Oriental cockroach nymphs are very difficult to distinguish from the American cockroach nymphs.

This type of roach will have seasonal cycle in it's development. They peak to adults during the spring and early summer, dwindling in numbers by the late summer/early fall. Nymphs(young) are active from about March through much of the summer. During this period they molt seven to ten times, and are reddish-brown to black in color, except in the first stage when they are pale tan. The older brown Oriental cockroach nymphs are very difficult to distinguish from the American cockroach nymphs.

In early spring, only adult Oriental cockroaches are found. By late spring, nymphs are abundant. As nymphal numbers increase, the adults die off and by August any adults are new ones. By fall, almost the entire population is adult.

Inside they can be found in damp areas such as basements, crawl spaces,and kitchens, indoors and outside.

They are usually found at or below ground level in yards, beneath leaves, in dumps, in the mulch of flower beds and in high moisture situations such as sewers, drains and dark, damp basements. They favor crawl spaces, spaces between the soil and building foundations, the undersides of stoops and sidewalks, landscaping mulches, water meters, basements and their floor drains, and other such moist places.

These cockroaches frequently live in floor drains that drain directly outside; these drains are also used as entrances to homes.
They tolerate lower temperature ranges than other roaches and may winter in rock walls or such protected sites.

During times of drought there may be movement towards the inside of the home, but generally speaking they are found outdoors during the warmer months. They may also move inside if it is unseasonably cold.

Recommendations for Oriental Roach Control

  • Caulk all penetrations through ground level walls.
  • Stop water leaks, screen equipment overflow drains, and take overflow water away from buildings; keep drain traps full or capped.
  • Remove rotting leaves from window wells.
  • Move garbage cans out of preferred moist habitat.
  • Ventilate moist spaces.

Generally speaking, control measures should concentrate on the outside of the building and points of entry. This is called a "perimeter or barrier" treatment.

Recommended residual sprays for perimeter treatments, basements and attics

Lambdastar Ultracap 9.7

lambdstar ultracap

LambdaStar Ultracap 9.7 (Broader label and longer lasting-may be used inside or outside and will dry invisible. Lambdastar Ultracap has no smell. LambdaStar Ultracap will last longer outside and adhere to the surface better due to its encapuslated technology.

Cyper WSP and Demon WP

cyper wsp

Cyper WSP
Cyper WSP and Demon WP have the same label, but Cyper WSP is more economical.


Demon WP

Demon WP and Cyper WSP will leave a visible residue seen against dark wood.

D-Fense SC

d-fense sc

D-Fense SC will also dry invisibly with no smell. It can be used inside or outside. The pint will yield 11-22 gallons.

Where to spray:
You may use three residual sprays : LambdaStar Ultra Cap 9.7, Cyper WSP or Demon WP inside or outside.

Spray outside around doors, windows, pipe openings, and dryer vents. Apply also on the inside on the baseboards near the entry pts.

On the inside-apply around the plumbing under the sinks and washer and dryer connections. You don't have to spray all the interior baseboards, just the corners and baseboards inside the garage and basement areas.

For additional treatment: You may apply Bifen LP Granules around the base of the house, particularly in areas of pine straw and mulched areas and or Intice Perimeter Bait as supplemental treatments. If you have these larger cockroaches entering inside your home from the attic area (due to trees that overhang the attic or gutters that are not clean) using baits like Intice insect baits, would give you very good results.

Bifen LP

Bifen Granulars

intice perimeter bait

Intice Perimeter Bait

Intice Perimeter Bait not only works well around the perimeter, but would also be excellent choices for crawl spaces and or attics.

The residual insecticides : LambdaStar UltraCap 9.7, Cyper WSP, and Demon WP as well as the residual granulars: Bifen LP Granules should be repeated every three months during the season.

The Intice baits last from 6 months to a year, free from rain. Feel free to call if you have any questions.

* photograph of the Oriental cockroach is courtesy of: University of Lincoln-Nebraska Dept. of Entomology