How to Get Rid of Oriental Roaches

Here’s what to do when you spy one of these disgusting pests in your house.

Entomologists call it Blatta orientalis. Polite company may call it a water bug or black beetle. However you refer to it, the Oriental cockroach may just be the foulest of all roach species. Like other roaches, they are carriers of bacteria, viruses, and other microorganisms. While they don't cause direct harm to humans, they do spread disease-causing microorganisms, excrement, and castoff skin wherever they go. If exposed, people who are sensitive (especially those with asthma) may experience an increase in symptoms like wheezing, sneezing, itching, and watery eyes. Oriental cockroaches in particular also have an especially foul "roachy" odor.

What Oriental Cockroaches Look Like

The Oriental cockroach is neither a water bug nor a black beetle, though it does love moist areas and is very dark in color. Adult males are about an inch long; adult females are slightly longer, at an inch and a quarter. Both are black with bodies that have a greasy-looking sheen.

Though Oriental cockroaches cannot fly, they do have wings. Female wings are short and triangular. Male wings are more developed and run nearly the length of the roach's body. Nymphs (baby roaches) are wingless.

The lifespan of an adult female is anywhere from a few weeks to a few months. During this time, she'll produce about 150 nymphs, which take 12 months or more to fully develop. Adult populations of the Oriental cockroach peak in early summer, so infestations tend to happen from spring to fall.

Quickly identify an oriental cockroach

  • Shiny black appearance
  • Oval-shaped body
  • 6 spiny legs
  • 2 long antennae
  • Adults grow to about 1-1.25 inches long
  • Males are flightless but have small wings that extend about ¾ of the length of their body
  • Females have even smaller functionless wings
  • Nymphs are wingless

Where Oriental Cockroaches Like to Hide

It's nearly impossible for Oriental cockroaches to climb up smooth, vertical surfaces, so if you see a large roach crawling high up on a wall or cupboard, it's probably not an Oriental cockroach.

Indoors, Oriental cockroaches congregate in large numbers in cool, dark, and moist places. Look for them in areas with ample water.

  • Damp basements
  • Crawl spaces
  • Floor drains
  • Under sinks
  • Around washing machines

Outside, they also prefer damp places. Inspect these areas around your home and landscape. 

  • Cisterns
  • Leaf piles
  • Ground covers
  • Garbage cans and dumping grounds

When there's no water to be found, Oriental cockroaches will try to make their way inside via an opening low to the ground, such as under a door or through an air duct, dryer vent, or garbage chute. Oriental cockroaches feed on filth and garbage, and while they can do without food for a month, they cannot survive more than a couple of weeks without water.

How to Kill Oriental Cockroaches and Prevent Them from Coming Back

1. Give Them What They Want – and More

For every one cockroach you see, there are dozens (even hundreds) more you don't. An effective way to get rid of Oriental cockroaches is to put out Ortho® Home Defense Roach Bait every 6 feet wherever they're found. Each bait station contains a carefully formulated blend of two things they love—food and water—plus an insecticide. Oriental cockroaches find the bait, feed on it, and crawl away to share it with other roaches. Each bait station will stay attractive to these pests for up to 6 months.

2. Spray, Don't Squish

To kill Oriental cockroaches when you see them, spray them with easy-to-use, no-mess Ortho® Home Defense® Ant & Roach & Spider Killer2. It kills on contact when sprayed directly on the bug. It also sanitizes hard, non-food surfaces to protect against listed germs they may leave behind. Don't use spray at the same time you use bait, though, since dead roaches can't bring the bait back to their colonies to share.

3. Keep Future Roaches Out

To keep other Oriental cockroaches from entering your home, create a bug barrier by applying Ortho® Home Defense Max® Indoor Insect Killer with Extended Reach Comfort Wand® along baseboards, around doors and windows, etc. If a roach tries to cross the barrier, it dies. This fast-drying, no-stain, fume-free product protects your home for up to 12 months (indoors on non-porous surfaces) so you don't have to remember to spray every day, week, or month.

More Ways to Prevent Oriental Cockroaches

Limiting their access to the interior of your home, as well as to food and water, can go a long way toward keeping Oriental cockroaches out of your house.

Try these tips:

  • Store food and garbage in containers with tight-fitting lids.
  • Clean regularly with a HEPA-filter vacuum.
  • Fix leaky sinks, pipes, drains, and other plumbing issues.
  • Cap drain traps.
  • Seal off entry points with caulk, screening, door sweeps, or weather stripping.
  • Clear away wet leaves, damp mulch, and water-soaked debris from your foundation.
  • Create a secondary bug barrier outside with an application of Ortho® Home Defense Insect Killer for Indoor and Perimeter2 with Comfort Wand®.

It's natural to want to steer clear of filthy Oriental cockroaches, but it's never a good idea to ignore them. Don't subject your home and family to nasty allergens and contamination when you can use these tips to tackle the problem.

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