Oriental Cockroaches

Oriental Cockroach Scientific Name: Blatta orientalis

Oriental Cockroach Facts

This species of cockroach is a seasonal insect that is most easily spotted during spring and summer. It is also called “black beetle,” “waterbug,” or “shad roach” because its progeny come out in large numbers when shad fish are swimming into fresh waters for breeding.

This pest is different from other pest cockroaches in that it doesn’t have sticky pads on its feet and can’t climb slippery or smooth surfaces. Oriental cockroaches can live for a month without food if there is water around. Some males are able to take short flights, around 2 to 3 meters.

Oriental Cockroach Identification

This major household pest is found in the mid-west, northwest, and southern United States. An adult Oriental cockroach is about an inch long (2.5 centimeters). Its glossy body is dark brown or black. The female has a wide body and looks wingless, but actually has two small, flightless wings (tegmina) below her head. Females look like the Florida woods cockroach species and are often mistaken for it. The male Oriental cockroach has long brown wings (tegmina) that cover most of its narrow body. A male Oriental cockroach’s head is almost hidden underneath a large hard collar (pronotum) at the front of the thorax. The cerci at the back of the abdomen are used as sensory organs.

Oriental Cockroach Habitat

This cockroach is a slow traveler. People refer to them as waterbugs because they live dark, wet environments. They congregate around damp basements, decaying organic material, drains, porches, under sinks, crawl spaces, and sewers. In the outdoors, they like damp areas like bushes, under leaf groundcover, cisterns, water valve pits, foundations, dumps, garbage cans, trash chutes, and under mulch.

These pests need food and water and warm, humid places to hide between 68 degrees Fahrenheit (20 degrees Celsius) and 84 degrees Fahrenheit (29 degrees Celsius). Oriental cockroaches mostly come out at night and are good at hiding during a casual inspection of a suspected infested home during the day. Adults and nymphs are slow and often living at or under ground level indoors. They aren’t often on walls, high cupboards, or on upper floors of buildings. Sometimes a population of Oriental cockroaches will hang out near leaks in a basement or crawl space. In warm weather, Oriental cockroaches like the outdoors, but move indoors during droughts seeking higher humidity. These pesky roaches come into homes under doors, through air ducts, garbage chutes, or ventilators or on food packages and laundry.

These pests like to feed on decaying organic material, filth, garbage, and the leftovers in old tin cans. They do the most damage from eating and living in moist, dirty areas such as bathrooms, garbage disposals, indoor storage areas, kitchens, and sewers. Oriental cockroaches spread disease to dishes, food preparation surfaces, food supplies, and other surfaces. They spoil more food than they eat.

Oriental Cockroach Life Cycle

Female Oriental cockroaches lay eggs in capsules and carry them for 30 hours. They drop 5 to 10 oothecae (egg cases) with up to 16 eggs in them without gluing them to any surface. The eggs hatch unattended by the mother in around 2 months. Cockroach nymphs hatch from egg cases in 6 to 8 weeks. An Oriental cockroach male lives for about one and a half years with nymphal development at 6 to 12 months. Females live for 5 to 26 weeks and have 200 babies.

This cockroach develops seasonally with the largest number of full-frown Oriental cockroaches appearing in late spring or early summer. Their numbers dwindle by late summer or early fall because of nymphs hatching and natural mortality.

Oriental Cockroaches and Humans

These pesky invaders enter homes through air ducts, sewer pipes, or any other opening. They produce malodorous secretions from all over their bodies. The nasty secretions affect the flavors of food. When there are lots of cockroaches in an area, their odorous secretions can cause a huge stink in the infested area. All kinds of disease-producing things like bacteria, protozoa, and viruses are all found on cockroaches’ bodies. Oriental cockroach fecal matter and skin casts contain lots of allergens that cause asthma, congestion, skin rashes, sneezing, and watery eyes. They also cause different forms of gastroenteritis like diarrhea, dysentery, and food poisoning.

Oriental Cockroach Control

  1. Oriental Cockroach Identification: A professional exterminator will look for Oriental cockroach egg cases that females have dropped. This is a sure sign that Oriental cockroaches have invaded the home.
  2. Bait and Insecticide: A professional pest control expert can use baits with abamectin, boric acid, hydramethylnon, and sulfluramid. They can spray a perimeter insecticide to make a continuous barrier around the house. Boric acid, diatomaceous earth, and silica aerogel dusts can be sprinkled into cracks, crevices, and voids which will stick to the oily surface of the roach’s body and dehydrate or poison them to death.
  3. Removal of Oriental Cockroaches: These pests can be harder to exterminate than other species of roach. The adults can be killed easily with residual insecticide, but the insecticides need to be reapplied because females will hatch more nymphs. Vacuuming and sanitizing the area after multiple applications of insecticide is recommended.

DIY and Green Solutions for Oriental Cockroach Control

  1. Clean it up! Sanitation is the first step towards treating an Oriental cockroach problem. Remove food particles and dirty messes, cockroaches love filth.
  2. Dust them! Boric acid, diatomaceous earth, and silica aerosel dusts can be spread in lightly in cracks, crevices, and wall voids. If dusts are too heavily applied Oriental cockroaches will avoid them. Dusts should not be applied to damp or wet areas. Make sure dusts are not sprinkled in places where kids and pets can come into contact with them and make sure dusts aren’t applied where they can contaminate food.
  3. Fix it up! Getting rid of cockroach harborages requires caulking inside cabinets, closets, under the sinks, in the kitchen, bathrooms and other places in the home with cracks and crevices.
  4. Trap them! Place sticky traps in strategic locations in the home, if possible, against walls or in corners to trap Oriental cockroaches. You can tell after a week how big your pest problem is and where the invasion is at its worst.