Asian Cockroach

Blattella asahinai · Order: Blattodea · Family: Ectobiidae

Nuisance, not dangerous. It can enter homes and become a nuisance.

Source: Wikipedia, urbanentomology.tamu.edu

Asian cockroaches are small, about 1.3-1.6 cm long, and look almost identical to German cockroaches, with tan to brown bodies and wings. They live mainly outdoors in shaded, moist mulched areas, are most active at dusk, and may occasionally wander into houses.

Source: Wikipedia, urbanentomology.tamu.edu

How to recognize it

For practical purposes they look the same as German cockroaches.

Source: urbanentomology.tamu.edu

Size

Adults measure about 1.3 to 1.6 cm (½ to 5⁄8 in) in length.

Source: Wikipedia

Is it a pest in the house?

They are now common around U.S. houses, though indoor invasions are rare. They can enter homes and become established, especially in warmer regions.

Source: Wikipedia, urbanentomology.tamu.edu

Does it bite or sting?

Research has not shown them to carry any pathogens or diseases. They may pick up bacteria from outdoor sources such as animal feces and fungi.

Source: Wikipedia

How to get rid of it

They respond to the same insecticides used for German cockroaches. Several scatter baits have been developed and successfully control their populations. Small morphological differences (mandible, wing veins, cerci bristles) can be used to tell them apart.

Source: urbanentomology.tamu.edu, Wikipedia

Where it lives

They are mostly found outdoors in shaded, mulched or composted sites with fresh plant litter and damp conditions.

Source: Wikipedia

What it eats

In Texas they have become the main predator of bollworm eggs in the Rio Grande Valley. They encounter bacteria from outdoor pathogens, animal feces, and fungi in their habitats.

Source: Wikipedia

Life cycle

Their numbers peak in late August and drop quickly when cooler weather arrives.

Source: Wikipedia

Where it comes from

The species was first described from specimens collected on Okinawa Island, Japan in 1981.

Source: Wikipedia

Lookalikes

They are often mistaken for German cockroaches because of their near-identical appearance.

Source: Wikipedia, urbanentomology.tamu.edu

Where it is found in the US

Recorded in 10 of 51 states and DC. Most records: Texas, Florida, Alabama, Georgia, South Carolina, Louisiana, Mississippi, North Carolina.

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Darker = more records. Counts are museum and citizen-science records, not population size.

Source: GBIF

Status: introduced in North America; introduced in United States. Source: iNaturalist

Months it is reported in the US

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Source: GBIF

More photos

Asian Cockroach photo 3 — Photo: Natasha Wright, Florida Department of Agriculture and Consumer Services, Bugwood.org, CC BY

Asian Cockroach photo 4 — Photo: Natasha Wright, Florida Department of Agriculture and Consumer Services, Bugwood.org, CC BY

Asian Cockroach photo 5 — Photo: Jessica, CC BY

Asian Cockroach photo 6 — Photo: Amber M. King, CC BY

Questions people ask

How can I tell an Asian cockroach from a German cockroach?

Look for subtle differences such as the left mandible surface, wing vein colour, wing size and the bristles on the cerci; otherwise they look the same.

Source: Wikipedia, urbanentomology.tamu.edu

Do Asian cockroaches bite or spread disease?

Research has not suggested that Asian cockroaches carry any diseases, though they do pick up bacteria outdoors around homes, from animal droppings and fungi.

Source: Wikipedia

What should I do if they get into my house?

Use standard cockroach insecticides or scatter baits, which are effective against Asian cockroaches.

Source: urbanentomology.tamu.edu

Are Asian cockroaches a problem for crops?

In Texas they help by eating bollworm eggs, which are pests of cotton and other crops.

Source: Wikipedia