Bug FAQJapanese Cockroach
Crescispina japonica · Order: Blattodea · Family: Blattidae
Adults are 25 to 35 mm long, shiny black to black-brown with brown legs and palps. It is native to Japan but has spread to nearby East Asian countries and was first recorded in the United States in New York City in 2013.
Source: Wikipedia
How to recognize it
Males have wings that reach just past the abdomen, while females have wings about half the body length. First-instar nymphs are dark brown with pale tips on their maxillary and labial palps.
Source: Wikipedia
Size
Adults measure 25 to 35 mm (2½ to 3½ cm) in length.
Source: Wikipedia
Is it a pest in the house?
Although primarily outdoor, it can adapt to indoor settings where food is stored or served. Its first U.S. record was in New York City in 2013.
Source: Wikipedia
How to get rid of it
Genetic testing suggests it may have arrived in the park via soil in ornamental plants, highlighting the role of DNA barcoding in urban pest identification.
Source: Wikipedia
Where it lives
It mainly lives outdoors but can also survive inside homes where food is stored or prepared. Nymphs have been seen hibernating in snow-covered areas during sub-freezing winters.
Source: Wikipedia
Life cycle
It can have a one-year or two-year life cycle, with some nymphs spending two winters in diapause before maturing.
Source: Wikipedia
When you see it
Nymphs have been observed hibernating through winter in snow-covered habitats. Individuals were found surviving a cold winter in Manhattan’s High Line park.
Source: Wikipedia
Where it comes from
The Japanese cockroach originates from Japan. It has expanded its range to China, Korea, far-eastern Russia, and central-northern Japan.
Source: Wikipedia
Status: introduced in United States. Source: iNaturalist
More photos
Questions people ask
Where does the Japanese cockroach come from?
It is native to Japan and has spread to China, Korea, far-eastern Russia, and central-northern Japan.
Source: Wikipedia
Can it live inside my house?
Yes, it can adapt to indoor environments where food is stored or prepared.
Source: Wikipedia
How long does it take to develop?
It may complete its life cycle in one or two years, with some nymphs spending two winters in diapause before becoming adults.
Source: Wikipedia
Same family (Blattidae)
American CockroachPeriplaneta americanaCan spread germs or disease
Oriental CockroachBlatta orientalisCan spread germs or disease
Smokybrown CockroachPeriplaneta fuliginosaNuisance, not dangerous
Australian CockroachPeriplaneta australasiaeNuisance, not dangerous
Turkestan CockroachBlatta lateralisNuisance, not dangerous
Brown CockroachPeriplaneta brunneaNuisance, not dangerousSources
- Wikipedia: https://en.wikipedia.org/wiki/Japanese_cockroach
Look it up elsewhere: GBIF · iNaturalist · BugGuide · Wikipedia
Text written 2026-10-24 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-24.