three-lined cockroach (Luridiblatta trivitatta) on Sep 21, 2025
Submitter has sample
Description of specimen
Three lined cockroach
Commentary
Thank you for your report! You are correct, that is 3-lined cockroach, the recent invader, rather than the more common German cockroach. Luckily, the 3-lined cockroach is a nuisance pest that may come indoors at the end of summer, whereas German cockroach is a major public health hazard and very difficult to exterminate. Here is a fact sheet from UC: you may not need to take any control measures at all if numbers are low. https://ucanr.edu/blog/pests-urban-landscape/article/three-lined-cockroach-introduced-nuisance-pest-california
https://ucanr.edu/blog/pests-urban-landscape/article/three-lined-cockroach-introduced-nuisance-pest-california
Tom Valente
Sept. 22, 2025, 3:55 a.m.