Parcoblatta americana
In 3 days ~10% in a week ~30%
Parcoblatta americana, the western wood cockroach, is a species of wood cockroach that occurs in Mexico and the western United States. The species has significant size and color variation, thought to be due to environmental conditions, particularly the effect of aridity.
The male of the species has normal, fully developed tegmina and wings, and a tuft of hairs on the back of its middle abdomen. The general coloration in the male can vary from shining dark brown or blackish to a pale yellowish to slightly reddish tan. The tegmina are translucent in all colorations, and the ocelli (simple eye spots) are a yellowish tan.
Females of the species have very greatly reduced tegmina, represented by lobe-like lateral pads, and no hind wings. The female general coloration ranges from a shining reddish orange or brown, slightly darker on the back of the abdomen, to a shining dark brown, or shining black with blackish brown underparts. The ocelli are tannish in all colorations.
Morgan Hebard's 1917 description included measurement ranges based on 14 male specimens and 7 female specimens: The male P. americana has a single specialized area on... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Sequoia and Kings Canyon National Parks | 🇺🇸 United States | |
| 2 | Yosemite National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | San Diego | 🇺🇸 United States | |
| 2 | Los Angeles | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a Western Wood Cockroach sighting in Yosemite National Park on a given day, based on 6 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 192nd most-seen of the 227 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.
January
In that month about 20% of wildlife watchers report a Western Wood Cockroach in Yosemite National Park on a given day, against under 5% in February, April and June–December, the lowest months. That is one of Yosemite National Park's wettest months, with about 220 mm of rain against 25 mm in September.
Between 8 and 11 pm
Across all the parks we cover, that three-hour window holds the most Western Wood Cockroach sightings with a recorded time, and about 8 in 10 of them come between 6 pm and 6 am: it is mostly seen at night.
2nd of 2
Of the 2 parks where we can rate Western Wood Cockroach sightings, Yosemite National Park ranks 2nd at under 5%. The best odds are in Sequoia and Kings Canyon National Parks (United States, about 10%).
GBIF citizen-science records
It is estimated from how often the Western Wood Cockroach is recorded against all the insects logged in Yosemite National Park (6 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
