Invasion

Invasion Description

:1st Record: Bay Farm Island/Alameda County/San Francisco Bay (1/28/1935, USNM, 134494, under rocks, above high tide line, with Actoniscus, as Porcellio littorinus)

Geographic Extent

Bay Farm Island/Alameda County/San Francisco Bay (1/28/1935, USNM, 134494, under rocks, above high tide line, with Actoniscus, , as Porcellio littorinus, 12 specimens); 1980, Schultz et al. 1982, 260 specimens); San Mateo/CA/San Francisco Bay (5/23/2019, i-Naturalist 2019); 22 of 160 sites around the Bay/CA/San Francisco Bay (Garthwaite et al. 1992).