Riparian Woodlouse

Hyloniscus riparius · Order: Isopoda · Family: Trichoniscidae

No source yet on danger. We have no source yet on whether it bites, stings or damages anything.

The riparian woodlouse is a woodlouse species native to Central and Eastern Europe and now also found in North America. It lives on flood-plain habitats and can survive being underwater for as long as eight weeks.

Source: Wikipedia

Where it comes from

Its native range is Central and Eastern Europe, and it has been introduced to North America.

Source: Wikipedia

Where it is found in the US

Recorded in 25 of 51 states and DC. Most records: New York, Vermont, Minnesota, Virginia, Pennsylvania, Connecticut, Wisconsin, Massachusetts.

AKMEVTNHWAIDMTNDMNILWIMINYRIMAORNVWYSDIAINOHPANJCTCAUTCONEMOKYWVVAMDDEAZNMKSARTNNCSCDCOKLAMSALGAHITXFL

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

Source: GBIF

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

Months it is reported in the US

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Source: GBIF

More photos

Riparian Woodlouse photo 2 — Photo: Katja Schulz, CC BY

Riparian Woodlouse photo 3 — Photo: psweet, CC BY-SA

Riparian Woodlouse photo 4 — Photo: Betsy Lambert, CC BY

Riparian Woodlouse photo 5 — Photo: Brett Ortler, CC BY

Same family (Trichoniscidae)

Spurred RidgebackHaplophthalmus danicus

Sources

Wikipedia: https://en.wikipedia.org/wiki/Hyloniscus_riparius

Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia

Text written 2026-10-25 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-25.