Bug FAQWoodland barklouse
Mesopsocus immunis · Order: Psocodea · Family: Mesopsocidae
Also called: Bark louse
Females are about 4 mm to 4.5 mm long and males range from 4.5 mm to 5.5 mm. Females have very small wings while males have long wings, and they live across Western Europe (except Denmark and Iceland) and Hungary.
Source: Wikipedia
How to recognize it
Females possess tiny (micropterous) wings and males have long (macropterous) wings.
Source: Wikipedia
Size
Females measure 4 mm to 4.5 mm; males measure 4.5 mm to 5.5 mm.
Source: Wikipedia
Where it lives
It is found throughout Western Europe, but not in Denmark or Iceland, and also occurs in Hungary.
Source: Wikipedia
Where it comes from
Its range includes Western Europe (excluding Denmark and Iceland) and Hungary.
Source: Wikipedia
Where it is found in the US
Recorded in 5 of 51 states and DC. Most records: California, Washington, Massachusetts, New York, Oregon.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
Where is the woodland barklouse found?
It occurs across Western Europe (except Denmark and Iceland) and in Hungary.
Source: Wikipedia
Same family (Mesopsocidae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Mesopsocus_immunis
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-23.