Bug FAQMesopsocus unipunctatus
Mesopsocus unipunctatus · Order: Psocodea · Family: Mesopsocidae
Adults are tiny, measuring about 2.5 to 3.7 mm long. They show one or two light transverse stripes on a mottled grey-brown abdomen. These barklice live on many deciduous and coniferous trees across the Holarctic, including much of North America.
Source: Wikipedia
How to recognize it
One or two noticeable light stripes run across the abdomen, while the rest of the body is irregularly mottled with darker spots.
Source: Wikipedia
Size
The body length ranges from about 2.5 mm to 3.7 mm.
Source: Wikipedia
Where it lives
It feeds on a wide variety of trees, both deciduous (ash, oak, birch, etc.) and coniferous (cedar, pine, yew, etc.).
Source: Wikipedia
What it eats
It is a generalist that lives on branches of both deciduous and coniferous trees, as well as in hedgerows and shaded meadows.
Source: Wikipedia
Where it comes from
Mesopsocus unipunctatus occurs across the Holarctic region. In North America it is found throughout Canada and the United States.
Source: Wikipedia
Where it is found in the US
Recorded in 16 of 51 states and DC. Most records: California, Alaska, New York, Vermont, Washington, Montana, New Jersey, North Carolina.
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
What does this barklouse look like?
It has one or two light transverse stripes on the abdomen and a mottled grey-brown body.
Source: Wikipedia
Where can I find Mesopsocus unipunctatus?
It lives on many trees across the Holarctic, including throughout Canada and the United States.
Source: Wikipedia
Same family (Mesopsocidae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Mesopsocus_unipunctatus
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.