Stenopsocus immaculatus

A common barkfly. This species has been confused with Stenopsocus lachlani in the past, as most of the criteria used to separate the two species are not reliable. However, Saville (2009)* found that those barkflies identified as lachlani in the UK were in fact immaculatus, concluding that only immaculatus (not lachlani) is present in Britain and that all British records of lachlani should be regarded as immaculatus.

Separation of immaculatus from Stenopsocus stigmaticus is more straightforward as most individuals of the latter species have a thick dark line bordering the rear of the pterostigma. Those that don't have a broader pterostigma and no setae on forewing vein Cu2.

* Saville, R E (2009). The Identity of Stenopsocus species (Psocoptera: Stenopsocidae) in Britain. British Journal of Entomology and Natural History 22(1): 7-13.

2x Stenopsocus immaculatus showing forewings, Ling Plantation, North Elmham (Norfolk, UK), 4th June 2026

Stenopsocus immaculatus showing forewing, Wendling Beck Project (Norfolk, UK), 31st July 2024

Stenopsocus immaculatus showing forewing, Wendling Beck Project (Norfolk, UK), 23rd July 2024

2x Stenopsocus immaculatus showing one's forewing above that of a Stenopsocus stigmaticus, Wendling Beck Project (Norfolk, UK), 12th September 2024

Stenopsocus immaculatus showing forewing, Beetley Meadows (Norfolk, UK), 30th May 2025

third Stenopsocus immaculatus showing forewing and close-up of vein Cu2, Wendling Beck Project (Norfolk, UK), 12th September 2024

Stenopsocus immaculatus showing forewings, Wendling Beck Project (Norfolk, UK), 26th May 2026

Stenopsocus immaculatus showing forewing, Wendling Beck Project (Norfolk, UK), 26th May 2026

Stenopsocus immaculatus showing forewing, Wendling Beck Project (Norfolk, UK), 26th May 2026

Stenopsocus immaculatus showing forewings, North Elmham (Norfolk, UK), 17th June 2022

Stenopsocus immaculatus, North Elmham (Norfolk, UK), 7th September 2024

Stenopsocus immaculatus, North Elmham (Norfolk, UK), 9th Octboer 2024

Stenopsocus immaculatus showing forewing and close-up of vein Cu2, Rush Meadows (Norfolk, UK), 24th July 2024

This individual had very unusual wing venation with a lot of extra veins (and/or ramelli?) giving it the appearance of shattered glass. Though not precisely the same, the pattern was similar on both forewings.

Stenopsocus immaculatus showing forewings, North Elmham (Norfolk, UK), 13th August 2024

Stenopsocus immaculatus showing forewings, North Elmham (Norfolk, UK), 3rd August 2024

Stenopsocus immaculatus showing forewings, North Elmham (Norfolk, UK), 3rd October 2025