Stenopsocus immaculatus (Stephens, 1836)

The identification characters used by New (2005) and Lienhard (1998) to separate S. immaculatus and S. lachlani have been shown to be largely unusable with British specimens (see Saville, 2009). The only character that can be used is the ratio of the distance between the eyes to the longest diameter of an eye (IO/D ratio). The ranges of these ratios for the two species are: S. immaculatus - male (0.8-1.1), female (1.6-2.1); S. lachlani - male (1.3-1.5), female (2.2-2.4).

The National Biodiversity Network records are shown on the map below.

The following datasets are included:

• National Barkfly Recording Scheme - Outdoor Psocoptera (barkfly) records for Britain & Ireland, 1850 to present.
• Merseyside BioBank - Merseyside Environmental Advisory Service Dataset
• Bristol Regional Environmental Records Centre - BRERC October 2009
• Worcestershire Biological Records Centre - Worcestershire Wildlife Trust species data for owned and managed Reserves within Worcestershire from date of first acquisition to present.
• Tullie House Museum - Tullie House Museum. Invertebrate Records other than Lepidoptera. Pre-2009 for Cumbria
• Scottish Wildlife Trust - Commissioned surveys and staff surveys and reports for SWT reserves.
• Worcestershire Biological Records Centre - WBRC Species data for Worcestershire collated by species group
• Sussex Biodiversity Record Centre - Patrick Roper's Notebooks
• Countryside Council for Wales - Welsh Invertebrate Database (WID)
• Natural England - Invertebrate Site Register - England.
• Suffolk Biological Records Centre - Suffolk Biological Records Centre (SBRC) dataset
• Bedfordshire and Luton Biodiversity Recording and Monitoring Centre - Bedfordshire Lacewings and Allies (BNHS) - 1942-2009
• Worcestershire Biological Records Centre - WBRC Species data for Worcestershire collated by date.
• Wiltshire and Swindon Biological Records Centre - Wiltshire & Swindon Site-based Survey Records
• Staffordshire Ecological Record - SER Site-based Surveys

The National Biodiversity Network records are shown on the map below.

The following datasets are included:

• National Trust - Wicken Fen nature reserve species data held by The National Trust
• National Barkfly Recording Scheme - Outdoor Psocoptera (barkfly) records for Britain & Ireland, 1850 to present.

Summary: has been found on a wide range of deciduous and coniferous/evergreen tree and bush branches (no records from trunks).

Associations:

• Deciduous branches: alder, ash, beech, birch, blackthorn, elder, field maple, hawthorn, hazel, honeysuckle, hornbeam, lilac, lime, oak, plum, rowan, Salix lapponum, sallows and sycamore.
• Conifer/evergreen branches: broom, gorse, holly, larch, pine, sitka spruce and yew.
• Other microhabitats: leaf litter and log pile.

Sampling techniques: beating branches, hand searching and litter sieving.