SUMMARY

A survey was undertaken on 28th March 2025 (Forest of Bowland), and 11th and 12th October 2025 (Dales and Bowland) to speculatively search for the Nationally Rare and Endangered Linyphiidae spiders Semljicola caliginosus (Falconer, 1910) and Erigone welchi Jackson, 1911 in Lancashire. Nine sites were identified from aerial imagery and surveyed using vacuum samplers: Clougha, Brownley Hill, Plover Moss, Rigg Lane, Goodber Fell, and Loftshaw Moss (Red Mire) on Bowland, and Gragareth, Green Hill and Great Coum on the Dales.

Erigone welchi was not found. Semljicola caliginosus was recorded at six locations: three sites on Bowland and three in the Dales. These records represent the first for the Forest of Bowland and a new vice-county record for West Lancashire (VC 60). In total fifty specimens of S. caliginosus were found during the study and it was recorded from four hectads, three of which are new hectad records for the species (SD55, SD67, SD68). Climatic threats to S. caliginosus are discussed. Microhabitat loss by localised draining of upland seepages and pools was highlighted as an issue, particularly to small, isolated populations.

In total 54 spider, 2 harvestmen and 1 Pseudoscorpion species were recorded during this survey. Of the 54 spider species, 1 is Nationally Rare and 11 Nationally Scarce. The Nationally Scarce upland Linyphiidae spider Mecynargus morulus (O. P. -Cambridge, 1873) is recorded new to West Lancashire (VC 60).

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Published January 2026