The first recorded occurrence of the harvestman, Nelima gothica Lohmander in East Anglia

T H E FIRST RECORDED OCCURRENCE OF THE HARVESTMAN NELIMA GOTHICA LOHMANDER IN EAST ANGLIA PAUL

LEE

Harvestmen are arachnids of the order Opiliones, related to the spiders, and at first sight looking like long-legged versions of their cousins. On closer inspection further differences between the two groups become obvious.

Harvestmen have just two large eyes set on a small protuberance, the occularium, and their rounded bodies appear to be a single unit unlike the 'two-part' body of the spider. This latter difference is due to the cephalothorax and abdomen being joined by a narrow waist, the pedicel, in spiders but being joined across their whole breadth in harvestmen. Harvestmen are active hunters and do not spin webs for catching prey.

There are currently 23 species of harvestman on the British List of which 19 have previously been reported from the county of Suffolk. The species Nelima gothica Lohmander, 1945, which is the subject of this paper, now brings the number of taxa on the County List to twenty. It can be distinguished from all other British species of the order Opiliones by the combination of two characters; the pectination (comb-like structure) on its pedipalpal claw and the lines of short spines above each eye. These characters can be seen with the aid of a 20x handlens making recognition of the species relatively easy.

Pectinated pedipalpal claw and occularium with spines above the eyes of Nelima gothica

Distribution of Nelima gothica in Britain Hillyard and Sankey (1989) describe the species as having a wide distribution but being sparsely recorded, and Sankey (1988) believes it is probably underTrans. Suffolk Nat. Soc. 27 (1991)

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recorded. The records suggest a preference for a moist ecosystem being mostly either north-western or coastal in origin. The most south-easterly record is from beside the main railway line from Bristol in London and Sankey (1988) suggests the species may have been transported there from the south-west either as eggs or as small immature specimens.

The East Anglian record A single female specimen was taken by the author on 23rd September 1990 from a rubble pile beside a bridleway on Oulton Marshes in Camps Heath, Lowestoft (grid ref. 62/510939). The specimen was resting on the underside of a stone atop the pile. A hedge of hawthorn shaded the site and a stagnant ditch was present at the opposite side of the track approximately 2m away.

The rubble appeared to have been present on the site for at least several months as it had been overgrown with nettles and other vegetation. The specimen is now in the author's own collection.

Discussion The new record would appear to fit into the existing pattern of coastal distribution for the species. There does exist the possibility that the specimen was transported to the site with rubble. However, as further rubble of local origin has been observed being transported to the vicinity of the record site, the specimen would still appear to be of local origin also. The habitat from which it was taken also agrees closely with those reported by Sankey (1988) namely rank grassland, hedgebanks and ditchbanks.

The record represents a major extension of the known distribution of Nelima gothica in Britain, the nearest site to Lowestoft being well over 130km away. However, this is most probably a reflection of collecting effort rather than the discovery of a truly isolated population. Sankey (pers. comm.) expects the species to be found at other localities throughout East Anglia.

The author would be extremely pleased to receive other records of harvestmen from Suffolk and will undertake to identify specimens sent to him with full data, i.e. locality, grid reference, date and name of collector.

Further habitat data is especially useful. Live specimens should survive a short journey through the post if packed in a stout container with a small amount of damp tissue. Specimens preserved in alcohol are particularly welcome.

Acknowledgements The author wishes to thank Mr. J. H. P. Sankey, the national recorder for the harvestmen, for confirming the identity of the specimen.

Trans. Suffolk Nat. Soc. 27 (1991)

THE FIRST RECORDED OCCURRENCE OF THE HARVESTMAN NELIMA

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References Hillyard, P. D. & Sankey, J. H. P. (1989). Harvestmen. Synopses of the British Fauna (New Series) No. 4. Leiden. E. J. Brill.

Sankey, J. H. P. (1988). Provisional Atlas of the Harvest-Spiders (Arachnida.Opiliones) of the British Isles. Huntingdon. Biological Records Centre.

P. Lee, Rochdale Cottage, Camps Heath, Lowestoft, NR32 5DW

Trans. Suffolk Nat. Soc. 27 (1991)