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The modern distribution of harvestmen (Arachnida: Opiliones)
in Essex with their regional rarity and threat status
PETER R. HARVEY
32 Lodge Lane, Grays, Essex RM16 2YP
Abstract
Modern recording of harvestmen in Essex species accounts for each species.
has resulted in reasonable coverage of the Regional status categories based on
county. The data have been used to Harvey (1998) are defined and used to
provide distribution maps and detailed provide the county rarity and threat
Introduction
Regional data on the distribution and status of invertebrates has increasingly been addressed in
Britain with the publication of County Red Data Books which include invertebrates e.g. the
Dorset Red Data Book (Mahon & Pearman 1993). those for specific invertebrate groups such as
aculeate Hymenoptera in Yorkshire (Archer 1998) and county faunas on the more 'popular'
invertebrate groups such as butterflies and dragonflies, and Hoverflies (Morris 1998; Levy &
Lew 1998) and other groups.
The Recorders of the Essex Field Club have produced a provisional Essex Red Data list for the
comity's flora and fauna which can aid and complement the implementation of the Essex
Biodiversity Action Plan and inform the selection of County Wildlife Sites. A detailed analysis
of the comity status of ants has been covered by the author's paper in the 1998 Essex Naturalist
(Harvey 1998). Coverage of harvestmen in the county is reasonably good and as a continuation
of this process for invertebrates detailed information on the county status of harvestmen species
is given in this paper.
Our knowledge of harvestmen in Essex
Coverage of the county at the time of Sankey (1988) was not good and even common species
arc not represented in the south and west of the county. The present distribution maps arc the
cumulation of nearly 2500 records made since 1969 with most records in the period from 1986
to 1999. The bulk of modern records have been made by the Essex Spider Group (R. Ruffell.
D. Carr. K. Hill and the author) in the course of their extensive fieldwork over much of Essex
for spiders. As well as records resulting from sweeping, direct observation, 'grubbing around'
and sieving leaf litter oilier records have resulted from pitfall trapping. Many older records for
the Colchester and St. Osyth area were made between 1969 and 1977 by P. V. Hicks and these
records were provided by the Colchester Natural History Museum. Valuable records have also
been provided by Southend Museum (R. G. Payne) and material which lias included harvestmen
has been provided by various field workers particularly Paul Mabbott from the Epping Forest
area and C.W. Plant. Other records were made by the Passmore Edwards Survey Team in the
period 1984-5.
A total of twentyone species has now been recorded for the county including Nelima gothica.
Essex Naturalist (New Series) 16 (1999)