Ero aphana (Araneae: Mimetidae), a spider new to Essex
Red Data Ploughman's Spikenard Inula conyzae adjacent to scrub at the south-western end of the
site.
Before July 2003 the grassland represented an important structural and vegetational mosaic, as
evidenced by the remarkable diversity of invertebrates dependent on different food plants and
forage species. The site is evidently much used by the public to walk dogs and as general amenity
land, and paths cross the grassland and scrub. The grassland on higher ground at the northern end
is much shorter, drier and rabbit grazed. Additional diversity is provided by valuable forage
developed in disused allotment plots. The hedgerow running along the north-eastern edge of the
site contains some White Bryony Bryonia dioica, the forage plant for the RDB3 mining bee Andrena
florea.
Unfortunately between the 19th June and 8th July the whole grassland area was cut from edge to
edge, removing all forage and structural diversity. A further visit on the 20* August found the
grassland apparently having been cut at least once again, with a fairly recent cut. The effect on the
Ero aphana and other rare invertebrate populations is likely to be highly detrimental. Input from
the Thurrock Biodiversity Action Group (TB AG) has now hopefully put in motion a more enlightened
management of the grassland at the site.
Anchor Field represents a. unique green field fragment of the pre-quarry landscape and is home to
many rare and scarce invertebrate species, including what may be the largest national population of
a distinctive Red Data Book fly Dorycera graminum (Harvey 2003), the bumblebee Bombus humilis
and the solitary wasp Cerceris quinquefasciata, all national BAP species on English Nature's Species
Recovery Programme. Unfortunately, despite the known presence of these species, the Local
Authority allocated the site for housing in the next UDP, which was at Deposit Stage last year. The
future for the site looks bleak.
It is one of a number of Thurrock sites for which the Council commissioned survey work to inform
the planning process and the author is grateful for permission to cany out part of this survey and to
publish results.
References
ASKINS, M. & JONES, D. (1998) Ero aphana (Walckenaer, 1802): New British records. News!. Br.
arachnol. Soc. 81: 10-11.
BRATTON J. H. (Ed.) (1991) British Red Data Book 3 Invertebrates other than Insects. JNCC.
DAWSON, I. (2003) Rare heathland records. S.R.S. News No. 45 in News!. Br. arachnol. Soc. 96: 9.
DENTON, J. (2004) Instant results with Ero aphana (Walckenaer). . S.R.S. News No. 48 in News/. Bk
arachnol. Soc. 99: 12.
HARVEY, P & HOPKIN, S. (2003) new records of Ero aphana (Walckenaer, 1802)._SRS News. No 46 In
Newsl. Br. arachnol. Soc. 97: 14.
MERRETT, P. & SNAZELL, R.G. (1975) New and rare spiders. Bull. Brit, arach. Soc. 3 (4): 106-112.
McCARTHY, C. (2002) Ero aphana (Walckenaer, 1802) in a suburban Surrey suburban garden. S.R.S.
News No. 44 in Newsl. Br. arachnol. Soc. 95: 9.
Essex Naturalist (New Series) 21 (2004)
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