6
ANTS IN ESSEX
Like many other invertebrates ants are an overlooked and very under-recorded group, not
only in Essex but in the country as a whole. Yet everybody is familiar with the common
black ant Lasius niger and the mound building Meadow ant L. flavus. Although the
Meadow ant is widespread and common, even in many gardens, the old grasslands and
meadows with their large numbers of ant hills are sadly a rare sight today.
Ants form a small group of about 47 native species in this country. Despite this there can
be difficulties in the identification of some groups of close species. This is especially so if
only one or two individual worker ants are available. The lack of good or easily
obtainable identification guides or keys has made life difficult in the past.There is one
book that 1 would recommend to anyone seriously interested in the identification of
British ants, "The Formicidae (Hymenoptera) of Fennoscandia and Denmark" by CA.
Collingwood, in the Fauna Entomologica Scandinavica series (Volume 8, 1979). It is
written in english, easily obtained from specialist natural history booksellers and contains
all the British species. The keys are clear and it is well illustrated with diagrams that help
clarify identification within difficult genera such as Myrmica and some of the species
groups in Lasius.
There are some changes afoot and new species now recognised. For example, it has
recently been discovered that we have two species of Stenamma in Britain. It seems that
the newly recognised species S. debilis is in fact far more common than
S. westwoodi. The maps for S. westwoodi will have to be completely revised.
There is concern over the survival of some species in Britain. For example Formica
pratensis, one of the "Wood ants", may already be extinct and other species such as
F. exsecta have undergone a dramatic decline. There is also apparently a worrying
decline in the common Wood ant F. rufa, particularly in the north of its range. This is an
uncommon species in Essex with its stronghold in the woods of south-east Essex. There
is an old record for Epping Forest and there are old records for the north-east of the
county, the most recent being at Weeleyhall Wood in 1980. The Wood ant requires open
heathy areas within the woodland, and regular coppicing is an important factor in
providing suitable conditions.
On the other hand some other species have recently been shown to have a more
widespread distribution than previously thought. Myrmica specioides was originally
found in Kent at Sandwich Dunes. It was then discovered in a small number of other
coastal localities in south-east Kent and more recently in a wider variety of sites in that
county. In the last two years it has been found to occur in Essex and the south east of
Suffolk. One theory is that the ant is spreading, perhaps helped by the succession of mild
winters and good summers that we have had. However the species is also very close to
the common species M. sabuleti and M. scabrinodis and could well have been be
overlooked. It seems to occur in warm situations where the vegetation is short and there is
plenty of bare ground. It has been found in sandy areas for example at Colne Point and in
short grassland areas, particularly in old grazing marsh grassland and on south facing
slopes.