A number of moths have colonised Essex since records began to be kept, not a few of them in recent
years. Some have come from the Continent and others from elsewhere in this country. Some species
have been unable to establish themselves and have died out after a few years, but others have been
highly successful.
A well-known recent colonist from the Continent is that attractive small noctuid, the varied coronet
(Hadena compta). Apart from a few unreliable 19th century records, this insect with blackish and
white forewings was first noted in Britain in 1948 when several were taken at Dover flying round sweet
william (Dianthus barbatus). In 1953 the first specimen to be recorded outside Kent was taken at
Colchester, and in 1954 it was found commonly on a seed farm in the same area. Since then it has
colonised many parts of the county. Because of its choice of foodplant it is an insect of gardens and
nurseries.
Another successful colonist is Vine's rustic (Hoplodrina ambigua). This small noctuid with
clearly-marked greyish brown forewings and white hindwings was formerly virtually confined to the
south and south-west coasts, although it was first recorded in Essex in 1934. It began to extend its
range into the home counties in the 1940s and is now widespread in the county and is sometimes
locally abundant
The diminutive juniper pug (Eupitheciapusillata) is another recent colonist but one that may may
well have been imported into the county since ornamental junipers are now popular garden shrubs.
There are old records from Donyland and Woodford but otherwise it was unknown in Essex until
1955 when one was taken at Westcliff-on-Sea. During the past two or three years it has extended its
range markedly. Another juniper-feeder, the juniper carpet (Thera juniperata) seems to be following
in E. pusillata's footsteps as it has appeared in several Essex localities during the past few
years.
The lyme grass (Photedes elymi) is a very recent colonist It is unlikely to have travelled far,
however, as it is found on the east coast wherever its foodplant, lyme grass (Elymus arenarius)
flourishes. It was first discovered, in the extreme north-east of the county, in 1975 and is now known
to be established there. Lyme-grass has been increasing in that area for some years and the moth's
appearance was not, therefore, unexpected.
The most successful recent case of a native species colonising Essex concerns the dotted rustic
(Rhyacia simulans). Apart from a claimed occurrence in the 19th century (Doubleday, H., 1841),
this medium-sized grey-brown noctuid was unknown in the county before 1974, when one appeared
near Brentwood. In 1978 a total of ten were recorded in Essex and by 1984 it had appeared in no fewer
than 39 10km squares scattered throughout the county and is now firmly established.
Not all colonists succeed in gaining a permanent foothold in the county. A case in point is the black
V moth (Arctornis l-nigrum). This quite sizeable white moth with a shallow ' V mark on the forewing
is normally an extremely rare visitor to Britain, yet it became established in the Bradwell-on-Sea area
for a period of 14 years, from 1947-60. Peak numbers (15 in each year) occurred in 1950 and 1956,
and a single larva was found on elm in 1953. As far as is known, none has since been recorded
anywhere in Britain.
Essex has its share of pest species, the best-known of which is the brown-tail (Euproctis
chrysorrhoea), a white moth with an anal tuft of brown hairs. Regarded as a predominantly maritime
species in Britain, where it is practically confined to the English coastal counties in the east and south,
the brown-tail is found all round the Essex littoral and is quite widespread, although at much lower
density, inland. Essex is perhaps the species' stronghold in Britain and periodically it attains
abundance in certain coastal and estuarine localities, chiefly along the Thames estuary and on
Canvey Island. Its hairy larvae cause considerable damage to hawthorn and blackthorn hedges and
are regarded as something of a health hazard as their hairs can cause irritation if they come into
contact with the human skin. Consequently the authorities felt it necessary some years ago to take
powers to control the insect on private property in what is now Castle Point district, and provision to
this end is contained in the Essex County Council (Canvey Island Approaches, etc.) Act, 1967. At
the time of going to press we learn that powers are being sought to extend these control provisions to
the whole county. It is hoped that any extended powers will be exercised with the greatest restraint and
care as, of course, control measures are bound to destroy other larvae too. At the same time, it must be
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