Another insect which is proving to be quite widespread in Essex is the maple prominent
(Ptilodontella cucullina). It is regarded as a local species in Britain and is said to be found chiefly on
chalky soil (Heath et al, 1979). Thus it cannot be considered a typical Essex insect although its host
tree, maple, is found almost throughout the county. Up until quite recently it was thought to be very
local but it is now known to occur in a surprising number of localities (35 squares). Probably it was
never as local as the earlier lack of records suggests, but there seems little doubt that it has been
extending its range for some time.
Essex has lost a number of moth species over the years. One of them is the small ranunculus
(Hecatera dysodea). Formerly a very local species, it was at one time well represented in Essex,
particularly in the Coggeshall district where the larvae fed on the blossoms and seed-heads of lettuce.
It is now almost certainly extinct in Britain. But others return from the brink, even though conditions
today are far less favourable than they once were for species to re-establish themselves. A case in
point concerns the handsome black arches (Lymantria monacha) which is primarily an oak-
woodland species. The Guide was unable to cite a single occurrence during the period 1961-74
(although a 1964 record was received subsequently), yet it has since been reported, occasionally in
some numbers, from no fewer than 12 10km squares, in some of which it has been found in more than
one locality.
We next turn to immigrant species, a number of which visit Essex, although comparatively few are
of annual occurrence. Among the best-known immigrants are several species of hawk-moth including
the convolvulus (Agrius convolvuli) and death's-head (Acherontia atropos). Our largest British
moths, they are magnificent creatures with a wingspan of up to five inches. The convolvulus is
probably of annual occurrence although it is usually scarce or very scarce. The death's-head is so
named because of the likeness of a skull on its thorax. It is even more irregular in its appearance; it
usually lays its eggs on potato leaves and because of the wholesale spraying of potato crops the huge
larvae are now rarely seen, though several were reported in 1984. There can scarcely be a more
unusual record of the death's-head hawk-moth than that of one which emerged in a dazed condition
from a spin-drier in a house at Ramsden Heath in 1974. The insect must have come to rest on washing
that had been put out to dry overnight but had been returned to the drier, and respun, the next morning!
Incidently, our largest resident moth is the privet hawk-moth (Sphinx ligustri). It is still widespread in
Essex (recent records in 37 squares) but there are signs that it may be in decline.
An annual immigrant, the humming-bird hawk-moth (Macroglossum stellatarum), is so named
because of its striking resemblance both in appearance and behaviour to a humming-bird. It is a day-
flier and can be seen extracting nectar from flowers with its long tongue whilst hovering on rapidly-
beating wings. This interesting insect used to be very numerous in some years but its numbers have
declined and now it is usually scarce or very scarce. However, sizeable numbers have appeared in four
recent years, including 1982-84.
The most abundant immigrant moth is undoubtedly the silver Y (Autographa gamma), so called
because of the silvery Y-shaped mark on the forewing. In most years it penetrates in numbers to all
parts of the county but it is always most numerous on the coast where, in late summer and autumn, it
becomes abundant at times: for example, over 7000 entered A. J. Dewick's light-trap at Bradwell-on-
Sea one night in September, 1960 and 100,000 were estimated at Colne Point Nature Reserve in
August, 1969. Yet it is almost certainly less abundant today than formerly, as Harwood (1903)
records that in 1900 the moths were rising " in clouds at every step for several miles" near Clacton-on-
Sea.
In addition to Gortyna borelii already mentioned, two Essex moths have been named after Essex
lepidopterists. Mathew's wainscot (Mythimna favicolor) was discovered at Dovercourt in 1895 by
Paymaster-in-Chief G.F. Mathew, RN (Mathew, 1905). Mathew was convinced that the wainscot
moths with smooth, honey-coloured forewings which he had found resting on marsh grasses were
distinct from the common wainscot (M. pallens), and the species was decribed and named by Charles
Barrett (1896). The insect appears to be confined to eastern and southern England, where its
distribution, as in Essex, is mainly coastal. It is unknown outside Britain.
The first British example of the very rare migrant, Macdunnoughia confusa, a close relative of the
silver Y, appeared at Bradwell-on-Sea in October 1951 and was named Dewick's plusia after its
finder. It occurred again at Bradwell in 1955 and 1982.
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