spp.), the small copper (Lycaena phlaeas), common blue (Polyommatus icarus) and the six-spot
burnet (Zygaena filipendulae) are abundant in the uncut vegetation. Prior to the 1970s, the grayling
(Eumenis semelis) also favoured this habitat (Firmin & Pyman, 1975) but in recent years it has been
observed only once (1974).
Outside the sea-wall some uncommon Essex insects are found, many being totally dependent on
the specialised habitats found there.
The salt-marsh. There are several local moths which are dependent on the salt-marsh plants; for
instance, the saltern ear (Hydraecia fucosa) which feeds on the roots of the sea club-rush (Scirpus
maritimus), the grass-feeding crescent-striped (Apamea oblonga) and the Starwort (Cucullia asteris)
which feeds on the flowers of sea-aster. The ground lackey (Malacosoma castrensis), which is limited
to the south Suffolk, Essex and north Kent salt-marshes, has its strongholds at Colne Point and
Hamford Water. Interestingly, the eggs and larvae of the above four moths are all able to cope with
submergence by seawater, thus giving them access to the rich salting vegetation. One of the latest
additions to the macrolepidoptera of Essex, the sandhill rustic (Luperina nickerlii), has been found to
occur in abundance on the drier parts of the salt-marshes.
The shingle and sand ridges. The shingle ridges at Colne Point, particularly those topped with small
sand-dunes, provide an abundant food supply in the correct environment for a number of scarce
coastal moths. The archer's dart (Agrotis vestigialis), for instance, which has only a few Essex county
records, is quite abundant at Colne Point in early August, favouring the sand-dune grasses. The
closely related sand dart (A. ripae), another very local Essex moth, used to be abundant along the
entire coast between Harwich and Colne Point at the turn of the century, but it was noted as becoming
scarce by Gilles (1933). Colne Point and Hamford Water are now probably its only Essex sites. It is
well established at Colne Point where the favoured foods are the roots of sea-rocket, sea-holly
(Eryngium maritimum) and oraches. The larvae hibernate from October onwards buried deeply in
the sand; they pupate in the spring. The Colne Point specimens range from white through to the pale
brick-red form which is typically found in the Devon localities. The white colon(Sideridis albicolon)
is more difficult to locate than the previous two spp., but small numbers are regularly identified at
Colne Point and, judging from recent records, this is the major Essex site. Of the recognised
foodplants, the bright green larvae apparently favour oraches. This is unfortunate, as on occasion
numbers of larvae are found associated with this plant on the high-tide line. In the winter, when the
larvae are hibernating, the high-tide mark suffers severe erosion, a factor possibly accounting for the
dramatic difference in the populations of the sand dart and white colon at Colne Point, the former
showing less obvious preference for oraches. The tawny shears (Hadena perplexa) is extremely
common on the reserve, the purple larvae feeding on sea-campion. The adults, which are on the wing
throughout the summer, are rather variable, ranging from pale whitish to dark brown. The feathered
ranunculus (Eumichtis lichenea) and the feathered brindle (Aporophyla australis) are also seen at
Colne Point. The former is observed every year, usually during the August-September period, and is
probably well established. The feathered brindle, which occurs in only a few sites on the English east
and south coasts, has Colne Point as its only recorded Essex site. The moth, which favours sea-
campion, has been observed only on a few occasions but is probably established on the reserve.
Migrants. These can always be found in the summer months at Colne Point even in years when such
movements are light Thus whites (Pieris spp.), the red admiral (Vanessa atalanta) and the painted
lady (Cynthia cardui) are regular and in some years can reach large numbers (Cole, W., 1903). In the
last decade the convolvulus hawk-moth (Agrius convolvuli) and humming-bird hawk-moth
(Macroglossum stellatarum) have been observed on several occasions. Of course, the silver Y
(Autographa gamma) is one of the most common moths on the reserve, reaching enormous numbers
in some years. An estimated 100,000 were reported on a single August day in 1969, feeding and
resting on the coastal vegetation (Firmin & Pyman, 1975).
During this century, expansion of seaside towns and holiday camps, together with the construction
of marinas, has destroyed much of the Essex coastline. Each year more and more people explore the
coast for pleasure, placing tremendous pressure on the few remaining truly wild areas. In recent years
the Essex Naturalists' Trust has done much to preserve many of these coastal areas. Colne Point
Nature Reserve is owned and managed by the Trust.
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