low density. Others may have been overlooked. Doubleday used to find Ectropis
consonaria (square-spot) high up on the trunks of hornbeam in the damp and
shady parts of the Forest: has it been looked for recently?
Some of the Sphingidae (54) are taken more commonly now than in the
past, because of the use of mercury-vapour light. However, Sphinx ligustri
(privet hawk) is currently scarce and my only recent record is of two larvae at
Loughton in about 1974 (A. R. Pittaway, pers. comm.). Of the day-flying
species, both the bee-hawks {Hemaris tityus and H. fuciformis) have gone and
are unlikely to return as their foodplants are scarce and the habitat somewhat
unfavourable. The migrant species occur from time to time in their un-
predictable manner, with Macroglossum stellatarum (humming-bird hawk) the
most regular visitor.
The Notodontidae (55), a family that comes readily to light, are well
recorded and are holding their own. Stauropus fagi (lobster) is a good example.
Odontosia carmelita (scarce prominent) has always been rare; Doubleday
recorded it on the evidence of a single wing found by his brother. There has been
a series of isolated records since, the latest in 1938, a pattern of incidence
suggesting that the moth has never been resident.
Two of the Lymantriidae (57), Euproctis chrysorrhea (brown tail) and
Leucoma salicis (white satin) were as erratic in their appearance in 1835 as they
are today; then as now they could be either scarce or appear in profusion. It is
surprising to find Doubleday describing the now common E. similis (gold-tail)
as "excessively rare". Lymantria monacha (black arches) has never been
common; it went from the Forest before the turn of the century and may now be
extinct in Essex.
In the Arctiidae (58), the Lithosiinae are at a very low ebb. Most of their
larvae feed on lichens which have now been destroyed by pollution. Yet the
footmen were in decline before pollution became acute, so the causes for their
scarcity are complex. Of the nine species recorded from Epping, only Eilema
lurideola (common footman) has furnished recent records. The Arctiinae are in
better shape but Diacrisia sannio (clouded buff) is unlikely to be recorded again
as there is insufficient true heathland for its needs.
The reason why there are recent records for 60% of the Noctuidae (61), but
only 48% of the Geometridae (53) is simple: more of the former come to light-
traps. In this family, too, there are casual vagrants unlikely to recur, such as
Calophasia lunula (toadflax brocade), taken only in 1817. However, there is also
a large group of moths which have not been recorded since 1950 but are almost
certainly still present. Among them are autumnal species such as Brachionycha
sphinx (sprawler), spring species such as Cerastis rubricosa (red chestnut) and
six species of Orthosia including the ubiquitous O. cruda (small quaker), and
overwintering species such as Lithophane ornitopus (grey shoulder-knot). Is it
not likely that the true decline is in the number of entomologists prepared to
make night visits to ivy or sallow-blossom, rather than in the moths themselves?
A species which appears to have gone from the Forest, but not from Essex, is
Elaphria venustula (rosy marbled), though it was common in some years in the
last century.
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