The Essex Naturalist
15
which is restricted to this tree. Throughout August, leaving the living-room
light on and the window open is likely to attract the very common and
widespread Wesmaelius subnebulosus - usually in the unicolorous melanic form
melancholica which seems to prevail in the south-east.
Less frequent, but perhaps no less common, are two species of Micromus - M.
paganus and M. variegatus. Both these species are thought to feed on root aphids
and they are most frequent along old hedgerows, woodland margins and in other
edge habitats. After these come the species which are seldom reported. Some of
these are restricted by habitat and so are less often encountered in gardens but
this does not necessarily mean that they are rare. Wesmaelius concinnus should be
looked for on Scots pine trees Pinus sylvestris whilst Hemerobius atrifrons and
Wesmaelius quadrifasciatus are confined as larvae to larch trees Larix decidua. The
usual Neuropteran life-cycle, exemplified by the Coniopterygidae, already
mentioned, is adopted by the family with a few minor variations between species.
It is, however, the green lacewings that are perhaps the most familiar to
people here this afternoon. Unfortunately, most of the nineteen British species
look remarkably similar and their identification can cause many problems -
particularly on the continent of Europe where there are rather more. Sixteen
species are noted for Essex, but the one which most people will come across
most frequently is Chrysoperla carnea - the common green lacewing. This is the
one found indoors in the winter, being the only one that hibernates in the adult
phase of its life cycle. In reality it is now known to comprise two species - C.
carnea sensu stricto and C. lucasina - and we have both in Essex though at the
present moment I am not able to comment on the status of either. Essex can
boast a green lacewing which is currently not known from anywhere else in
Britain. The large Nineta inpunctata was taken for the first and only time in
Britain in a light trap at Eastend Wood, near Stansted Airport in 1989 (Plant,
1996). It is either extremely rare or else very hard to find throughout Europe,
being known from only 15 localities in the West Palaearctic Region.
Mecoptera
Britain's impoverished Mecopteran fauna comprises only four species in two
families. We have three scorpion flies (Panorpidae), in the form of Panorpa
communis, P. germanica and, rather less commonly, P. cognata. and the snow-
flea, Boreus hyemalis; all occur in Essex.
B. hyemalis is a particularly interesting insect because it is mature as an adult
in mid-winter - it may be best found from about early December to the end of
January. There is strong sexual dimorphism, the male wings being modified into
two stiff spines which support the wingless female on his back during mating.
Although adults can be seen leaping around on the snow in some years, pitfall
traps represent a better way of finding them.
Our three scorpion flies are remarkably similar and can only be reliably
separated from each other by examination of the male genital capsule or of the