10
and to ask for help in resolving some outstanding
puzzles.
For my purposes in this article the term 'dragon-
flies' includes both dragonflies in the strict
sense (the Anisoptera) and the usually smaller
and more delicate damselflies (Zygoptera).
Together these groups make up the order Odonata.
It is generally accepted that there are thirty-
eight species of Odonata which breed in Britain,
a further three having become extinct this century,
Reliable records in Essex since 1975 suggest
that we now have at least twenty-one breeding
species, with a further three species which have
been recorded in the County during this period,
but whose breeding status is uncertain. This
ratio, of the order 55% to 65% of the national
total tallies very closely with other groups
of organisms which have now been thoroughly
surveyed (such as the Lepidoptera).
Like the national Odonata fauna, the Essex
dragonflies, too, have declined in numbers this
century. Historical comparisons are extremely
difficult, of course, because intensive county-
wide surveys of the type now going on have not
been attempted before. Nevertheless, Essex has
been blessed by the work of several entomologists
of national reputation, such as C.O. Hammond,
Cynthia Longfield and E.B. Pinniger, as well as
important earlier figures such as the Harwoods
who collected in the Colchester area around the
turn of the century. Their records suggest
that at no time since about 1915 have there been
more than some twenty-six breeding species of
Odonata in Essex, though there are nineteenth
century records of several more species associated
with acid bog, as well as two further species
associated with moving water habitats which are
now very scarce nationally. It seems, then,
from the limited evidence available, that the