hundred and ninety-two) 5 km. squares have been visited in search of dragonflies. At
least some records have been obtained from one hundred and seventy-nine of these
(Fig. 1:1). Ten species or more have been recorded from each of thirty-eight 10 km
squares, and as many as twenty-one from one of them (Fig. 1:2). The figure for the 'basic
five' species stands at forty-two squares (Fig. 1:3). During the survey, twenty-six species
of dragonfly were recorded, though at least four of these appear not to be breeding
species in the county. Distribution maps for the twenty-two species breeding in Essex
during the period of the survey (1980-87) have been prepared on a 2 km. (tetrad) basis.
Either directly or indirectly, through their submissions to the Essex Biological Record
Centres, some seventy recorders participated in the survey.