151
Procas armillatus (Fabricius)
Smicronyx reichi (Gyllenhal)
Scolytidae
Ernoporus tiliae (Panzer)
Lymantor coryli (Perris)
My database includes Essex records that I regard as probably reliable for some 2507 beetle
species, or around 62% of all species reliably recorded as resident in the British Isles. There arc
Essex records that I regard as particularly suspect for an additional 28 species. 7 of which arc
included in Table 1 above. The Essex records for 17 of these 'doubtful' species (including all of
the bracketed species in Table 1) are probably based on misidentifications; the localities from
which 4 further species have been recorded are probably not within Essex, and the final 7
'doubtful' species are probably immigrants that are not native or established in the British Isles.
To put the summary data in Table 2 into some context the distribution by date class of records
for all species in my Essex beetle database are of some relevance. Essex records for the pre-1900
period pertain to a total of 1805 species, in the 1900-1949 period 1876 species, and in the post-
1949 period 1923 species. There arc thus 584 species (or 21.4% of the total) known to have
occurred in the county for which post-1949 records are lacking.
Table 2. Coleoptera species with high U.K. conservation status. The Essex figures omit
those species (in square brackets in Table 1) for which records are particularly doubtful.
RDB1 RDB2 RDB3 RDBI RDBK Extinct Total
U.K. total 154 57 114 122 250 64 761
Essex total 31 17 57 15 45 7 172
Essex 1900+ 18 13 48 12 35 - 126
Essex 1950+ 11 7 41 4 20 - 83
Essex 1970+ 5 3 22 2 17 - 49
Data (summarised in Table 2) for the species of high conservation status, not suprisingly, present
a different picture, with far greater proportions of the species lacking records for more recent
periods. Post-1949 records are lacking for more than half of these species (51.7%), post-1969
records are lacking for more than two-thirds (70.2%), and a substantial number (26.7%) have not
been found in Essex this century.
Just how reliable is this picture of decline and disappearance of species from the county? At
least 7 of the species listed in Table 1 are generally considered, on reasonable grounds, to be
extinct in the British Isles as a whole. Bearing in mind patterns of decline observed in other
counties, and the pattern of relevant habitat loss within Essex itself over the past hundred years
or so, I would expect around half of the 123 high status beetle species once known to have been
found in Essex but not reported from the county since 1969, to no longer occur there. There is
no space here to attempt any justification of this contention but, by implication, there remain al
least 60 or so of these species that have not been recently reported from the county, but may well
be found if searched for in appropriate locations.
Essex Naturalist (New Series) 16 (1999)