Millenial Status in Essex of Nationally Scarce and Threatened Species of Coleoptera 189
Discussion
The data contained in Table 1 along with data on high scarcity/threat status species dealt with in the
previous paper (Hammond, 1999) are summarised below in Table 3. Excluding the 64 species now
considered to be extinct in the U.K., the summarised data reveal that some 45% of the beetle species
considered to merit a national scarcity /threat status have been reliably recorded, at one time or
another, from Essex. 37% of the scarce/threatened British species have been reliably recorded from
the county since 1900, 27% since 1949, and just under 20% since 1969. A very subjective assessment
of these data suggests that had no species actually present in the county remained undetected, these
figures would be substantially higher. Indeed, although only 341 of the scarce/threatened species
have been reliably reported from Essex since 1969, the number of these species still present in the
county is quite likely to be double that figure. To select a few scattered examples, it would be very
surprising if such species as Omalium rugatum, Philonthus pseudoparcus, Oxypoda amoena, O.
recondita, Meligethes incanus, Synchita humeralis, Cis festivus, Phaedon concinnus and Xyleborus
dispar were not still to be found in Essex. However, the task of investigating and confirming the
continuing occurrence of these species in the county is a considerable one, as many of them are
extreme habitat or microhabitat specialists not likely to be detected by every-day collecting techniques.
Not surprisingly, the picture painted by the summary presented in Tabic 3 differs in detail from one
category of species to another. For example, some 21% of U.K. beetle species in the highest category
(RDB1) have been reliably reported from Essex but only 3% or so of RDB1 species have been
found here in the most recent (post-1969) period. The picture for lower status species is very different.
For example, 69% of the lowest status (Nb) species have been recorded from Essex and, despite the
inadequacy of the recording effort, 37% of the U.K. species categorised 'Nb' have been reliably
reported in the county since 1969.
Table 3. Coleoptera species with high conservation status.
The Essex figures omit those species (in square brackets in Table 2 and in square brackets in
Hammond, 1999: Table 1) for which records are particularly doubtful.
RDB1 RDB2 RDB3 RDBI RDBK Extinct Na Nb N Total
U.K.total 154 57 114 122 250 64 259 548 234 1802
Essex total 34 18 58 15 54 7 124 379 108 797
Essex 1900+ 18 14 50 12 43 - 96 330 92 655
Essex 1950+ 11 8 42 4 25 - 68 266 62 486
Essex 1970+ 5 4 22 2 21 - 49 205 33 341
Any very detailed analysis of the results presented here in terms of what they may indicate with
respect to future recording efforts and their possible implications for conservation efforts is scarcely
warranted by the quality of the data. Suffice it to say on the first count that many different parts of the
county, habitat types and microhabitats are in need of further investigation if a really accurate picture
of the current situation viz-a-viz beetle species in Essex is to be obtained. The use of specialist
collecting techniques (e.g. for sampling the subterranean fauna), and of modern devices (e.g. large-
area flight interception traps that are effective in sampling species living in "cryptic" situations such
as the fruiting bodies of truffles and slime-moulds) will be of great service in achieving this aim. To
the extent that the data summarised here do give a reasonable idea of which elements of the beetle
fauna have suffered the greatest declines and may be under the greatest continuing threat, a few final
Essex Naturalist (New Series) 17 (2000)