Overall then, the survey results have been pleasing, the average number of species
recorded per 10km square being above eight whilst over a third of the 10km squares
boast ten species or more (see Table 2). The southern counties of Britain with ten or
more native species per 10km square are thought of as being notable, whilst five native
species per 10km square is regarded as average. Applying these figures to Essex
means we have at least an average number of Orthoptera for every 10km square, with
twenty-one squares in the notable category. It should be borne in mind that a tiny
proportion of these records, in Tables 1 and 2, refer to Acheta domesticus which is an
introduced species. Only twenty historical 10km square records, could not be refound in
the current survey, several of them being extremely old records of nationally rare species
such as Gryllotalpa gryllotalpa.
If further recording is undertaken, there are several species on which to concentrate.
Both the groundhoppers (mentioned above) are much under-recorded whilst Omocestus
viridulus may well occur more frequently than my records suggest, particularly in the
western half of the County. Chorthippus albomarginatus is spreading out from estuarine
marshes and could well be found in dry grassland, well inland from coastal areas.
Two species continue to extend their range nationally - Metrioptera roeselii and
Conocephalus discolor. Whilst M.roeselii is very common in several areas of the County,
it has yet to be found in the extreme north west and is well worth searching for there
despite poor habitat. As for C.discolor, the rate at which this species has spread across
neighbouring Hertfordshire, suggests it is well worth searching for in any scrubby or rank
vegetation anywhere in the County. All Essex records refer to 1995 only and it is most
likely to continue its rapid spread both eastwards and northwards.
There is every reason for future recorders to build on this survey.
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