Snake-flies, alderflies, lacewings and scorpion flies in Essex
Fig. 1. Coincidence map of all records of all species recorded in Essex.
National status codes
Peter Kirby provided an extremely valuable first review of the status of British Neuroptera and
allied orders based on data available to him in 1989 (Kirby 1991). Inevitably, however, data gained
via the lacewing recording scheme, established in 1988, have altered our state of knowledge
considerably since then and effectively rendered several of Kirby's formal status codes out-of-date.
In order to reflect this, a number of informal changes to national status codes were proposed later by
me (Plant 1994). However, yet more data flowing in via the national recording scheme has shown
that these revised codes, too, are not entirely correct and further revision is necessary. Such a
provisional revision was prepared by mc during April 2001, whilst writing an updated British lacewing
checklist for distribution with the recording programme MapMate. These proposals are not formally
adopted, of course; any such formal change is required to emanate from the offices of English
Nature. I have, therefore, provided two entries under the heading "National status": the first being
that of Kirby (1991) and the second, in parentheses, my suggested amendment at April 2001, thus:
National status: Existing formal status (Predicted status)
Regional (Essex) status codes
Harvey (1998) introduced the notion of Essex Rarity and Essex Threat categories using ants
(Hymenoptera; Formicidae) as his model. This system was later refined (Harvey 1999) using
harvestmen (Arachnida: Opiliones) as an additional model. Harvey's rarity categories were based
on the percentage of onc-kilometre squares (monads) that had actually been surveyed which contained
the species in the years since the end of 1979. These categories are summarised in Table 1.
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Essex Naturalist (New Series) 17 (2000)