The current list of UK Biodiversity Action Plan (BAP) priority species was published in August 2007, following a 2-year review of the BAP process and priorities. The list now contains seven Auchenorrhyncha species which have been highlighted as priorities for conservation action. These were selected using criteria based on international importance, rapid decline and high risk.
montana (Scopoli 1772)
New Forest Cicada
This species is the only UK representative of the cicadas, a group of insects normally associated with much warmer climates. As anyone who has visited Mediterranean countries in summer will know, many cicadas produce very loud, sometimes ear-splitting, calls or ‘songs’; by comparison, the call of the New Forest Cicada is high-pitched and very faint so is often inaudible to people beyond the age of forty. Apart from a few records from Surrey woodlands in the nineteenth and early twentieth centuries, the species has been most consistently recorded from a handful of sites in the New Forest. However, there have been no reliable sightings of this species at its main historical site there since 1993 so it may well now be extinct.
Detailed research at the New Forest sites has suggested that it requires warm, south-facing micro-habitats within open-structured scrub, woodland glades and woodland margins. Eggs are laid in woody stems or branches of trees and bracken. The nymphs live underground, probably feeding on the roots of grasses, and may take six to ten years to mature to the adult stage. Long-term persistence at a single site may be the exception rather than the rule, since evidence from work by continental entomologists suggests that this species typically has transient local populations that track habitat patches as they become suitable, with considerable mobility between sites.
Adults and nymphs of the Pondweed Leafhopper feed on floating leaves of pondweeds. The only known host plant in Britain is Broad-leaved Pondweed Potamogeton natans, although the leafhopper has been recorded on other Potamogeton, Nuphar and Nymphaea species in other European countries. It is not known where the species lays its eggs or in what life-history stage it over-winters.
This species is currently known from only three sites (two in Sussex and one in Surrey), with historical records from another four widely-scattered sites in south-east England. It is extraordinarily vulnerable: it occurs in small populations, usually in small ponds, often outside sites managed for conservation, which are very prone to neglect or inappropriate management. The main threats are habitat loss and habitat degradation. It appears to be especially sensitive to water quality.
L-R: Cicadetta montana, Erotettix cyanae, Doratura impudica & Euscelis venosus
impudica Horvath 1897
A rare species confined to a specialised and very vulnerable habitat type: sparse pioneer vegetation (often Sea couch Grass Elytrigia juncea) on the seaward edge of coastal sand dunes. It has been recorded at a number of sites around the coast of East Anglia and south-east England from The Wash to Rye Bay in Sussex.
Its preferred habitat is vulnerable to dune erosion, public recreation pressure and inappropriate dune management (e.g. attempts to stabilize dunes by planting marram grass or constructing board-walks).
venosus (Kirschbaum 1868)
This species is strongly associated with tall calcareous grassland, of which it may be a good indicator species. It has been found at three sites in Britain, but the only recent record is of several individuals at St Catherine’s Hill, Hants in 1993. It seems to be universally rare, both in Britain and elsewhere in its European range.
The precise habitat in which it occurs (taller/rank grassland) is one whose importance tends to be overlooked on chalk grassland sites because it is often species-poor in comparison to short grazed swards. Consequently, this species could be very vulnerable to well-intentioned, but inappropriate, management.
|Eurysanoides douglasi (Scott 1870)
This is an exceptionally rare species that is apparently restricted to high quality long-established chalk grassland, of which it may be a good indicator species. It has been recorded from only four scattered localities in the extreme south-east of England: two in Kent and two in Sussex. The only two recent records (since 2000) are both from Sussex. It has not been recorded elsewhere in Europe.
Its detailed habitat requirements remain a mystery, since there are no obvious differences between the sites holding populations and other sites with apparently similar habitat that do not. The known sites have a varied vegetation structure and there is a possible association with tussocks of Tor grass Brachypodium pinnatum, although this may not be the host plant. In any case, it is reasonable to assume that management producing a uniform sward lacking such tussocks (e.g. through overgrazing) would be inappropriate.
|Ribautodelphax imitans (Ribaut
Another exceptionally rare species, recorded from only four sites in southern England, with only two records from the last 35 years. It seems to be most strongly associated with calcareous grasslands, or at least sites on a calcareous substrate.
Work in continental Europe suggests that it feeds exclusively on Tall fescue Festuca arundinacea, although which host plant species it uses in Britain has not yet been established. It may well require taller vegetation or tussocks within a variably structured grassland matrix.
|Chlorita viridula (Fallen
This species feeds on Sea wormwood Artemisia maritima, where it grows on the upper levels of salt marshes and sea walls. It has been recorded at over 25 localities, but all of them lie within a restricted geographical area: around the Thames Estuary (both the Kent and Essex sides) and the north Kent coast. It appears to be genuinely confined to this area, even though apparently suitable stands of the host plant occur widely around the south and east coast of England.
The area where it occurs is under constant threat from development and the construction or renovation of sea defences, or managed coastal retreat, which would result in the destruction of the host plant.