Ground beetle (Anisodactylus poeciloides)
|Size||Body length: 9 - 12 mm|
Classified as Rare in the UK.
This beetle is of 'medium' size (in beetle terms), with an attractive colouration and the 'typical' ground beetle shape. The colour ranges from bright metallic green to purple, but occasionally black specimens are found. It closely resembles several other ground beetles.
In Europe, the beetle is found along the western coasts, from Germany to northern Spain, although it is recorded from salt-water lagoons at inland locations in south east Europe. In Britain, its range is presently confined to the south east coast, in Essex, Kent and south Hampshire, but before 1970, it extended from Essex, around the southern coast, to Cornwall.
This beetle is now known to be essentially a coastal species. It is found on saltmarshes, often where there is grazing land behind, and close to brackish dykes and lagoons. It shows a preference for the margins of these wet areas, with scattered areas of low-growing vegetation.
This species is a seed eater, sometimes climbing tall vegetation such as the common reed in order to feed. It is nocturnal in its habits, possibly to avoid predation by frogs. The beetle has an annual life-cycle, breeding in spring, and the larvae feed during the summer months before pupating and spending the winter in tussocks.
The beetle is thought to be under threat from several factors. Industrial development along the busy south-east coast line of England is reducing the amount of saltmarsh available as habitat. There is also the problem of erosion and the construction of sea defences, which have wiped out many of the beetle's former sites. The high levels of grazing on some of the coastal marshes are also thought to have contributed to the decline of this beetle.
Anisodactylus poeciloides is listed in the UK Biodiversity Action Plans and included in English Nature's Species Recovery Programme. The initiative 'Action for Invertebrates', has commissioned a number of surveys along the south coast to establish the extent of the populations of this beetle. Early reports suggest that it might not be quite as rare as was thought. In 1999, one was found on the shore of Dibden Bay at the mouth of the river Test in Hampshire. This record was the first since the 1920's from anywhere west of Sussex, and it has prompted interest in surveying some of the neighbouring areas where the beetle was known to occur in the 19th century.
There is still a threat to this species, however. Coastal development is proceeding apace along this busy part of England, and as of 2002 there were proposals to build a large port at Dibden Bay. This development, if it goes ahead, will pose a serious threat, not only to the beetle, but many other coastal species as well.
Information supplied by English Nature.
- Larvae: stage in an animal's lifecycle after it hatches from the egg. Larvae are typically very different in appearance to adults; they are able to feed and move around but usually are unable to reproduce.
- Pupating: the process of becoming a pupa, the stage of an insect's development, when huge changes occur that reorganise the larval form into the adult form. In butterflies the pupa is also called a chrysalis.