North and south coast invertebrates group

Beautiful gothic, Paul Burgess

A variable meadow fly sits on a shiny green leaf. The fly has six yellow legs, a black and yellow striped abdomen and body, as well as clear light brown wings that lie flat parallel to the body. The large black eyes sit above a bright yellow mouthpart and between them are two short, stout, black antennae.

Variable meadow fly, John Walters

1. About

The cliffs, coastal grasslands, shingle and rocky shores along Devon’s two coastlines support a wealth of wildlife, including rare invertebrates. Many of these are very specialist and rely on coastal plants, such as thrift and sea campion. Others were once more widespread but are now largely restricted to wildlife-rich coastal habitats.

This group includes species which are largely found scattered on the north coast and the south coast (largely west of the Exe). Unique groups of coastal invertebrates are found on the slumping chalk cliffs of East Devon, Start Point to Bolt Tail, sand dunes and in intertidal areas. These mixed groups are discussed separately. Unique groups of invertebrates found in very specific locations are discussed on the relevant species page e.g. Torbay limestone moths, Dawlish Warren mudflat flies.

Devon Special Species scattered along both coasts are discussed below. There are lots of other invertebrates found along Devon’s coasts which are listed as Devon Species of Conservation Concern. These include the black mining bee (Andean pilpes).

Key pressures and opportunities

Consultation question: are there other pressures along this stretch of coast e.g. development, recreation, climate change, nitrogen?

Lack of grazing is causing a loss of sunny, open and bare ground and allowing shrubby vegetation such as gorse and bracken to become dominant. Some tree planting schemes are also causing habitat loss. However, organisations such as the National Trust and projects such as Life on the Edge are reintroducing grazing. See Inspiration below.  

The conversion of flower-rich cliff-top grassland to intensive arable production has in the past led to loss of invertebrate habitat. Cultivation close to the cliff edge continues to be a problem in some areas.

The use of increasingly powerful biocides and pesticides on farmland adjacent to wildlife-rich habitats on the coast is having a harmful effect on invertebrates.

In some parts of Britain, invasive members of the South African plant family Aizoaceae have colonised coastal cliffs. The main problem species is hottentot-fig (Carpobrotus edulis), which is well-established at Croyde Bay in north Devon. It’s also been recorded on the south Devon coast and could become a problem.  The garden rose Rosa rugosa is spreading on the south Devon coast. This is not yet a significant problem but as for hottentot-fig could rapidly spread and become a significant problem for native wildlife.

Life on the Edge is funded by the National Lottery Heritage Fund. The project focuses on the rare invertebrates and plants found along the south Devon coast and provides huge opportunities for nature recovery over the next few years. See Inspiration below.    

2. What we need to do and where

Devon Special Species

A variable meadow fly sits on a shiny green leaf. The fly has six yellow legs, a black and yellow striped abdomen and body, as well as clear light brown wings that lie flat parallel to the body. The large black eyes sit above a bright yellow mouthpart and between them are two short, stout, black antennae.

Variable meadow fly

Chrysotoxum elegans

The variable meadow hoverfly uses its yellow and black stripes to mimic wasps. It lives in open, sunny, flower-rich coastal grasslands. It’s largely found along the south Devon coast but also occurs in a few places along the north coast.   It’s an attractive species and can act as a flagship for the management of coastal grasslands. 

The variable meadow fly is nationally scarce and thought to be declining across the country due to loss of habitat. As for other species in this group, a key issue is loss of coastal grasslands due to lack of grazing.   

Lizard weevils

Cathormiocerus attaphilus, Cathormiocerus maritimus and Cathormiocerus myrmecophilus.

These brown, flightless weevils (a beetle) are rare and only found on the Atlantic fringes of western Europe. They’re named after the Lizard peninsula in west Cornwall.  

Lizard weevils are parthenogenetic, which means their populations consist entirely of females that lay eggs which don’t need to be fertilised.  

There are three species in this group, Cathormiocerus attaphilus, Cathormiocerus maritimus and Cathormiocerus myrmecophilus. They’re all largely found in Devon and Cornwall, with some records along the south coast of England and Wales. C. attaphilus is especially rare and found only in Devon and Cornwall.

They need short maritime grassland with patches of bare ground maintained through exposure to salt spray, erosion, grazing and thin, dry soil. They’re thought to feed on a range of plants but seem to prefer plantains. The key pressure is tall grassland and scrub caused by a lack of grazing.  

In Devon, all three are found between Wembury and Prawle Point. C. maritium and C. myrmecophilus are also found between Brixham and Froward Point (near Kingswear). C. myrmecophilus is also found on the north coast between Marsland and Clovelly.   

Devonshire wainscott and other coastal moths

This group includes species which are largely found on the cliffs, coastal grasslands, shingle and rocky shores along Devon’s two coastlines. Some are very specialist and rely on plants, such as thrift and sea campion, which only occur in coastal areas. Others were once more widespread but are now largely restricted to wildlife-rich coastal habitats.

Moths which are characteristic of sand dunes, east Devon chalk and Torbay limestone are discussed in separate groups.

Devon Species of Conservation Concern include:

  • South coast only:
  • Sea spurge tortix (Acroclita subsequana). Caterpillars feed on sea spurge and Portland spurge, spinning the leaves to the stem with silk. In Devon they’re recorded at Strete Gate Beach in Slapton. 
  • Rolled grass moth (Pediasia conteminella). The caterpillars feed on grasses such as sheeps’ fescue. In Devon they are recorded at a few locations on the south Devon coast, the sand dunes at Dawlish Warren and a few records from the Pebblebed Heaths.
  • Both coasts:
  • Black banded (Polymixis xanthomista). Recorded along the north coast between Ilfracombe and Hartland and scattered along the south coast.  Restricted to rocky and stony areas where they feed on coastal plants such as thrift.
  • Barrett’s marbled coronet (Conisania andalusica). Recorded along the south coast and on the north coast between Ilfracombe and Hartland. Caterpillars feed on the roots of sea campion and rock sea-spurrey.
  • Scarce moss moth (Bryotripoha dryadella). Caterpillars feed in silk tubes woven among moss. Recorded in Torquay, Berry Head, and Hartland.
  • Thrift clearwing (Pyropteron muscaseformis). Found on rocky shores and cliffs around Hartland and on the south coast where caterpillars feed on the stems and roots of thrift.
  • Garden tiger (Arctia caja). Still widespread but declining and now only common in coastal areas. Caterpillars feed on a wide range of plants.
  • Lundy only:
  • Cornish snout (Nothris congressariella). Caterpillars feed on balm-leaved figwort, which has a very localised distribution.  The population is thought to have expanded following rhodedendron eradication.

Three species are identified as Devon Special Species in their own right.

Devonshire wainscott

Leucania putrescens

Caterpillars feed on various grasses through the winter and pupate in May. They’re known to be along the whole Devon coastline (including east Devon) with a few recorded inland. 

Beautiful gothic

Leucochlaena oditis

Restricted to the south coasts of Devon and Cornwall and the south-west coast of the Isle of Wight. In Devon it’s been recorded at various sites heading west from Torbay. Caterpillars feed on grasses including common couch and, during the winter, annual meadow-grass.

Scarce black neck

Lygephila craccae

Recorded in north Devon from Hartland Point to Woody Bay. Caterpillars feed on wood vetch and tufted vetch.

Actions

Manage and restore (through light grazing and scrub control) a mosaic of connected habitats with flower-rich grasslands, bare ground, scattered scrub and trees, wet seepages, eroding cliffs, shingle and critical foodplants.

Monitor and control invasive species such as hottentot-fig and rugosa rose.

Minimise the use of, and target applications of, pesticides and avermectins to reduce impacts on invertebrates.

Other relevant actions

See the Coast page for other relevant actions and coastal species.

Where to focus action

High Opportunity Areas: All Coastal Wildbelts. See Mapping.     

3. Inspiration

To add following discussion during Consultation. Please share any case studies for this group.

Case studies

National Trust? Life on the Edge?

Where to visit

SW Coast Path  

4. Find out more

To update following discussion during Consultation.

See the main species pages for links to useful information including recording schemes: Moths, Flies, Beetles.

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