Start Point to Bolt Tail Invertebrates

What we need to do and where
A six banded nomad sits on a grey rock facing the bottom right corner of the photo. It has orangey-yellow legs, oragey brown antennae, a black and yellow striped abdomen and a fuxxy black body and head. The dark, clear wings lay on top of one another against the abdomen, the large dark eyes are just below the antennae on on the head, and a lighter, yellowey mouthpart is just visible below those.

Six-banded nomad bee, John Walters

Against a grey fuzzy background, the moon spider is in the centre of the photo facing to the right. It has eight shiny, red-brown legs, a furry black abdomen with two broken stripes towards the rear, and the body is a shiny, hairy very dark brown-black. The head is not clearly visible but appears to match the main body.

Moon spider, R. Gallon

Devon red-legged robberfly, Nigel Jones

1. About

The unique geology of the coastline at the southern tip of Devon is home to an exceptional array of rare and unique invertebrates, some of which are found nowhere else in Britain. 

(Summary of geology and habitats to be added when we know how this relates to other pages and how people want pages to link / merge / whether plants are added here) 

There are five Focus Species in this group, four of which are also Devon Special Species, which reflects the special character of this stretch of coast.   

Other Focus Species invertebrates that are found on this coastline have a wider distribution and so are discussed in the North and south Devon coastal invertebrate group. These include Lizard weevils, the variable meadow fly and rare moths such as the Devonshire wainscott and beautiful gothic. The brown-banded carder bumblebee is largely found around Braunton but was re-discovered on this stretch of the south coast in  2022. See Bees, ants and wasps. 

Other Devon Species of Conservation Concern found along this stretch of coast include the golden lantern spider (Agroeca cuprea). They’ll all benefit from the actions below.  

Much of this area falls within either Prawle Point and Start Point SSSI or Bolt Head to Bolt Tail SSSI. However, many of the species in this group are not listed on the SSSI citations and may also rely on habitats that lie outside the SSSI.    

Key pressures and opportunities

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Habitat management

Lack of grazing is causing a loss of sunny, open and bare ground that is critical for many species in this group. Species are threatened by shading from scrub encroachment, particularly by blackthorn. 

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Climate change

Erosion keeps coastal head deposits open. Rising sea levels may accelerate this, with more storms causing larger and more frequent landslips. These conditions could be hard for invertebrates such as spiders and bees to adapt to, as suitable areas become more isolated and populations more likely to fluctuate.  

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Invasive non-native species

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.

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Life on the Edge

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

2. What we need to do and where

Priority

Increase the abundance and distribution of Focus Species along this stretch of coast. 

Focus species

A six banded nomad sits on a grey rock facing the bottom right corner of the photo. It has orangey-yellow legs, oragey brown antennae, a black and yellow striped abdomen and a fuxxy black body and head. The dark, clear wings lay on top of one another against the abdomen, the large dark eyes are just below the antennae on on the head, and a lighter, yellowey mouthpart is just visible below those.

Six-banded nomad bee and long-horned bee

Nomada sexfasciata and Eucera longicornis
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The six-banded nomad bee was once widely distributed across southern Britain but is now Britain’s rarest bee, restricted to a single site along the coast at Prawle Point. 

Nomad bees are known as ‘cuckoo bees’ as they lay their eggs in the nests of other bee species. The six-banded nomad bee is dependent on the long-horned bee which nests in bare soil on the warm, soft, south-facing cliffs and feeds on plants in the pea family such as everlasting pea and kidney vetch. Long-horned bees are still present in this area but are thought to be declining due to loss of suitable habitat. They’re listed as a Focus Species as they’re critical for the six-banded nomad bee. 

A devon red-legged robberfly sits on a grey rock against a blurred grey background. The fly has six reddy-orange legs, a mottled grey-brown round body with clear wings attached to it and lying flat against the slim brown abdomen which is roughly twice the length of the rest of the fly and has clear segments. Along the body are long, dark hairs. The small head is taken up by large grey eyes with short short antennae, below are the pale mouthparts.

Devon red-legged robberfly

Neomochtherus pallipes
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The first British record of this robberfly was in 1990 at Woodcombe, near Prawle Point. It hasn’t been seen since but there’s a strong possibility that it survives somewhere along the  coastal strip between Prawle Point and Start Point as due to its short flight period it’s easily overlooked. In 2016, the robberfly was found at a site in Shropshire but hasn’t been found anywhere else in England and is considered critically endangered. 

The robberfly lives on a mosaic landscape of small fields, soft cliffs, rank grassland, scrub and rocky knolls. It needs sandy soils and warm, open, south-facing slopes where it can bask on rocks in the sun. Its habitat is threatened by bramble and blackthorn, which due to a lack of grazing, have increased considerably at Woodcombe and at many other similar coastal sites.  

Against a grey fuzzy background, the moon spider is in the centre of the photo facing to the right. It has eight shiny, red-brown legs, a furry black abdomen with two broken stripes towards the rear, and the body is a shiny, hairy very dark brown-black. The head is not clearly visible but appears to match the main body.

Moon spider and other cliff spiders

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Nine species of rare spider live on the warm, sunny, sparsely-vegetated sediments between Bolt Head and Froward Point. Like all spiders, they’re predatory, feeding entirely on other invertebrates, including ants. All the sites for this assemblage fall within either Prawle Point and Start Point SSSI or Bolt Head to Bolt Tail SSSI.  No other county has records of all nine species in this assemblage.  

The rarest species is the moon spider (Callilepis nocturna), which is the Focus Species for this group. The jumping spider (Euophrys herbigrada) occurs more widely on the south coast between Cornwall and East Sussex. The ground spider (Micaria albovittata) has a similar range, and also occurs on some heaths a short distance inland. Other threatened spiders which occur here are also found in stony and sparsely-vegetated maritime grasslands. These are Acartauchenius scurrilis, Agroeca cuprea, Cozyptila blackwalli, Gnaphosa lugubris, Lasaeola prona, Phlegra fasciata and Zelotes longipes.  

Against a grey fuzzy background, the moon spider is in the centre of the photo facing to the right. It has eight shiny, red-brown legs, a furry black abdomen with two broken stripes towards the rear, and the body is a shiny, hairy very dark brown-black. The head is not clearly visible but appears to match the main body.

Moon spider

Callilepsis nocturna

This is the rarest spider in this group and in Britain is only found around Prawle Point and at single sites in Pembrokeshire and the Isle of Wight. Unlike other ground spiders, which are nocturnal, on sunny days the moon spider can be seen running over bare ground.  

Rather than spinning webs to catch its prey, the moon spider builds retreats, which (like those of E. herbigrada and M. albovittata) it lines with silk. It builds them on bare ground, under rocks and in burrows that have been abandoned by solitary bees. It’s been seen capturing ants and carrying them back to its retreat. 

The large, rotund, black oil beetle, appears to be sitting almost upright against a backdrop of short green grass. The beetle's large, long, round abdomen has faint segments along the whole length and comparatively tiny wing cases at the top where it joins the body. The body is roughly a tenth the size of the abdomen with the head being roughly the same size, apart from the large mouthparts. Both the legs and antennae have multiple obvious segments. Every part of the beetle is black.

Oil beetles

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Oil beetles are named for the bitter, oil-like fluid  they produce from their knee joints to deter predators. All British oil beetles are parasites of solitary mining bees.  Female oil beetles lay eggs in batches of up to 1,000, in burrows they dig into sparsely-vegetated soil. The eggs hatch into larvae known as triungulins, which climb into flowerheads and hitch a ride on the backs of solitary bees. Once in the bee’s nest, the larvae feed on the bee’s eggs and stores of pollen and nectar. 

Oil beetles are largely found on flower-rich coastal grasslands where their host mining bees are found.     

The large, rotund, black oil beetle, appears to be sitting almost upright against a backdrop of short green grass. The beetle's large, long, round abdomen has faint segments along the whole length and comparatively tiny wing cases at the top where it joins the body. The body is roughly a tenth the size of the abdomen with the head being roughly the same size, apart from the large mouthparts. Both the legs and antennae have multiple obvious segments. Every part of the beetle is black.

Mediterranean oil beetle

Meloe mediterraneus

This rare species is only found in Devon and Sussex. The main Devon population lies in the Prawle Point and Start Point SSSI, but has also recently been found on the East Devon Pebblebed Heaths SSSI and Bolt Head to Bolt Tail SSSI. They  are active on mild nights between September and April and have been observed feeding on leaves of soft grasses and buttercups.  

Short-necked oil beetle

Meloe brevicollis

In Devon the short-necked oil beetle is mainly found in the Bolt Head to Bolt Tail SSSI. itotherwise occurs in the outer Hebrides, Wiltshire and Pembrokeshire. Adults can be seen in the day from March to June, often feeding on leaves of hawkbits and other yellow dandelion-like species. 

Actions for all Start Point to Bolt Tail Invertebrates 

Survey and monitoring  

Monitor and research these species to inform conservation action.    

Manage and restore a network of flower rich grasslands with scattered scrub and trees, managing microhabitats for rare invertebrates.  

  • Manage (through light grazing and scrub control) and expand a connected mosaic of flower-rich grasslands (including legumes such as the everlasting pea and kidney vetch).   
  • Allow natural cliff erosion processes to continue.  Stop scrub encroaching on the head deposits that support rare spiders.     

Habitat management

Where to focus action

The Start Point to Bolt Tail Coastal Wildbelt. See Mapping.

3. Inspiration

Case studies

Life on the edge

Life On the Edge is funded by the Heritage Lottery Fund. The project works with the National Trust, farmers, communities and wildlife experts to reverse the decline of rare species, including those listed above. It focuses on five hotspots: Wembury, the Erme, Bolt Head to Bolt Tail, Prawle Point to Start Point, and Brownstone to Berry Head. 

Life on the Edge an introduction

Where to visit

Always follow the Countryside Code and stick to footpaths and sites that are managed for public access.  

Sites that are accessible to the public and are good places to see Start point to Bolt tail invertebrates include: 

Bolberry Down

Bolberry Down is managed by the National Trust. It has a cliff top car park and a section of the coast path that’s accessible by wheelchair. It’s the easiest to access section of Bolt Tail to Start Point and has stunning views and a café. 

Prawle Point

With crumbling cliffs and wildflower-rich cliff tops, the gorgeous landscape at Prawle Point is a great place for bug watching.  

For information on these and other sites that are open to the public please see the Explore Devon website.    

4. Find out more

The south Devon coast is also known as an Important Invertebrate Area by Buglife.

Buglife has information about the Devon red-legged robberfly on its website. 

South Devon National Landscape | South Devon National Landscape 

Information on the Heritage Lottery funded project focused on this stretch of coast Life on the Edge – Buglife projects 

The Open University Geological Society has information about the unique geology along this stretch of coast The Start Complex around Prawle Point in South Devon 

The Spider and Harvestman Recording Scheme website has information on all spiders.  

The Bees, Wasps & Ants Recording Society website has information on all bees, ants and wasps.  

The British Arachnological Society website has facts on all spiders and other arachnids.  

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