Tag Archives: philanthus triangulum

Cogden beach in west dorset – a late summer’s day visit

[This article appeared in the October edition of the Marshwood Vale Magazine and describes a visit I made to Cogden Beach on July 30th this year. ]

I’ve driven along the coast road eastwards from Burton Bradstock many times but the view as the road levels out at the top of the first hill never fails to lift my spirits.  That first glimpse of the sea.   Those coastal hills spread out ahead as they slope gently down to the water.  That vast shingle beach with its fringe of foam, stretching into the distance.  This time I was on my way to Cogden Beach, part of the larger Chesil Beach and one of my favourite west Dorset places where I can be outside in the air, close to the sea and surrounded by nature.

The road dipped down and I reached the car park above Cogden but I had never seen it this full.  Many people were taking advantage of the warm, sunny, late July day and I was lucky to find one of the last parking spaces.    The view from the car park across Chesil Beach was as familiar and fascinating as always.  The strip of pale brown shingle swept eastwards across my field of vision in a broad arc turning sharply towards Portland, its distinctive wedge shape held in a blue haze as if suspended above the water.  The sea was a uniform azure, a colour so intense in that day’s strong sun that I couldn’t stop looking. Towards Portland, though, the sun intervened, casting its light downwards across the sea, silvering the surface which shimmered in the breeze like crumpled aluminium foil. 

I left the car park and headed down hill towards the sea across the short grass that appeared to have been grazed recently, a pity as this had eliminated most of the flowers, and the insects.  Dark sloes and ripening blackberries showed in the path-side scrub, sure signs that the year was moving on.  Families passed me, some laden with colourful beach kit, others dressed for coastal walking.  Stands of intensely pink, great willowherb and sun-yellow fleabane grew in a damp area as the path approached the shingle.  A small flock of about 50 birds, probably starlings, surprised me by flying up from the scrub in a mini-murmuration.  They banked and wheeled, flying back and forth for a short time before settling back on the bushes where they chatted noisily to one another. 

I walked on to the shingle beach where, ahead of me, a small windbreak village had grown up. Some of the inhabitants were simply soaking up the sun, others were swimming or enjoying stand up paddleboards while some concentrated on their fishing.   Heat shimmered from the pea-sized pebbles but a light breeze kept the temperature pleasant.  Desultory waves made their way up the beach disturbing the shingle which retreated in a rush leaving some white water.

The wild garden of beach plants looking west

Towards the back of the shingle was the wild garden of beach plants that emerges afresh from the pebbles each spring and summer making this place so special.   I stopped to look at the sea kale that grows so profusely here.   Its thick, cabbage-like leaves were a glaucous green tinged with varying amounts of purple that seemed to come and go according to the angle of vision rather like the colours on a soap bubble.  Flowering season was long past but the memory lingered and each clump was adorned with a large fan of hundreds of spherical greenish yellow seeds    Among the clumps of sea kale were the roughly crimped leaves of yellow horned-poppy, displaying its distinctive papery yellow flowers alongside some of the very long, scimitar-like seeds pods.  The almost primeval vision created by these rare and unusual plants growing from the shingle was completed by clumps of burdock with its prickly green and purple hedgehog-like flowers.

Sea kale showing the glaucous leaves and the fan of greenish yellow seeds
Yellow horned-poppy

The coast path heads westwards along the back edge of this wild garden of beach plants and for the most part it is rough and stony.  In places, however, shallow holes have appeared exposing the sandy soil beneath.  Large black and yellow striped insects were moving about in some of these exposed holes.  Sometimes these insects would dig, rather like a dog with sand shooting out behind them.  Sometimes they encountered a small stone and lifted it away, secured between two legs.  These are beewolves (Philanthus triangulum), spectacular solitary wasps up to 17mm long that were once very rare in the UK but, since the 1980s, have expanded their range. 

I watched them for a short time before heading west on to the shingle.   I soon reached the area where there are low cliffs at the back of the beach composed of thickly packed firm sand, topped by rough grass and clumps of desiccated thrift.  These cliffs were punctuated by small holes, sometimes with a spill of sand emerging and here I found the same beewolves with their distinctive yellow and black markings. They were coming and going from the holes regularly and sometimes they would rest in a hole and look outwards. 

Male beewolf with distinctive facial markings
Female beewolf with prey

Beewolves have an interesting lifecycle.  The insects emerge from hibernation in the summer and the females begin to dig nest burrows up to a metre long in friable soil or sand with as many as 30 side burrows that act as brood chambers.   At about the same time the females choose males for mating.   Each female then hunts honeybees, paralysing them with her sting and bringing them back to place in each brood chamber where she also lays a single egg. This matures into a larva that feeds from the honeybees, hibernates over winter and emerges the following summer as a new beewolf.   Although this may seem slightly gruesome, the number of beewolves in the UK is still low and does not impact significantly on the honeybee community.  Also, adult beewolves are herbivores feeding only on pollen and nectar collected from flowers so acting as important pollinators.

I was able to witness some of this activity including a female returning with prey held beneath her to be mobbed by other beewolves and common wasps trying to steal her cargo.  For most of the time, however, these insects get on with their lives quietly, unseen by visitors.  I did notice one couple who chose a pleasant spot on the top of the low cliffs to sit and admire the view, only to find they were surrounded by beewolves.  The couple moved but in fact these beautiful insects are not predatory and pose no threat to humans.

By mid-afternoon, it was time for me to leave.  I took in one last view along the coast and headed back up the hill knowing that I would return in another season.

Cogden Beach is at the western end of Chesil Beach and can be accessed either via the South West Coast Path or from the National Trust Car Park on the coast road (B3157) between Burton Bradstock and Abbotsbury. OS grid reference SY 50401 88083, GPS coordinates 50.690271, -2.7035263.

An oasis of calm, a mosaic of environments

Towards the end of July, I visited the Maer, a nature reserve situated at the eastern end of the promenade in Exmouth, a seaside town in the south west of the UK.  With its sand dunes and sandy grassland, the Maer is a remnant of a much larger dune system that once stretched down to the beach. Nowadays, it provides an oasis of calm close to the busy sea front as well as a habitat for special plants and insects.

sea holly growing on the sandy ridge

A slight mist softened the long views as I walked eastwards along Exmouth sea front.  Some warmth penetrated the cloud and a few people were already enjoying the beach on this late summer morning.  The sandy tip of Dawlish Warren lay tantalisingly close across the water and further on, the Ness at Shaldon lurked in the mist like a gigantic wedge of cheese.  The commercial area with its big wheel, pubs and cafes was busy but eventually I reached a quieter part where sand and scrub tumbled downwards at the side of the beach road.  This is the edge of the Maer, a local nature reserve and one of Exmouth’s hidden gems. Superficially, the Maer is a large grassy, sandy space sandwiched between the beach road and Exmouth Cricket Club but it conceals a mosaic of different environments with unusual flora and fauna.

A substantial sandy dune ridge forms the southern border of the Maer giving views across the reserve on one side and towards the beach on the other.  Marram grass grows thickly giving the sand stability but there are also areas of bare sand and areas of scrub, reminders of the dune system that must have occupied this area before the beach road was built.  Restharrow with its pink and white pea-type flowers and a few residual yellow evening primrose provided some colour but it was the sea holly that surprised.   This is an unusual and unexpected plant that grows extensively along the first part of the ridge.  Its spiky greenish-grey leaves with white margins and veins and its powder blue flowers light up the sand as though someone had spilt pale paint.  Sea holly flourishes in these arid conditions by having leaves covered in a waxy cuticle to help retain water and through its deep roots. Although sea holly has some visual resemblance to our Christmas greenery, it is a relative of the carrot; in the past it was employed as an aphrodisiac.

Several large insects with bold black and yellow markings crawled about the bright blue sea holly flowers collecting nectar.  These are beewolves, some of our most spectacular solitary wasps, that nest in sandy places and specialise in catching honeybees.  Both male and female beewolves were feeding that day but it is the larger female (up to about 2cm long) that catches and paralyses honeybees and may be seen flying back to the nest carrying a quiescent honeybee beneath her.  She digs a nest tunnel in sandy soil up to a metre long with multiple terminal branches where she lays eggs and provides honeybees as food for the developing larvae.  These once rare insects have expanded their UK range since the 1980s, possibly in response to climate change and I saw them in several places on the reserve notably on a stand of mauve thistles. They are not aggressive towards humans.

Further along the ridge, before it is colonised by brambles, scrub and low trees, I found a large clump of an unruly scrambling plant covered in pea-type flowers of an impressive reddish-pink colour.  This is broad-leaved everlasting pea, a perennial relative of our annual sweet pea, growing through the grasses on the Maer ridge holding on via thin tendrils.  A chunky dark bee was feeding from the flowers, apparently undeterred by their jerky movements in the breeze. This was a leafcutter bee, most likely the Coast Leafcutter Bee that favours sandy habitats near the sea.  They nest in burrows in vegetated sand lined with pieces of leaf cut from trees and plants.    Later, when the sun came out, I saw several of these bees chasing one another around the bright pink flowers like children in a playground.

The large central part of the reserve was coated with golden brown grass criss-crossed with paths for walkers and looking very dry, a reflection of the recent lack of rain.  Within the grass were mats of restharrow and many of the yellow dandelion-like flowers of catsear.  One area resembled a lunar landscape with many small craters where the surface had been dug out exposing the sand.  Solitary wasps and small leafcutter bees had happily nested here.

Tall clumps of ragwort with bright yellow daisy-like flowers and deeply lobed green leaves were dotted around the central area. This plant provides valuable habitat and food for invertebrates and I found one clump that had been appropriated by black caterpillars with prominent yellow bands.  They were moving about, eating the leaves of the ragwort, voraciously consuming the greenery and destroying the upper parts of the plant.  These are caterpillars of the cinnabar moth and as they feed, they assimilate some of the toxic alkaloids contained in ragwort, rendering themselves unpalatable to birds and other predators.  It is said that their yellow stripes act as a warning to birds.   Once fed and mature, the caterpillars dig themselves into the ground to spend 12 months or so as pupae before emerging as beautiful day-flying red and black moths.  The adult moths live for a few weeks, feeding on nectar before mating and laying eggs on the ragwort leaves.  The eggs grow into caterpillars and the cycle starts all over again.   The cinnabar moth is entirely dependent on ragwort for its survival.

Towards the western end of the reserve, I found a large colony of flowering plants, perhaps suggesting damper conditions.  Clumps of common mallow up to a metre tall dominated with their trumpet flowers composed of five deep pink petals each with purple stripes.  At the centre of each flower was a mass of grey pollen-covered stamens emanating from a single stalk like a miniature bunch of flowers.  Near the mallow, large areas were covered by a sprawling, scrambling plant richly covered with pea-like flowers above many small, spear-shaped, mid green leaves.  Flower colours varied from very pale to light blue, mauve and deep purple with some plants having several of these colour variants.  One plant even had bright yellow flowers.  This is Sand Lucerne, a fertile hybrid of lucerne and sickle medic, naturalised in East Anglia, where its two parents grow together, but now transplanted elsewhere.

There’s so much to see at the Maer and I could easily have spent several more hours looking about.  But I had a train to catch so I headed back along the promenade and across the town towards the station.

This article appeared in the October edition of the Marshwood Vale Magazine.

The picture at the head of this article shows the sandy ridge just above the seafront in Exmouth and the clump of broad-leaved everlasting pea.

 

beewolf on sea holly
male beewolf on sea holly

 

Female beewolf on thistle
female beewolf on thistle

 

Broad-leaved everlasting pea with leafcutter bee
leafcutter bee on broad-leaved everlasting pea

 

cinnabar moth caterpillars on ragwort
cinnabar moth caterpillars on ragwort

 

common mallow
common mallow

 

Sand Lucerne
sand lucerne