COAST - PURBECK: GODLINGSTON HEATH

Agglestone is one of the high points on Godlingston Heath Nesting site for Purbeck Mason Wasps (Pseudepipona herrichii) Nectaring occurs principally on Bell Heather
Female Purbeck Mason Wasp carrying a caterpillar into her burrow Eumenes coarctatus female gathering clay for the construction of pots on heather or gorse Male Eumenes coarctatus showing the distinctive shape of the abdomen
Anthophora bimaculata is a very noisy flier Anthophora bimaculata, with stunning green eyes, hanging on like grim death on a windy day A Downy Emerald (Cordulia aenea) male defending his territory
Male Keeled Skimmer (Orthetrum coerulscens) Female Ruddy Darter (Sympetrum sanguineum) Round-leaved Sundew (Drosera rotundifolia)

The sea is visible from much of Godlingston Heath, especially from one of the highest points at Agglestone, but the habitat is strict heathland rather than duneland.

Without much doubt the rarest creature on the premises is the handsome but endangered Purbeck Mason Wasp (Pseudepipona herrichii, 11mm), provisionally a Red Data Book 1 species.

Although capable of breeding gregariously at various locations solely in this part of Dorset in late June and July, the wasp's reliance on a particular soil type and particular prey make its continued survival problematical even with appropriate conservation management.

One of the nesting sites is shown above, involving clay with heather, a wet area out of shot on the right to help the wasp seal the underground burrow, and good supplies of the only prey species, larvae of the moth Acleris hyemana, which feeds on Bell Heather (Erica cinerea).

Rather like the Silver-studded Blue butterfly (Plebeius argus), Acleris hyemana is an early to mid-succession species in its habitat, ideally suited by young heather. It follows that the Purbeck Mason Wasp is also an early to mid-succession species, with the additional drawback of needing clay,Dodder (Cuscuta epithymum) parasitises mostly heather which is not a common soil on coastal lowland heathland.

The wasp has maintained reasonable levels through the last 20 years, but the peculiar habitat requirements, plus the need for what is a labour-intensive management method of cutting heather back to encourage regeneration, suggests it is never likely to be completely safe.

Just as the prey feeds on Bell Heather, so the Purbeck Mason Wasp nectars almost entirely on the same plant. With tongues not much more than a millimetre in length, the wasps have to cut into the corolla to get what they want. The accompanying picture shows one engaged in this activity on Bell Heather, with evidence on the rest of the flower head that the bloom had been systematically 'robbed'.

The Potter Wasp (Eumenes coarctatus, 11mm) is nothing like so rare as Pseudepipona herrichii, but it is scarce, found mostly on heathland in Dorset, Hampshire and Surrey. The female builds pots of clay mainly on heather or gorse to hold her eggs and their food. Both sexes have a very distinctive shape to the abdomen that separates them from any other British wasp.

There is no shortage of bees on the heath. Anthophora bimaculata (9mm), which nests in exposed soil, sometimes in large numbers, has distinctive green eyes. Like the rest of the Anthophora tribe it hovers but it makes a lot more noise doing so, with the hum set up by a group travelling quite a way.

Acidic mires and watercourses provide a refuge for various types of dragonfly and damselfly. The Keeled Skimmer (Orthetrum coerulscens, length 60mm) is found principally in the West Country, Wales and western Scotland, but it is also locally common in Dorset, Hampshire, Surrey and Sussex.

The Ruddy Darter (Sympetrum sanguineum, lengthCotton-grass (Eriophorum angustifolium) is rarely motionless 45mm) is not so closely linked to acidic conditions as the Keeled Skimmer, and has its stronghold in the area of England covered by this website. Unlike the Keeled Skimmer, which is seen from June to August, the Ruddy Darter may be seen right up to October.

The Downy Emerald (Cordulia aenea, length 60mm) is an active, fast-flying species with remarkably bright eyes. They are suited by ponds in deciduous woodland where the male patrols aggressively.

Downy Emeralds are seen in June and July in their strongholds of Dorset, Hampshire, Surrey and Sussex. They are commoner than the related Brilliant Emerald (Somatochlora metallica), which is much more closely associated with acidic soils but is not found in Dorset.

Godlingston has the usual range of heathland plants, including the wraith-like Common Cotton-grass (Eriophorum angustifolium), which seems to move even when there is no discernible wind. All three native carnivorous sundews are found there, including Round-leaved Sundew (Drosera rotundifolia), while the rootless parasite Dodder (Cuscuta epithymum) plies its trade commonly on the abundant heather or the gorse.

Images © Jeremy Early. All rights reserved.

In 2013 I published My Side of the Fence - the Natural History of a Surrey Garden. Details may be found, and orders placed, via this hyperlink My Side of the Fence. In November 2015 Surrey Wildlife Trust published the atlas Soldierflies, their allies and Conopidae of Surrey, jointly written by David Baldock and me. Details are on this web page: Atlas.