24 June 2014

Moth trapping on Dartmoor

Just back from a week staying with our friends Kevin and Donna Cox at their 'pad' Brook Manor, in the Mardle Valley on the east side of Dartmoor. We made good use of Kevin's Robinson MV moth trap and recorded a huge diversity of species over four trapping sessions. White Ermine Spilosoma lubricipeda was the most abundant species, but we also recorded a wide diversity of species, a few regional specialities as well as a few migrants. Here's a selection of the species trapped during the week.

Double Line Mythimna turca, 10 June - largely confined to south-west England and south Wales

Lobster Moth Stauropus fagi, 10 June

Scorched Wing Plagodis dolabraria, 10 June

Buff-tip Phalera bucephala on a broken Silver Birch twig - amazing camouflage!

Mating Buff-tips Phalera bucephala, 9 June

Elephant Hawkmoth Deilephila elpenor, 9 June

Small Elephant Hawkmoth Deilephila porcellus, 9 June

Pebble Prominent Notodonta ziczac, 9 June

Green Silver-lines Pseudoips prasinana, 9 June

Small Angle Shades Euplexia lucipara, 9 June

Pale Tussock Calliteara pudibunda, 9 June

Barred Umber Plagodis pulveraria, 9 June

Brown Rustic Rusina ferruginea, 9 June - note the rather worn look, even though it is fresh

Peppered Moth Biston betularia, 9 June

Beautiful Golden Y Autographa pulchrina, 9 June

Peach Blossom Thyatira batis, 10 June

True Lover's Knot Lycophotia porphyrea, 13 June

Foxglove Pug Eupithecia pulchellata, 10 June

Brindled Plume Amblyptilia punctidactyla, 10 June

13 June 2014

Rare ground beetles on Dartmoor: 13 June

Rachel and I met up with John Walters again this evening, this time to visit Dendles Wood - a patch of ancient oak pasture woodland situated on the southern edge of Dartmoor, to search for Britain's largest ground beetle - the Blue Ground Beetle Carabus intricatus. Blue Ground Beetles are nocturnal, spending the day in the soil and emerging after dark to climb the moss-covered oaks to hunt slugs. Spring to early summer is the best time to see them, when the adults are most active searching for mates1.

Blue Ground Beetle is an Endangered Red Data Book species now restricted to just seven sites in south-west England and a single site in Wales, with southern Dartmoor being the species stronghold. They have only ever been recorded at 15 sites in Britain, and have been considered extinct more than once2.

A couple of hours lamping moss covered oaks produced 2 Blue Ground Beetles, 1 Lesser Searcher Calosoma inquisitor devouring a caterpillar - a behaviour very rarely witnessed in the wild as this rare beetle tends to feed high in the canopy, 3 Ridged Violet Ground Beetles Carabus problematicus, and a single Moorland Ground Beetle Carabus arvensis. Also, another previously captured Lesser Searcher was released by John.

Tonight was quite dry so slugs were thin on the ground, apart from a single Leopard Slug Limax maximus. Also noted were a Nalassus laevioctostriatus - a Darkling (Tenebrionid) beetle, and a colony of Tree lungwort Lobaria pulmonaria.

Blue Ground Beetle Carabus intricatus, Dendles Wood

Lesser Searcher Calosoma inquisitor, feasting on a caterpillar (that was still alive when we first found it), Dendles Wood

Ridged Violet Ground Beetle Carabus problematicus, Dendles Wood

Moorland Ground Beetle Carabus arvensis, Dendles Wood - more commonly found on the open moor

Tree lungwort Lobaria pulmonaria - an epiphytic Lobariaceae lichen indicative of ancient forest, widely distributed across the
northern hemisphere and even recorded in tropical rainforest in Costa Rica (more here).

A huge thanks to John Walters for a fascinating and very memorable evening. I learn't a lot about these amazing insects and their ecology, and being eaten alive by midges was a small price to pay! For more information on the Blue Ground Beetle see John's website (where you can download some identification excellent guides) and the references below.

References

1 Baldock, N. & Walters, J. (2008) The Wildlife of Dartmoor. Newton Abbot: Wotton Printers.
2 Boyce, D. & Walters, J. (2001) The conservation of the Blue Ground Beetle in south-west England. British Wildlife 13: 101-108.

Crab Spider (Misumena vatia): 13 June 2014

Found a superb female Crab Spider Misumena vatia in the wet meadow at Brook Manor and spent some time watching and photographing it.

These spiders specialise in hunting pollinating insects that visit white coloured flowers. But rather than using their white colouration as camouflage to hide them from their prey, the spiders are actually more visible to insects than they are to humans, being clearly visible in ultraviolet. Many plants use ultraviolet markings to guide insects to nectar, so insects are possibly attracted to the ultraviolet colour of the spiders. The white colouraton of the spider that we can see is probably to hide them from predators.

Female Crab Spider Misumena vatia, Brook Manor, Devon, 13 June 2014

Crab Spiders do not spin webs but are ambush predators, grabbing and injecting venom into prey through their fangs

Crab Spiders are so called after their habit of holding the first pair of legs apart

Superbly camouflaged, females are very variable in colour and pattern and able to change their colour to match the colour of the flower
they are hunting from (usually white or yellow)

More information on this beautiful spider here. Also, compare this widespread British, European and North American species to the much meaner looking Brazilian Crab Spider Epicadus heterogaster I photographed at REGUA in 2013.

12 June 2014

Prawle Point, Devon: 12 June

Spent the day at Prawle Point - one of my favourite headlands in south-west England. Things were quiet bird-wise, with 1 Manx Shearwater E, 1 Yellowhammer and 4 Cirl Buntings being the most noteworthy, but with reports of migrant butterflies and moths arriving in Britain over the last few days we concentrated on lepidoptera today.

A circular walk taking in Langerstone Point and Signalhouse Point produced a single worn Painted Lady Vanessa cardui, a Small Pearl-bordered Fritillary Boloria selene, 1 Dark Green Fritillary Argynnis aglaja, 5 Large Skipper Ochlodes sylvanus, 3 Meadow Brown Maniola jurtina, 1 Large White Pieris brassicae, 2 Red Admiral Vanessa atalanta, 4 Speckled Wood Pararge aegeria and 3 Six-spot Burnets Zygaena filipendulae.

A rather worn Painted Lady Vanessa cardui - the only migrant butterfly we found today

11 June 2014

Dart Valley Nature Reserve and Vogwell, Devon: 11 June

Rachel and I spent much of the day walking the pipeline trail through ancient sessile oak woodland along the Dart Valley near Bench Tor. Highlights were 4 Wood Warbler (including a ringed male), 4 (2m, 2f) Common Redstart (including a pair bringing food to a nest hole), 2 (1m, 1f) Pied Flycatcher, 1 Spotted Flycatcher, 2 Eurasian Treecreeper, 3 Siskin, 1H Cuckoo and several Speckled Woods Pararge aegeria. On the open moor around Bench Tor 1 Tree Pipit, 2 (1m, 1f) Stonechat, a female Clouded Buff Diacrisia sannio and 2 Small Heath Coenonympha pamphilus were logged.

Wood Warbler, Dart Valley Nature Reserve

Wood Warbler, Dart Valley Nature Reserve

Ringed male Wood Warbler, Dart Valley Nature Reserve

A late afternoon visit to a private hay meadow at Vogwell with Kevin Cox and John Walters failed to locate any Narrow-bordered Bee Hawk-moths Hemaris tityus in cool heavily overcast conditions, but 4 docile Marsh Fritillary Euphydryas aurinia, several Chimney Sweepers Odezia atrata and huge numbers of Heath Spotted Orchids Dactylorhiza maculata more than made up for it. A fantastic site; I could spend days exploring this meadow.

Marsh Fritillary Euphydryas aurinia, Vogwell

A detour to Bovey Heathland Local Nature Reserve this evening on the way back from Vogwell produced excellent views of a male European Nightjar roosting in a tree and a single Bee Orchid Ophrys apifera.

3 June 2014

A few notables at home

A few notables at home over the last few days. On 27 May: 1 Cabbage Moth Mamestra brassicae, 1 Silver Y Autographa gamma and 1 Bright-line Brown-eye Lacanobia oleracea were all new for the year, on 1 June: 1 Large Tabby Aglossa pinguinalis, 1 Mint Moth Pyrausta aurata and 1 male Banded Demoiselle Calopteryx splendens are all garden ticks, as was a Common Buzzard very low over being mobbed by Carrion Crows, and this evening a Garden Carpet Xanthorhoe fluctuata.

Large Tabby Aglossa pinguinalis - the first for the garden

Large Tabby Aglossa pinguinalis