Saturday, 23 June 2018

White-legged Damselfly

The pond at Piltdown

We ventured north of the district yesterday in search of the White-legged Damselfly (Platycnemis pennipes). These elegant, feather-legged little damsels like to bask on abundant floating vegetation and the pond at Piltdown, which has caught my attention while driving past, looked a promising site.
My reason for hunting ‘featherlegs’ is to contribute to a survey that’s been organised by the British Dragonfly Society: the White-legged Damselfly Investigation. The point is to learn more about this species and add to our limited understanding of it. There are increasing concerns that this dainty little insect is in decline in Britain. More information about the survey can be found here.

The very first damsel I focused my binoculars on was a White-legged Damelfly, a male on an iris leaf manoeuvring its abdomen in the fashion of an ovipositing female. On closer inspection it was stuck to some spider silk. Once freed it stood on my finger for a few moments before gently alighting half a metre to another iris, where we both lingered for a little while.

The pond didn’t disappoint; it was alive with seven damselfly species, basking on what seemed every blade and leaf of vegetation. Black-tailed Skimmers patrolled the banksides while teeming Swifts screeched above them. Two hours later I had seen eight damselfly and dragonfly species, along with a few other species of interest.

Rutpela maculata long-horn beetle

Species seen:

Odonata (eight species) 
 Banded Demoiselle (Calopteryx splendens)  2
White-legged Damselfly (Platycnemis pennipes)  2
Large Red Damselfly (Pyrrhosoma nymphula)  2
Blue-tailed Damselfly (Ischnura elegans)  29
Common Blue Damselfly (Enallagma cyathigerum)  5
Azure Damselfly (Coenagrion puella)  120
Red-eyed Damselfly (Erythromma najas)  5
Black-tailed Skimmer (Orthetrum cancellatum)  12

Lepidoptera (eight species)
Nut Leaf Blister Moth (Phyllonorycter coryli)  - mines on hazel leaves
Large Skipper (Ochlodes sylvanus)  3
Large White (Pieris brassicae)  1
Small White (Pieris rapae)  4
Green-veined White (Pieris napi)  2
Ringlet (Aphantopus hyperantus)  1
Meadow Brown (Maniola jurtina)  1
Comma (Polygonia c-album)  1

Coleoptera (one species)
Yellow and black Longhorn Beetle (Rutpela maculata) 2

White-legged Damselfly (Platycnemis pennipes)

Blue-tailed Damselfly (Ischnura elegans)

Friday, 13 October 2017

The end of the survey season at Newhaven's Castle Hill Local Nature Reserve

The dodgy weather during the first half of the week meant that I didn't get out until Thursday lunchtime. There was a decidedly autumnal feel (if it's not stating the obvious) and the sun hadn't burnt off the previous night's dew despite a sunny morning, such is its lack of strength in late October. Butterfly activity was low and I saw only twenty in total (six species), as follows:

Large White 1
Small White 3
Speckled Wood 7
Red Admiral 6
Painted Lady 1
Comma 2

This week was the final week of the official survey season, but Dave usually continues surveying until butterfly activity settles down for the winter. The butterflies are now mostly confined to the sheltered footpaths and areas with ivy still in blossom, but there are still opportunities to find them when it's not too chilly. Small Tortoiseshells and Peacocks have probably already flown into the Fort's tunnels to overwinter and my next surveying activity will be in mid-December when we make our first winter count in the tunnels. Until then it's back over to Dave and the Gang to see what's still active above ground. At least it will take longer for the ice cream to melt!
My attention will now focus on collating all the data we've collected this year and compare it with previous years. This will take some time but I am hoping to have the year's results ready to share at the December meeting.

I am also continuing work this winter on the nature reserve's 'Super List' as we approach the fifty year anniversary in 2021 of the first formal records made along the Newhaven clifftops and slumps. The list will eventually include every known record ever made at the site and there are some impressive recorder names already on the list, as well as some impressive species, not least the Mediterranean Oil Beetle (Meloe mediterraneus) which was discovered earlier this year. The list will be a valuable resource when it is completed (hopefully by winter 2018/19) and I hope it will inspire additional recording effort.

Thursday, 31 August 2017

Late August at Castle Hill LNR, Newhaven

I did the week 22 walk on Sunday 27th in what for Castle Hill was uncharacteristically calm weather. This made for good butterfly conditions along the clifftops and there was much activity for the time of year. I counted 366 butterflies and moths of 13 and 12 species respectively. This is not a bad haul, but is lower than the same week in the previous two years, when over 400 were counted. Week 22 has usually been the final week of abundant activity at Castle Hill, so we might find a drop in numbers next week.
Straw Conch (Cochylimorpha straminea)

I don't want to get too carried away with excitement, but there has been something special happening this year for the Small Heath butterfly. I have been recording more than 130 at Rookery Hill in Bishopstone on some days recently and, on Sunday, I recorded nearly as many Small Heaths in one day (96) as we counted in the six years between 2011 and 2016 (113 in total during this period). Both Dave Harris and the County Lepidoptera Recorder, Colin Pratt, have commented that this butterfly appears to have recovered to its pre-decline 1970 population level. Let's hope it is sustained in the coming years. Isn't it wonderful to have a success story for once when considering the plight of so many other species?!!

Amongst the moths, I recorded our first Straw Conch (Cochylimorpha straminea) in seven years at the reserve and saw more of the Common Grass Veneer (Agriphila tristella) than we've ever counted before in a single day. This moth is having a good season and has been seen in good numbers everywhere recently. This distinctive moth, which has a pale streak running along the length of its wing, flies out of the grass ahead of you when you walk along country paths in the late summer and lands a few metres ahead, parallel with a grass stem.

Purple Loosestrife
Other items of interest include some purple loosestrife found growing by the 'old pond' (Dave tells me this is a new plant species for the reserve list) and some birds including a female Wheatear, two ravens and a sparrowhawk all along the clifftop.

Amongst the photos I've included is a shot of a hazy Seaford Bay. This haze is the infamous cloud that affected people later in the day on the beaches between Birling Gap and Hastings. When the weather is settled and sunny, an accumulation of pollutants such as oxides of nitrogen and other volatile compounds react with UV in strong sunlight to create ozone at low levels. This 'photochemical smog' causes severe irritation to eyes, nose and throat upon exposure. Air quality data measured at the Lullington Heath station on the same day showed a large spike in ozone levels. Thankfully those people at Newhaven's West Beach were not so affected.

Hopefully there will be no such hazards for Dave during week 23.
Low-level ozone at Seaford Head?

Late summer colour in the Wassail Glade at Castle Hill LNR
 25 species (13 butterfly, 12 moth); 366 individuals.

Large White (Pieris brassicae) 21
Small White (Pieris rapae) 68
Green-veined White (Pieris napi) 1
Clouded Yellow (Colias croceus) 2
Speckled Wood (Pararge aegeria) 19
Small Heath (Coenonympha pamphilus) 96 – highest numbers ever seen at CHLNR
Meadow Brown (Maniola jurtina) 65
Gatekeeper (Pyronia tithonus) 1
Red Admiral (Vanessa atalanta) 6
Painted Lady (Vanessa cardui) 1
Small Copper (Lycaena phlaeas) 4
Holly Blue (Celastrina argiolus) 2
Common Blue (Polyommatus icarus) 25

Golden Pigmy (Stigmella aurella) leaf-mines on bramble
Bordered Carl (Coptotriche marginea) leaf-mines on bramble
Apple Leaf Miner (Lyonetia clerkella) leaf-mines on apple and cherry
Common Nettle-tap (Anthophila fabriciana) 3
Straw Conch (Cochylimorpha straminea) 2 – first site record since 2010
Straw-barred Pearl (Pyrausta despicata) 10
Rusty-dot Pearl (Udea ferrugalis) 1
Rush Veneer (Nomophila noctuella) 3
Common Grass-veneer (Agriphila tristella) 32 – best numbers ever seen at CHLNR
Common Carpet (Epirrhoe alternata) 1
Vapourer (Orgyia antiqua) 1
Silver Y  (Autographa gamma) 2

Thursday, 17 August 2017

Mid-August at Castle Hill LNR, Newhaven

Week 20 of the Castle Hill LNR butterfly survey season

Rampion off-shore windfarm in progress - as seen from the Castle Hill LNR clifftop
Seed-spangled orb web
I did my transect walk on Sunday in better weather conditions than I've had recently. We're at week 20 of 28 already. I've added below a list of what I saw. Most of the flowers are now past their peak, but there is still a mass of late-summer colour. The willowherb was casting immeasurable numbers of seeds into the air and all the spider webs were spangled with them.
There were 25 species of butterfly and moth and a total of 438 individuals, which I thought was pretty good considering the time of year. I was particularly pleased to see 27 Small Heaths; it has never been a common butterfly at Castle Hill LNR and has significantly declined in the UK over the past few decades, mainly because of the loss of habitat as grazing land has been 'improved' for livestock. It is a butterfly that likes fine grasses on dry soils and Castle Hill offers some good potential habitat, particularly along the clifftops.  Annual totals since 2011 have been 3, 7, 12, 23,31 and 37, so to have seen 27 in one day, mostly along the clifftop, is great news. It has been having a good year generally and I have been counting up to 80 on some days in a meadow near The Rookery at Bishopstone.

Small Whites were seen in good numbers; it was strange to have seen 60 and not a single Large or Green-veined White to go along with them - I wonder what the odds are of that?! Clouded Yellows are beginning to make an appearance and Holly Blue numbers were good along the northern path.
Volucella pellucens - the Pied Hoverfly
Amongst the other stuff seen were quite a few Volucella hoverflies. V. zonaria and pellucens are among the most spectacular of the 7000 species of British fly. A female Wheatear was seen on the clifftop, indicating that the autumn migration is upon us. Another year if flying by!

Butterflies (13 species)

Small White
Pieris rapae
Clouded Yellow
Colias croceus
Speckled Wood
Pararge aegeria
Small Heath
Coenonympha pamphilus
Meadow Brown
Maniola jurtina
Pyronia tithonus
Red Admiral
Vanessa atalanta
Painted Lady
Vanessa cardui
Inachis io
Small Tortoiseshell
Aglais urticae
Polygonia c-album
Holly Blue
Celastrina argiolus
Common Blue
Polyommatus icarus
Moths (12 species)

Bordered Carl
Coptotriche marginea
3 (mines)
Common Nettle-tap
Anthophila fabriciana
Ox-tongue Conch
Cochylis molliculana
Common Marble
Celypha lacunana
Grey Gorse Piercer
Cydia ulicetana
Six-spot Burnet
Zygaena filipendulae
Straw-barred Pearl
Pyrausta despicata
Small Purple & Gold
Pyrausta aurata
Common Purple & Gold
Pyrausta purpuralis
Rush Veneer
Nomophila noctuella
Straw Grass-veneer
Agriphila straminella
Silver Y
Autographa gamma
Other stuff

Common/Viviparous Lizard
Lacerta vivipara
Falco tinnunculus
Accipiter nisus
Wheatear (female)
Oenanthe oenanthe
Southern Hawker
Aeshna cyanea
Pied Hoverfly
Volucella pellucens
Hornet Hoverfly
Volucella zonaria