Monday, 20 February 2017

Frog on the Move

The mild spell over this last week has seen me spending several days working in the wood. Most of the coppicing for this winter is now done but the task of thinning, stacking and rhododendron clearance carries on. There is always time for a relaxing walk through the trees when the muscles are getting a bit tired.
At the weekend, I came across a Common Frog (Rana temporaria) moving across the woodland floor and clearly on a mission to get to its breeding pond.
Common Frog (Rana temporaria)
I also found this interesting looking fungus. I think that it is probably an Oak Mazegill (Daedalea quercina) although I'm pretty certain that it was growing on a dead stem of sweet chestnut...I must go back and check!
Oak Mazegill (Daedalea quercina)

Earlier in the week, Carol found the shed antler of a Fallow Deer laying on the ground near one of their regular rutting sites.
Fallow Deer (Dama dama) (shed antler) 

I saw my first butterfly of the year back on 16th January in the form of a Red Admiral (Vanessa atalanta) flying around the car park at Birling Gap. I've yet to see any others but I did come across a very early queen Common Wasp (Vespula vulgaris) flying across a local Wealden meadow.
Common Wasp (Vespula vulgaris) (queen emerged from hibernation) 


Friday, 27 January 2017

Variation in Butterflies

Variation in butterflies is an interesting subject within the study of lepidoptera and there are a number of reasons for its occurrence. I am no scientist but broadly speaking, variation can occur as a result of the geographical isolation of populations which can lead to different sub-species and even new species evolving. Variation between the sexes (sexual dimorphism) and variation between different broods (seasonal dimorphism) occurs in many species. Variation (or aberrations) can also occur within a species as a result of genetic mutation or environmental influences during critical stages of the life cycle.   
I have seen numerous variations over the years and here is a selection of photographs.
Although the occurrence of some variants can be manipulated through captive breeding, the following examples were found and photographed in the wild.
Clouded Yellow (Colias croceus) (female)
The standard form.
Clouded Yellow (C.croceus) (female, form helice)
This pale form only occurs in the female of the species and can account for 10% of females.

Small Copper (Lycaena phlaeas) (female, form caeruleopunctata)
A regular form which displays a line of blue submarginal spots on the hindwings.

Small Copper (L.phlaeas) (male, ab. schmidtii)
This aberration is a genetic mutation caused by a recessive gene.

Common Blue (Polyommatus icarus) (male)
This species is sexually dimorphic.

Common Blue (P.icarus) (female)

Common Blue (P.icarus) (female, ab. albocincta)
Common Blue (P.icarus) (female, ab. supracaerulea)

Chalkhill Blue (Lysandra coridon) (male, ab. caeca)
All sub-marginal spotting is absent.

Chalkhill Blue (L.coridon) (female, ab. postobsoleta)
The female of this mating pair is showing much reduced sub-marginal spotting on the hindwing. 

Duke of Burgundy (Hamearis lucina) (female)
Not strictly regarded as an aberration, this specimen is displaying a pigment deformity in one wing.

White Admiral (Limenitis camilla) (female)

White Admiral (L.camilla) (ab. obliterae)
The reduced wing markings are caused by low temperatures during the pupal stage of the life cycle.

Small Tortoiseshell (Aglais urticae)

Small Tortoiseshell (A.urticae) (a transitional form of ab. semi-ichnusoides)
This aberration is caused by high temperatures during the pupal stage of the life cycle.

Comma (Polygonia c-album)

Comma (P.c-album) (ab. obscura)
The markings on the hind wings have become blotched and the borders are indistinct.

Wall (Lasiommata megera) (male)

Wall (L.megera) (male, ab. fascia)

Gatekeeper (Pyronia tithonus) (female)
Gatekeeper (P.tithonus) (female, ab. anticrasipuncta)
Many aberrations take the form of enlarged or reduced eye-spots.

Meadow Brown (Maniola jurtina) (male, ab. pallidus)
The normally chocolate brown ground colour has been replaced by pale grey and is not to be confused with age related bleaching that often occurs in this species

Saturday, 14 January 2017

Encounters with Hawkmoths

Hawkmoths are members of the Sphingidae group and they are amongst our most impressive moths, being large and fast flying. They are regularly attracted to light and I have recorded most of our resident species in my wealden garden over the years as well as two regular migrant species. Most Hawkmoth larvae are easily recognised by their large size and tail horns.
All photographs have been taken in my garden unless otherwise stated.

Convolvulus Hawkmoth (Agrius convolvuli) (female)
This is a scarce migrant from the European mainland but can be quite numerous in good migration years.
Privet Hawkmoth (Sphinx ligustri)

Privet Hawkmoth (S.ligustri) (larva on ash)
This specimen was found on the South Downs in East Sussex.

Pine Hawkmoth (Hyloicus pinastri)

Lime Hawkmoth (Mimas tiliae)

Lime Hawkmoth (M.tiliae) (larva found wandering)

Eyed Hawkmoth (Smerinthus ocellata)

Eyed Hawkmoth (S.ocellata) (larva found wandering)

Poplar Hawkmoth (Laothoe populi)

Poplar Hawkmoth (L.populi) (larva on sallow)
This specimen was found on the South Downs in East Sussex.

Hummingbird Hawkmoth (Macroglossum stellatarum)
This is a day-flying migrant from the European mainland and can be common in good migration years.

Hummingbird Hawkmoth (M.stellatarum)
In flight.
Elephant Hawkmoth (Deilephila elpenor)

Elephant Hawkmoth (D.elpenor) (larva on greater willowherb)
This specimen was found near Arlington in East Sussex but I occasionally find them in my garden.

Small Elephant Hawkmoth (Deilephila porcellus)
In Sussex, this species is predominantly found in downland habitats. I have recorded it only once in my garden. These two specimens were attracted to light in a Seaford garden.

Small Elephant Hawkmoth (D.porcellus)

Thursday, 12 January 2017

Winter Pursuits

Winter is a quiet time for the amateur entomologist but it is a good time of year to search for eggs of the Brown Hairstreak (Thecla betulae). The adult butterfly can be rather elusive during its flight season but if you know where to look, its eggs can be much easier to find. This species is a late season emergent and it is the eggs that see out the winter months on blackthorn, its foodplant. The eggs are usually laid singly (but sometimes two or three in a group), generally in the fork of a branch, near where the current and previous year's growth meet.
Brown Hairstreak (Thecla betulae) (ova on blackthorn)

When the winter sun is shining, then for me, there is no better place to go for a walk than on Ashdown Forest. I met up with Bob on Wednesday for a walk around one of our regular routes. I had never seen a Great Grey Shrike (Lanius excubitor) before, a scarce but regular winter visitor to UK shores. Whilst I could have seen one long before now, I just don't possess the "twitcher" gene and I have always been happy to wait for the moment when I would come across one when out for a walk. Well, that thrill happened for me yesterday when Bob spotted one sitting on top of a gorse bush. I managed to record the moment with this rather long distance shot.
Great Grey Shrike (Lanius excubitor)  


Thursday, 29 December 2016

Bird's-nest Orchid and Variation in Bee Orchid

I take many photographs during the course of a season. Trying to see different species of butterfly and dragonfly in their prime during their respective flight seasons can lead to a busy time for the amateur naturalist. Inevitably, some events are quickly overtaken by others and photographs get overlooked. Looking back at this time of year allows me to fill in some gaps.
Visiting Ashdown Forest back in May, I managed to observe a freshly emerging Bird's-nest Orchid (Neottia nidus-avis) over the course of three weeks. This strange orchid contains no chlorophyll and obtains its nutrients from fungi. It is generally found in the shade of long established beech trees.
Bird's-nest Orchid (Neottia nidus-avis)
On 17th May, the flower spike is just starting to emerge.
On 23rd May, one flower is starting to open.
On 2nd June, the plant is nearly in full flower.

The Bee Orchid (Ophrys apifera) has several named varieties, some of which can be quite numerous in some colonies. Var. chlorantha has whitish sepals and a greenish-yellow lip and in some small colonies they can outnumber the typical form. Var. flavescens, which has a pale brown lip, is thought to be a less extreme version of chlorantha.
On the East Sussex Downs back in June, I photographed a Bee Orchid with one flower that I would describe as var. flavescens. I returned to the same plant a week later to find that the original flower was looking more like var. chlorantha. From my own observations, these two varieties appear to be subject to change with age and perhaps all flavescens change to chlorantha over time.
Bee Orchid (Ophrys apifera) (var.flavescens) photographed on 8th June.

The same plant photographed on 15th June. The original (lower) flower is starting to look more like var. chlorantha.

(Reference; "The Orchids of Britain and Ireland" by Anne & Simon Harrap)