Butterfly Islands: May 2017

Monday, 22 May 2017

A Splash of Colour.

With settled and warm weather a definite prospect for the next few days the season is well under way.Today the pyracantha bush in the garden looked magnificent as a deluge of flowers began to open.This attracted my first Painted Lady of the year,a very pristine individual.Despite my attention it returned several times to take advantage of the blooms and that glimpse of orange and red on the underside plus the gold and blue of the underside rings was an enjoyable treat.

Yesterday while on the cliffs and landslip of our southwest coast I came across a Small Copper sporting several blue iridescent pear shaped spots on the hind wings.This is the aberration caeruleopunctata,not an uncommon form but it can vary from having one or two faint spots through to five clearly defined pear-shaped marking on each hind wing.

Sunday, 21 May 2017

Glanvilles Showing Well.

At this time of year the cliffs on the Isle of Wight are carpeted in Thrift and these drifts of bright pink attract insects, in particular the butterflies.The number of Glanville Fritillaries are now on the increase and today I saw many on the landslip.The peak of their season has yet to arrive and hopefully there will be many more on the wing during the next few weeks.

Tuesday, 9 May 2017

First Adonis Blue & Glanville Count Rises.

With Adonis Blue already reported from several mainland locations,I decided to try my luck today on Bonchurch Down.The numbers of Adonis have decreased in recent years due to less than ideal land management on the Down and the fall in the rabbit population.The Adonis require short downland grass to be successful and the lack of grazers such as the rabbit has allowed the grass to grow long.A check of the male Common Blue butterflies encountered today led to my first record of the year of a Adonis Blue.These two species are very similar,but close inspection will leave no doubt if it is an Adonis. The spectacular and striking sky blue of the male Adonis is unmistakeable.

Not too far away is the premier site for the Glanville Fritillary and since the first appearance of this special butterfly four days ago numbers have steadily increased.Todays count amounted to eight pristine fritillaries all resplendent with their orange and brown chequered wings and a white border.The underside has a pattern of cream and orange bands with black marks.

Sunday, 7 May 2017

Glanville Fritillary Takes to the Air.

Following yesterdays report of the first Glanville Fritillary on the wing in 2017 I made the trip to the south of the Isle of Wight in the hope of seeing this special butterfly.The Island has the only natural habitat for this butterfly in the UK, so it is always an unique event when the Glanville makes its first appearance.

After some searching the one individual was spotted busily feeding on a variety of the many plants that are flowering at this site.The sighting was all too brief as it flew off up the slope and was not seen again. Still,we can look forward to seeing more Glanvilles in the next few days as they emerge on the cliff tops along the Island's south-west coast.
Other species were in the main absent,although it was encouraging to see at least six Common Blue feeding on the abundant Red Valerian.

The Adonis Blue

The Large Tortoiseshell

It seems the general view on the status of the Large Tortoiseshell in Britain is that it is now extinct as a breeding butterfly.
It is a butterfly of woodland edges and hedgerows that abound in willows,elms,and poplars.These trees are used by the adult to lay its eggs and this single brood appears in July and August.The emerging butterfly then hibernates over the winter in log piles and hollow trees until the next spring.
On the Isle of Wight sightings are more often than not made from early March to April.Have these butterflies overwintered on the Island or have they come from the continent where it is common?
Any sightings made in July/August pose the same question.Another explanation could be that captive-bred releases are responsible.Only the discovery of eggs and caterpillars will probably answer these questions.

I can now report that evidence has been found of breeding just along the coast at Portland in Dorset (June 2020) and again at the same location in the summer of 2021.

The Glanville Fritillary

This elegant butterfly is mainly confined to the crumbling undercliffs and chalk downs of the Isle of Wight.It is also found on the Channel Islands and at one or two isolated colonies on the British mainland.In Britain the Glanville Fritillary is at the extreme north-western edge of its range.On the continent it is readily found in flowery habitats.
Around the southern shores of the Isle of Wight the cliffs constantly erode causing them to slip away and provide perfect conditions for new growths of the butterflies laval host plant,Ribwort Plantain.
The eggs are laid to the underside of the leaves of this plant and normally hatch after about three weeks.The resulting caterpillars live together in communal webs spun over the plantain.In the autumn they hibernate and recommence feeding in the spring,eventually dispersing to prepare for pupation.
The adult butterfly is on the wing from May to the end of June with the female being larger than the male.They will feed on,amongst other things, Birds-foot Trefoil and Thrift.

The Wall Brown

On the Isle of Wight in particular,the Wall Brown is a butterfly of field edges,coastal cliffs and dunes,and rabbit-grazed downland.
The male is territorial and spends much of the time patrolling and basking on the ground.
The female,which lacks the males conspicuous dark sex brand across the forewings,is larger.The undersides of both sexes are beautifully cryptic when at rest.
The Wall Brown generally produces two broods a year,the first from late April until late June and the second from mid-July to mid-September.