Butterfly Islands: July 2017

Wednesday, 19 July 2017

Not Many Silver-studded Blues on Show.

Yesterday on a day trip to see the special damselflies of Crockford Stream in the New Forest I walked an area of heathland which was close by.I expected to see good numbers of Silver-studded Blue here, but numbers were low and all were faded and worn.Perhaps this is a result of early emergence as has occurred with many species this year. However, I did find a Blue in very reasonable condition near to the stream.

Other butterflies on show were Gatekeepers in abundance and a few Grayling on the heath.

New Forest Heathland,habitat for Silver-studded Blue & Grayling

Tuesday, 11 July 2017

White-letter Hairsreaks Still Busy.

Yesterday as I observed the elm that has been home to White-letter Hairstreaks for the last three seasons I was fortunate to see a female wandering along a branch in search of buds on which to lay her eggs.This carried on for some time as she fluttered onto other branches in pursuit of more buds.

Monday, 10 July 2017

Last of the Summer Blues Now on the Wing.

There were plenty of Chalk-hill Blues on the bridleway leading to West High Down today.Not surprisingly all are males but it will not be long before both males and females are on our chalk downland in their hundreds.Apart from the Adonis Blue perhaps, this must be one of our most colourful blues.

Saturday, 8 July 2017

Good Season for Silver-washed.

It seems to be an excellent season for the Silver-washed Fritillary. Good numbers are to be seen in our woodlands and if lucky the odd female Valezina form could turn up.It is estimated that one in seven females have this attractive appearance.

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.