Butterfly Islands: September 2018

Monday, 17 September 2018

More Late Summer Butterflies.

At this time in late summer, the Clouded Yellow can sometimes be seen dashing around our fields and open woods.Most originate from mainland Europe,however I am sure that here on the south coast we have our own 'home grown' individuals.

In Bouldnor Forest near Yarmouth there is an open area in the woodland.Here a group of almost dried out scrape ponds are surrounded by low scrub and gorse bushes.Yellow Fleabane is prolific and a favourite for nectaring butterflies and today under sunny skies there were no shortage of species.As well as the Clouded Yellow, Common Blue,Small Copper,Wall Brown,Red Admiral,and a Painted Lady were on show.

Friday, 14 September 2018

Late Summer Butterflies on the Landslip.

Today on the landslip beneath the coastal cliffs along the south west shore of the Isle of Wight there was a good selection of late summer butterflies.This unique area is well known for the Glanville Fritillary butterfly during May and June.A strong onshore wind blew today but in any sheltered spot,especially where yellow fleabane is flowering the butterflies congregated.Many seemed to be a excellent condition with Common Blue particularly striking.Surprisingly the Wall Brown proved to be the most numerous,as these coastal cliffs are a favourite for this species.Other butterflies on the wing were Peacock,Small Copper,Small Heath,and two flyby Clouded Yellow.

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.