Dark Green Fritillary (Argynnis aglaja) The Dark Green Fritillary (A. aglaja) is the most
widespread fritillary found in the British Isles. Its name is derived from the
green hue found on the underside of the hindwings, which are peppered with
large silver spots. This butterfly can be found throughout the British Isles,
although it is less common in central and eastern England. Outside of central
Scotland and southern England, it is most frequently found in coastal areas and
is the only fritillary found on Orkney and the Outer Hebrides. Despite its
powerful flight, it is somewhat surprising that this species is not
particularly mobile, generally staying within its breeding grounds. A freshly emerged male prepares for flight ...
The Mountain Ringlet (E. epiphron) is probably one of our most difficult species to see.
It is only found in discrete colonies in remote locations, has an
extremely-short flight period (a few weeks only) and can be difficult to find
in anything other than warm bright weather, since the adults tend to remain
sheltered deep in grass tussocks in overcast and cool conditions. Given the
right temperature this butterfly will take to the air as soon as the sun
shines, bringing an apparently dormant landscape to life. As its name suggests,
this butterfly is found in mountainous areas, typically at altitudes between
450m and 800m AMSL though can be found at both lower and higher levels; as per
the example figured (from around 350m AMSL). E. epiphron forms discrete colonies in particular areas of the
mountains they inhabit and, on good sites, may be seen by the hundred. This is
typical of epiphron - localities may
be few and far between, but where they occur the butterfly is often found in
is found in two main regions in the British Isles. In England, it is found in
the Lake District of Cumberland and Westmorland. It is also found in western
central Scotland, primarily in the counties of Argyllshire, West Inverness-shire
and Mid Perthshire with a few scattered colonies elsewhere. It is surprisingly
absent from Snowdonia and the Pennines. On the basis of four specimens in total
(seven are reputed, with four considered by most authorities to be genuine),
this butterfly is also thought to have occurred in Ireland (see references
There is one generation each year, with adults
emerging at the start of June in the Lake District and early July in Scotland.
A recent visit to Irton Fell, with my
good friend Peter Eeles, produced numbers in excess of 150 (a male is figured above), with the peak of
sightings being achieved on the higher slopes close to Greathall Gill and Whin
Rigg. We were particularly pleased to watch a female ovipositing on Mat-grass (Nardus stricta). The eggs, which are pale cream at first, develop red-brown blotches after a few days. They are relatively large compared with the size of the butterfly, with each female laying up to 70 eggs. This stage lasts around two or three weeks depending on the weather
The Purple Hairstreak (F. quercus) is our commonest hairstreak, and may be located in oak
woodland throughout southern Britain, and more locally elsewhere. It is often
difficult to locate, due to its habit of flying high in the tree canopy, where it
feeds on honeydew; groups of several individuals chasing one another is not an uncommon sight. However, the adults are occasionally seen feeding and basking at lower levels,
on various small trees, shrubs and bracken. This butterfly is found across
southern England and Wales, with scattered colonies further north. It is also
found in parts of Ireland, mainly between Wicklow and South Kerry.
It is primarily found in woodland
containing oak trees, the foodplant of the larva. However, the species can be
found in any location where oaks occur, including lanes, parks, gardens, and
other urban areas. The primary larval foodplants are Pendunculate Oak (Quercus robur), Sessile Oag (Q. petraea) and Turkey Oak (Q. cerris). Evergreen Oak (Q. ilex) is also used.
Eggs are laid singly (or less commonly, in groups
of 2 or more), usually at the base of a plump oak bud, or cluster of buds, but
can also be found on an adjoining twig and at various heights. They are laid on
branches that are sheltered and receive full sunshine - such branches are
therefore on the southern side of the tree. There also appears to be a
preference for solitary trees, such as those found at the edges of woods, or
those that form part of a hedgerow. Eggs are also most-often found on
relatively mature trees (since these have the plumpest buds) on branches that
are twisted and gnarled. Eggs are relatively easy to find in suitable locations
during the winter months before the oak buds burst. Emergence occurs from the last week of June, through July and into August, with adults still being found into September. There is generally a peak at the end of July and early August, or later in Scotland. There is one brood each season.
This delightful butterfly, a female pictured above, is one of our most threatened species and
has suffered severe declines in recent decades. Although declining throughout
Europe, the British Isles is considered one of the few strongholds for this
species. However, the reclamation of wetlands and the ploughing up of downland
has meant that E. aurinia has now
disappeared from many counties and has also suffered severe declines in the
British Isles; this butterfly is therefore a priority species for conservation
efforts. Although still widespread in some parts of its range, this butterfly
is reputedly declining by over 10% each decade. The deteriorating fortunes of
this species are believed to be the result of inappropriate habitat management,
coupled with the need for sufficient habitat for the butterfly to form meta-populations, where local
extinctions can be reversed by recolonisation from neighbouring colonies. It is
currently found in southwest England with a small population in northwest
England, the islands of southwestern Scotland and the adjacent mainland, and
northwest and southwest Wales. It is also locally widespread in Ireland.
positive note, aurinia is an easy
species to breed in large numbers in captivity and one, which lends itself to
reintroduction or establishment in suitable areas where its main foodplant,
Devil’s-bit Scabious (Succisa pratensis), grows in some profusion. My
late good friends, the respected entomologists Peter Cribb and Peter Taylor,
both kept healthy stocks of this species going for well over 25 years and bred
thousands of healthy specimens for release purposes in various counties in the
south of England. In Sussex, the former Ditchling Common colony originated from
this source with the original stock coming from just over the border in Surrey.
Colonies of E.
aurinia are known to fluctuate wildly in population density. It may be
present in good quantities one year, only for the population to crash
dramatically the following season without any apparent reason - before
recovering just as unexpectedly. It does not do well in adverse weather
conditions and can suffer significantly from the attentions of parasitic
hymenoptera during the larval stage. Adults, which typically emerge in the
middle of May, reach their peak in early June. In northern Scotland they emerge
slightly later. There is one generation each year.
Where it occurs, aurinia uses several different types of habitat, including chalk
hillsides, heathland, moorland and damp meadows. A factor common to all
habitats is that they are in full sun, their higher temperature aiding larval
previously mentioned, the primary larval foodplant is Devil’s-bit
Scabious (Succisa pratensis). Field
Scabious (Knautia arvensis) and Small
Scabious (Scabiosa columbaria) are
On emerging from their eggs the larvae spin a silk web, by binding together leaves of the foodplant, in which they live and feed. Larvae build new webs as they grow and even move to a new plant if necessary. In later instars, the webs can be quite conspicuous. Larvae will also bask on the outside of the ‘tent’ absorbing the sun's rays, where their increased temperature aids digestion. After the third moult the larvae build a dense nest of silk low down in vegetation in which they hibernate. Larvae will emerge from their nest with the onset of spring and can be seen basking in warm sun as early as February. The larvae eventually split into smaller groups, continuing to build silk webs where they bask communally to keep their body temperature relatively high, even on cool days. More-mature larvae tend to feed alone and are often found wandering across open ground looking for their next meal or, eventually, a pupation site. There are 5 moults in total. The pupa (pictured above) is formed head down,
attached to a twig or plant stem by the cremaster. The pupa is essentially
white, with a beautiful mix of black, brown and orange markings. This stage
lasts between 2 and 4 weeks, depending on temperature.
The Golden-bloomed Grey Longhorn (A. villosoviridescens)
Cerambycidae, the Longhorn beetles, are a very impressive group of insects.
The family, which includes some of Britain’s most impressive beetles, currently
numbers around 70 species. Many striking examples can be found abroad. They are predominantly beetles that develop in
wood, with the adults being active during the spring and summer months. However,
A. villosoviridescensis an exception to this rule, developing in the stems of a variety of herbaceous
plants including Cardus,
Urtica, Angelica, Chaerophyllum,
Artemisia, Salvia and Aconitum.The larvae develop in the above-ground plant tissues. They cut off the
plant stalk before pupation, create the pupal cells near ground level, and the
adults leave the stalks via a newly created exit hole in the side of the
remaining stalk. The above specimen, one of four observed, was found sitting on Hemp-agrimony (Eupatorium cannabinum) at a West Sussex wetland site. My first encounter with this impressive species …
European Stonechat (S. rubicola) is a fairly common resident and partial
migrant to Sussex. They are associated with two main breeding areas:
heathland and downland with gorse and scrub. Ashdown Forest in East Sussex
holds about 50-70% of the county total of circa 150-200 pairs; this out of a
national population of circa 56,000 pairs. They are typically seen perching on the tops of bushes in otherwise rather
open places, with favoured locations being regularly visited.
attractive bird and one that is always a pleasure to see …
Scott-Ham, M., 2014. European Stonechat. The
Birds of Sussex. Thetford: British Trust for Ornithology (BTO) Books on
behalf of the Sussex Ornithological Society, pp. 518-519.
Scott-Ham, M., 1996. Stonechat. Birds of
Sussex. Sussex Ornithological Society, pp. 424-425.