'Blind' male (wings open) with male large ringlet (I believe),
Switzerland, July 2017
The next picture shows the same pair, in the same respective positions.
Switzerland, July 2017
Switzerland, August 2013
Male, Switzerland, June 2017
Female, Switzerland, July 2016
Switzerland, June 2005
Switzerland, July 2005
Switzerland, July 2007
Switzerland, August 2008
Distribution
This is a common Erebia
of woodland rides and sheltered, grassy clearings, often with bramble
or bracken, on which the adults love to bask. Its English name reflects
its alleged former presence on the Isle of Arran in Scotland. Certainly
there exist historic specimens giving this as their provenance, but
there is no undisputed evidence this was ever a British butterfly. In
Switzerland, the first adults appear in June, with the main emergence
in July, though as ever this depends upon altitude. In my local woods,
this species always appears some weeks before the similar Scotch argus,
which flies in many of the same places.
The Arran brown is a large, bold ringlet. The red bands on the
upperside are complete on forewing and hindwing, and each usually
contain three or four white-pupilled black eyespots. In my part of
Switzerland, however, these eyespots are not infrequently blind, giving
rise to potential confusion with the large ringlet. This latter,
however, despite its name, is smaller, with less developed red bands on
the upperside and usually smaller eyespots. In most places, the
eyespots of large ringlet are blind, but in much of Switzerland form adyte,
with white pupils flies, adding to the confusion with Arran brown.
Fortunately, the undersides are distinct. Arran browns have a
characteristic white 'paint splash' towards the costa of the hindwing,
and at least three red-ringed eyespots on this wing too. The female
large ringlet may have a vaguely similar white pattern, but it is set
in a pale band and cross the whole wing, with a strong tooth in the
middle. She has much weaker eyespots on the underside hindwing. The
male large ringlet has at most a white tooth in the middle of the wing
and quite inconspicuous eyespots. Arran brown, large ringlet and Scotch
argus (principally the female) are the only ringlets to have an
obviously chequered fringe.
Eggs are laid on sedges and the butterfly hibernates as an egg
or
small caterpillar. Arran browns fly in a single brood through until
about the end of August.
