Managed by Gloucestershire Wildlife Trust, with the kind help from some
Welsh mountain ponies from Butt’s Farm (a rare breed farm in Cirencester) the
reserve provides the large blue with a unique habitat and special conditions in
which to breed.
The
butterfly relies on another species to help it’s lifespan along the way, a red
ant called Myrmica sabuleti which lays its eggs on wild thyme. Once hatched,
the caterpillars feed on the thyme before dropping to the ground where the
red ants mistake them for ant larvae and take them into their colonies.
There the butterfly larvae feed on ant larvae until they emerge as
butterflies.
There’s
a very short window in which to see the large blues, but if the weather
conditions stay good they might be around for about two weeks
if a visit is planned to see what must be one of our rarest
species.