The slender scotch burnet is thought to live at very few sites

The slender scotch burnet can only be found on Mull and Ulva, according to Butterfly Conservation Scotland.

It is thought to have died out on the Highland mainland. The conservation group is looking for help clearing cotoneaster, a non-native plant.

The volunteer event is being held on Friday 24 and Saturday 25 August from 1030 to 1700 BST.

The moth is known to inhabit six or seven sites on the islands, but before 1945 could also be found on Morvern in Argyll and elsewhere on the Highland mainland.

Butterfly Conservation Scotland said the slender scotch burnet is restricted to steep slopes with a sunny, south-facing aspect near the coast.

Its larvae feed on bird's-foot trefoil, which is threatened by scrub, bracken and cotoneaster.

For further details on volunteering e-mail [email protected], or call 01540 661469.