The Chequered Skipper, which is extinct in England, is now only known to occur in the UK within a 30-mile radius of Fort William in the Highlands.
However, recent work by Butterfly Conservation Scotland and the Joint Nature Conservation Committee (JNCC) has predicted the butterfly could have been living unnoticed in many other parts of the country, including parts of Sutherland, Wester Ross and the Isle of Mull.
Butterfly Conservation Scotland is calling for the public to take part in a survey, reporting sightings of the small butterfly, so they can work out the true extent of its population.
Dr Tom Prescott, senior conservation officer for Butterfly Conservation Scotland, said: “The Chequered Skipper is a rare and enigmatic butterfly which we believe is probably more widespread than current records suggest.
“We have identified 100 one-kilometre squares where we think the butterfly should occur but we do not have any sightings.
“We would like the public to get involved and see if this is true by looking for the butterfly in these areas”
The Chequered Skipper is usually on the wing from mid May until the end of June. It can be seen on warm and sunny days, even during brief spells of sunshine, feeding on nectar particularly bugle, marsh thistle and orchids.
It was formerly found in England, where it used to be relatively common in East
Midland woodlands. But it began to decline in the 1960s before finally being declared extinct in 1976.
The butterfly’s preference for the small area near Fort William in the Highlands is thought to be due the area’s warm, damp summers and mild winters, which allow the deciduous Purple Moor-grass, on which the caterpillar feeds, to stay green late into the autumn.
This helps the caterpillars to complete their development before hibernating for the winter.
Elsewhere in the UK, Purple Moor-grass turns brown too early in the year for this to happen.
To take part visit www.butterflyconservation.org/chequeredskipper