Butterflies could lose their spots as climate change accelerates, research at the University of Exeter's Penryn Campus has revealed.

Scientists discovered a correlation between rising temperatures and the number of spots on female Meadow Brown butterflies.

Females developing at 11 degrees celsius averaged six spots, whereas those at a warmer 15 degrees celsius had just three spots.

This pattern challenges pre-existing notions on why the butterflies possess varied spot quantities.

Professor Richard ffrench-Constant, from the Centre for Ecology and Conservation on Exeter’s Penryn Campus in Cornwall, explained: "Meadow Browns always have large ‘eyespots’ on their forewings, probably for startling predators.

"They also have smaller spots on their hindwings, likely useful for camouflage when the butterfly is at rest."

The investigation highlighted how these butterflies seem to adapt their camouflage to suit their environment.

He added: "Our findings show that fewer of these hindwing spots appear when females experience higher temperatures during their pupal stage.

"This suggests the butterflies adapt their camouflage based on the conditions.

"For example, with fewer spots they may be harder to spot on dry, brown grass that would be more common in hot weather."

These effects weren't seen as strongly in male butterflies, possibly due to their spots being vital for attracting females.

The Meadow Brown butterfly’s eyespot variation has long been used as a prime example of 'genetic polymorphism', a term signifying the co-existence of multiple genetic forms in one population.

This new study, however, suggests that this variation is driven by thermal plasticity, the ability to respond to changing temperatures.

Professor ffrench-Constant added: "This is a family story for me, as my father collected butterflies for EB Ford here in Cornwall.

"In the new study, we looked at current Cornish populations and historical collections from Eton and Buckingham."

As our climate continues to warm, scientists predict a subsequent decrease in butterfly spotting.

"This is an unexpected consequence of climate change.

"We tend to think about species moving north, rather than changing appearance," Professor ffrench-Constant said.

The study, entitled: 'Eyespot variation and field temperature in the Meadow Brown butterfly', was published in the journal Ecology and Evolution.