Millions of painted lady butterflies could be heading to Britain in a once-in-a-decade mass migration from southern Europe.
Unusually high numbers of the orange and blackinsects have been reported in southern Europe at the critical time of year for them to spread north towards the UK.
Painted ladies commonly migrate in varying numbers from the continent to Britain each summer, where the caterpillars feed on thistles. But around once every 10 years the UK experiences a "painted lady summer" when millions descend as part of the longest butterfly migration in the world, Butterfly Conservation said.
The last mass migration took place in 2009 when around 11 million painted ladies winged their way across to the UK, including to the most northerly parts of Scotland.
Since then the UK has had five years with below average numbers, but scientists are confident that 2015 could be different.
Butterfly Conservation reported that some butterflies arrived in mid-May but a spell of poor weather temporarily halted the migration. However, recent warm conditions have seen painted lady numbers soar again, with reports of large numbers on parts of the south coast. The public is being asked by Butterfly Conservation to record sightings of painted ladies through its Migrant Watch scheme to help chart the progress of any potential migration during the summer.