It will forever be remembered as the moth balls final: a rather drab climax to Euro 2016 enlivened by a swarm of moths.

As soon as pictures were broadcast of dozens of moths flapping around the stadium during the warm-up, out fluttered the moth memes. It became a meme swarm for many British critics of the Portuguese captain, after Ronaldo fell, injured, to the turf at the Stade de France, and a moth tended to his arched eyebrow.

Dozens of “Ronaldo’s Moth” Twitter accounts were created within seconds. “The diving bell and the butterfly” joked one wag. “Just put £20 on #Ronaldo swallowing a moth, choking and rolling around on the floor for 20 minutes,” said another.

Ronaldo’s moth was one of thousands of Silver Y moths, a migratory species that moves north through Europe each summer in search of new breeding grounds, returning south in the autumn.

at stade de france, which for some reason is swarming with these moths. all desks covered in their weird moth soot pic.twitter.com/ENzU5GJ9WN — Ken Early (@kenearlys) July 10, 2016

“It’s an obligate migrant species – a proper migratory species,” says Richard Fox of Butterfly Conservation. “Individuals must migrate and choose the right winds to fly at different altitudes to maximise the efficiency of their migration. There’s very clever stuff going on.”

On a warm summer’s evening, the lights of the stadium act like an enormous moth trap, drawing down a migrating front of thousands of these moths.

Pictures show the moths rising from the turf in clouds when the referee, Mark Clattenberg, and officials first stepped on to the pitch. The moths had arrived in the stadium before the footballers – almost certainly drawn down on the previous night when the floodlights were reportedly left on.

“When you’ve got all these big mammals tramping around on the grass, the moths quite sensibly flew up and away,” said Fox.

With winds blowing from the south and south-west over the past few days, Fox said the footballing Silver Ys could end up in Britain. After a miserable wet summer, their presence will at least give people something to spot in the Big Butterfly Count, the world’s biggest insect-recording scheme, which is launched by Butterfly Conservation this Friday.

Ronaldo’s moth-anxiety followed by injury heartbreak turned to joy when Portugal won the tournament. Given that the swarm of Silver Ys proved a lucky omen, perhaps Ronaldo’s crowning glory could be to become their champion: how about honorary president of Butterfly Conservation?