UK butterflies have suffered following the coldest summer for 18 years, the world's biggest butterfly count has revealed.
More than 34,000 people took part in the Big Butterfly Count 2011, seeing 322,000 butterflies and day-flying moths.
But the survey, by Butterfly Conservation, found that the average number of individual butterflies seen per count was down by 11% compared with last year's figures.
The Common Blue butterfly was the biggest loser with numbers down by 61%.
The survey also revealed something of a North/South divide for one species with three times as many Small Tortoiseshells recorded per count in Scotland than in England.
Hopes had been high for a bumper butterfly summer after parts of the UK basked in a record-breaking warm, dry spring.
But the balmy conditions gave way to chilly temperatures and prolonged spells of rain as the summer of 2011 became the coldest since 1993.
Butterfly activity is impaired by low temperatures and heavy rain so they are unable to fly, feed, find mates or lay eggs during bad weather.
Richard Fox, Butterfly Conservation Surveys Manager said: "The fantastic response of the UK public to Big Butterfly Count 2011 has given us a detailed snapshot of how butterflies fared this summer. Twice as many counts were carried out this year as in 2010.
"Unfortunately, the results show that it was a poor summer for butterflies with many species showing declines compared to last year.
"The dismal summer weather, the coldest for 18 years, is undoubtedly to blame, although many butterflies have suffered long-term declines as a result of destruction of their habitats by human activities.
"In bad summers, butterflies need all the help they can get from people to maintain their breeding areas."
Butterflies are key indicators of the health of our environment so the Count results could help provide vital information to help secure their long-term survival.
The Gatekeeper was the most commonly seen species this year, up three places from 2010, but numbers of butterfly were also down by 12%.
The Count also revealed that numbers of Small Tortoiseshell stabilised this year after a recent severe decline.
The perennial garden favourite - the Red Admiral also enjoyed a fantastic summer with numbers up by 98%
For the second year running, the Big Butterfly Count took place in partnership with Marks & Spencer as part of its Plan A commitment towards sustainable farming.
Richard Gillies, M&S Director of Plan A said: "We'd like to thank all of our customers and employees for taking part in this year's Big Butterfly Count, it's great to see that twice as many people took part compared to last year.
"We hope the results and the Count will help to raise awareness about how important butterflies are to the environment."
BIG BUTTERFLY COUNT 2011 - TOP 10 UK SPECIES RANKING
Gatekeeper (52,368 seen)
Small white (47,944)
Large white (42,822)
Meadow Brown (32,183)
Red Admiral (25,400)
Speckled Wood (16,341)
Green-veined White (12,893)
Small Tortoiseshell (12,298)
Six-spot Burnet moth (10,932)