Britain's butterflies suffered a "catastrophic" year in 2012 with almost all species declining as a result of torrential rains, according to a study published on Tuesday.
Of the 56 species studied by the UK Butterfly Monitoring Scheme, 52 saw a drop in numbers as Britain's second-wettest year on record left the colourful insects struggling to find food, shelter and mates.
Several British species are close to extinction and the study warned that the wet weather could wipe them out in parts of the country.
"Many of our most threatened butterflies were already in a state of long-term decline prior to the 2012 deluge," said the Centre for Ecology and Hydrology, which runs the monitoring scheme with the charity Butterfly Conservation.
"There are now real fears that these already struggling species could become extinct in some parts of the UK as a result of last year's wet weather."
The critically endangered high brown fritillary, which has orange wings with dark spots, saw its population shrink by 46 percent over the year, while numbers of the endangered heath fritillary fell by a half.
The black hairstreak, one of Britain's rarest butterfly species, suffered a 98 percent drop in numbers.
For 13 species, 2012 was the worst year since the monitoring scheme began in 1976.
Common species also suffered, with numbers of the brown argus plummeting by 73 percent and the common blue, loved for its bright lilac colour, dropping 60 percent.
"2012 was a catastrophic year for almost all of our butterflies, halting progress made through our conservation efforts in recent years," said Tom Brereton, head of monitoring at Butterfly Conservation.
"With numbers in almost three-quarters of UK species at a historically low ebb any tangible recovery will be more difficult than ever."
But the wet weather was a bonus for the few species that favour the damp, with four species enjoying rising numbers in 2012, according to the study.
Numbers of the scotch argus rose by 55 percent, while the grass-feeding meadow brown saw its numbers swell by 21 percent.
The data was collected by thousands of butterfly-loving volunteers who braved the downpours to monitor the insects at more than 1,000 sites across Britain throughout the summer.
Swathes of Britain were hit by flooding in 2012. At least three people died in floods in southwest England and Wales in November, while torrential rains caused widespread disruption to the road and rail network in the run-up to Christmas.