As annual three-week survey kicks off, there are signs weather has taken toll on populations of common species
Last summer’s drought may have reduced butterfly populations this year because grasses and flowers that would usually feed caterpillars withered and died in the heatwave, scientists say.
People are being urged to help researchers understand the impact of extreme weather on British butterflies by counting the number and species they see this summer as part of the world’s largest insect survey.
