Some of Britain's most beautiful moths, such as the garden tiger, have crashed in numbers over the past 40 years as part of a widespread decline, conservationists warned today.
Two -thirds of common larger species (macro-moths) have declined in that time, with losses much greater in southern Britain than in the North, according to the Butterfly Conservation charity and agricultural analysts at Rothamsted Research.
Three species have become extinct in the past decade, while once common garden varieties such as the garden tiger moth, V-moth and spinach moth decreased by more than 90 per cent between 1968 and 2007 and now face the threat of extinction.
The analysts' report, The State of Britain's Larger Moths 2013, reveals that the orange upperwing moth, the bordered Gothic and the Brighton wainscot have all disappeared in the past 10 years, following the extinctions of another 62 species during the 20th century. The report is based on the Rothamsted Insect Survey, a series of records running from 1968 to 2007 and covering common and widespread species. It suggests that ongoing habitat loss and the deteriorating condition of the countryside are probably major factors behind the declines.
Two-thirds of the species recorded declined over the 40-year study, with 37 per cent decreasing by at least half. Numbers of garden tiger moths are down by 92 per cent, spinach moths by 96 per cent and V-moths by 99 per cent. The loss of tiger moths may be contributing the disappearance from southern Britain of cuckoos, which feed on their hairy caterpillars.
In southern Britain, larger moth populations fell by an average of 43 per cent in comparison to an average 11 per cent decline in the North. The reason for the disparity is likely to be the greater habitat loss in the South and the beneficial effects of climate warming on some moths in the North.
While populations have declined substantially in the past few decades, the period has also seen an unprecedented influx of new moth species to Britain. More than 100 have been recorded here for the first time this century and 27 species have colonised from the year 2000 onwards.
"This report paints a bleak picture about Britain's biodiversity," said Richard Fox, the surveys manager and the lead author of the study. "Much has been made of the decline of butterflies and honey bees but moths represent the massive, but largely unnoticed diversity of insects that form the vast majority of animal life in Britain."