Horse chestnut leaf miners were living on natural stands of trees in Greece a century before they were first described by science, a study shows.
The discovery was made by researchers who examined many of Europe’s historic herbarium collections.
They say it offers an insight to the history and origins of the tiny moths, which are blighting many of the continent’s horse chestnuts.
The findings will appear in Frontiers in Ecology and the Environment journal.
“It is a moth that has been the target of a lot of research recently because it has been expanding [its range] so fast – much faster than other kinds of leaf-mining moths,” explained co-author David Lees from the French Institute for Agricultural Research (INRA).
The larval form of the Cameraria ohridella moth feed inside the leaves of the white flowering horse chestnut tree (Aesculus hippocastanum), producing characteristic “mines” between the leaves’ veins.
The creatures do not kill the tree but infested trees may produce smaller conkers.
Dr Lees said C. ohridella was spreading its range by about 60km (40 miles) across Europe each year.
The small but highly invasive moth was first discovered in 1984, and first described by scientists as a genus new to Europe in just 1986. Since then, it has expanded its range across almost all of Europe.