The bronze birch borer,
Agrilus anxius, is a beetle from the family Buprestidae whose larvae cause great damage to birch species (
Betula) by feeding on the bark and cambium of the tree. Tunneling resulting from larval infestations block nutrient and sap flow from leaves to tree roots, and trees with infestations show yellow leaves and dieback starting at the top of the tree, which if unchecked, progresses downward until the tree succumbs. The bronze birch borer is native to North America, where it attacks all species of birch trees, however, indigenous American species, including paper birch (
Betula papyrifera Marshall), 'Whitespire' gray birch
Betula populifolia Marshall), and river birch (
Betula nigra ), survive colonization of bronze birch borers far more successfully than European and Asian natives (European white birch
Betula pendula Roth; downy birch
Betula pubescens Ehrh.; monarch birch
Betula maximowicziana Regel; and Szechuan white birch
Betula szechuanica Jansson). This implies that
A. anxius would pose a strong threat to birch populations if it were inadvertently introduced into Europe or Asia (such as through imported wood chips, which are commonly traded for biofuel production).
Agrilus anxius larvae are small enough to survive chipping, and it is recommended that contaminated wood be burned to reduce spread of this pest.
(
European and Mediterranean plant protection organization 2011; Barter 1957;
Wikipedia 2008)
