Emerald Ash Borer, Agrilus planipennis
Buprestidae or Metallic Wood-Boring Beetle Family
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The adults are actually beautiful insects. They
are small, narrow beetles about a quarter to half an inch long, varying
from bright metallic green to metallic copper. The back surface
of the abdomen is metallic purple-red, which is visible when wings are
spread. The head is marked with large black bug-eyes. The
larva is a brownish white grub, about an inch long. The adults feed on ash (Fraxinus species) leaves. When mated, the female lays her eggs in crevices in the bark of ash trees. The hatched larvae burrow through the bark, and then bore long, serpentine tunnels under the bark, eating the living inner bark layer that supports the tree by transporting water and nutrients. When the larva has pupated and become an adult, it chews its way out of the bark, leaving characteristic D-shaped holes. When enough of the living inner bark has been destroyed, the tree will die. Native to northeastern Asia: Russia, Mongolia, Japan, Korea, and northern China. In its native range it is a nuisance pest on native ashes, because its population numbers are kept low by predators and disease. Asian ahses may also be partially resistant. The species is highly invasive in North America and Europe. Without its native predators and diseases, it is highly damaging to native ashes on those continents. It was introduced accidentally into Michigan in the 1990s and has spread outward. As of 2021 it could be found from Nova Scotia , south to Georgia, and west to Manitoba and Texas. All 16 species of North American ash appear to be suspectible and may be decimated. In Wildwood, it is attacking the native White Ash (Fraxinus americana), and may drive it to local extinction. Many dead ashes are already known in Wildwood and nearby areas. Students at RU have studied the damage done by this beetle on Wildwood's White Ashes, and reported |
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