Western Ash Bark Beetle (Hylesinus californicus)Latin Name: (Hylesinus californicus)
Common Name: Western Ash Bark Beetle
Appearance:
Adult beetles spend the winter under the bark of ash tree trunks in the bottom 15 cm (six inches).
To catch beetles that emerge in early April, put an adhesive band around the trunk approximately 30 cm (12 inches) above the ground.
Adult beetles are oval, grey and brown beetles that measure about 2-3 mm (1/8 inch) in length.
The larvae are white, C-shaped grubs with a brown head inside the tree.
Host plants:
Green , white ash and autumn purple ash are mainly favored hosts.
Territory:
The western ash bark beetle is distributed throughout the western half of North America.
Damage caused by Western Ash Bark Beetle:
This bug burrows into the bark and wood of ash trees. This digging girdles branches, causing the leaves to become yellow. Beetles typically attack dead or weakening branches, but beetle populations can reach epidemic levels during times of drought or other stress. As the assaults progress, branch dieback may worsen until beetles attack and encircle the trunk, ending in tree mortality.
Life history and Habits:
Adults become active in early to mid-spring, and females dig girdling tunnels beneath the bark. During the tunneling process, tiny ventilation holes are built that are visible from the outside, and sap may leak from the wounds. Adults become active in early to mid-spring, and females dig girdling tunnels beneath the bark. During the tunneling process, tiny ventilation holes are built that are visible from the outside, and sap may leak from the wounds. These tunnels are the primary egg galleries, and they run at right angles to the branch length.
