One little insect in the Xyleborini tribe of beetles has been destroying bay trees and other species in the panhandle at an alarming rate.
Unfortunately the Redbay Ambrosia Beetle attacks healthy trees. Of additional importance, the fungus which causes laurel wilt disease accompanies this beetle and typically causes tree death.
The Redbay Ambrosia Beetle (Xyleborus glabratus) is very small. At about 2 millimeters in length, 15 could fit head to toe in an inch. They are dark brown to black, cylinder-shaped beetles, similar to other ambrosia beetle species found in Florida.
This trunk section of a red bay tree shows stained sapwood, an indication of an infestation by the redbay ambrosia beetle and laurel wilt disease.
The adult female Redbay Ambrosia Beetle has a special pouch in its mouth which transports the spores of the fungus responsible for laurel wilt disease (Raffaelea lauricola). When these beetles bore into the wood, forming galleries, the spores transported in its mouth and on its body infect the tree.
As this pathogen germinates, it colonizes the sapwood of the host plant by using the tree’s circulatory system to spread the disease. The tree is usually doomed at this point.
The Redbay Ambrosia Beetle is native to east Asia, but the origin of the destructive fungus accompanying the beetle is not known. The beetle is believed to have been inadvertently released into Georgia in 2002 through infested packing materials, such as wooden crates and pallets.
Several species of bay, sassafras and avocado trees are all potential hosts for this imported pest. At present there are no registered fungicides for avocado to control laurel wilt.
The best control measures are to not bring in wooden pallets and other similar products which may carry the tiny beetles, their larvae and the fungus. Firewood from distant sources is another potential carrier of this problem species.
As with so many things in life, prevention is much easier than control after the fact.
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