Adult female Asian longhorned beetle
Michael Bohne, USDA Forest Service, Bugwood.org
Asian Longhorned Beetle
The Asian longhorned beetle (ALB) has been discovered attacking trees in the U.S. It probably traveled to the U.S. inside solid wood packing material from China.
Keywords: maples, Acer species, Coleoptera, ALB, jet black body, mottled white spots, long antennae, egg-laying niches, tunnels, girdling, crown dieback
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Asian longhorned beetle distribution
In the U.S., ALB prefers maple species, including boxelder, Norway, red, silver, and sugar maples. Other known hosts are alders, birches, elms, horsechestnut, poplars, and willows. Adults have a jet black body with mottled white spots on the back and are ¾ to 1¼ in. long. Long antennae are 1½ to 2½ times the body length with distinctive black and white bands on each segment. ALB has one generation per year. Egg-laying niches are chewed out of the bark by the female beetle, and a single egg is deposited in each niche. Each female is capable of laying up to 160 eggs. Eggs hatch in 10-15 days, and the larvae tunnel under the bark into the wood where they eventually pupate. Tunneling by larvae girdles tree stems and branches. In the summer, sap may flow from egg niches, especially on maple trees, as larvae feed inside the tree. Adults emerge from pupation sites by boring a tunnel in the wood and creating a round exit hole 3/8 in. in diameter or larger in the tree. Adults usually stay on the trees from which they emerged or may disperse short distances to a new host to feed and reproduce. Repeated ALB attacks lead to dieback of the tree crown and, eventually, death of the tree.