Spring is maple syrup time in northern areas. However, the prized maple trees that give us this sweet sap are under attack. The villain is the Asian long-horned beetle (Anaplophora glabri-pennis), a pest from China that's relatively new to North America.
This beetle has a 1-inch-long bullet-shaped black body with irregular white spots. Its 2-inch-long black antennae have white rings. Adults lay eggs in the bark in spring and fall, and the inch-long white larvae bore into trees, creating 1/2-inch-diameter holes and tunnels that can kill a mature tree in one year. The insects' preferred hosts are sugar and Norway maples, but they also attack apple, cherry, elm, horse chestnut, locust, mulberry, pear, poplar, and willow trees.
The Asian long-horned beetle can survive in most areas of this country. It has no known predators, and chemical sprays are considered ineffective because the larvae and adults burrow so deep into the tree. The only defense is to cut down the tree and burn the wood.
These pests apparently hopped a ride on wooden crates used to ship products from China. Crates containing the beetles have been found in many states, but the outbreaks have been limited to Chicago and New York. The concern is that, even though the beetle does not naturally move far from host trees, transporting infested firewood and branches may accidentally move it to new areas. Quarantines have been set up in areas identified as having the beetles, and infested trees are being destroyed. To help prevent more beetles from entering the country, the federal government has implemented new rules for treating wooden crates from China.
The best defense against this insect is exclusion. Home gardeners can help by checking deciduous trees for 1/2-inch-diameter holes in the branches and trunk with lots of sawdust nearby. Also be on the lookout for the adult beetle from July to October. Report sightings in the Chicago area to (800)641-3934. In New York, call (800) 201-7275. Elsewhere, contact your state's department of agriculture. To help with identification, also see their Web site .
Article published on June 23, 2008.