Wolcott Garden Treasures
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Asian Longhorn Beetle
An adult Asian Longhorn Beetle
Egg niches
Exit holes
Sawdust or "frass"
Although strikingly beautiful, the Asian Longhorn Beetle (ALB) is causing a lot of destruction nearby, and a lot of worry here in Connecticut. This hardwood boring insect came over from China and Korea, most likely in wooden packing & shipping materials, like pallets.
In August of 2008 the first ALB was discovered in the United States in Worcester, Massachusetts by a citizen, who reported it to the USDA. Between the time of the first infestation and October of 2009, there have been over 25,000 trees cut down in a two mile radius. It's not only a safety measure, but a necessity: once a tree has been infested, no chemical pest control measure will eradicate the beetle. It takes about five years for the ALB to kill a tree, but it will die, so detection of the beetle and removal & destruction of the tree is the only way to prevent further spread.
Worcester, Shrewsbury and Wachusett have already been placed under quarantine and the shipment of hardwoods (i.e., firewood) out of those areas is heavily regulated, but being so close, Connecticut officials are understandably worried that the ALB will find its way here. Luckily, it is a big, lazy beetle that prefers to walk only up the tree where it was laid as an egg, rather than fly to another area (although it is capable of flying short distances). Unluckily, once the original host tree has died, the ALB will travel down the trunk and across the ground until it finds another host tree. Also, the beetles start their damage at the top of trees, where the problem is masked by healthy, green foliage that shows little sign of stress until the tree is completely infested. Not only that, the ALB is not very picky when it comes to a host: maples, boxelders, horse chestnuts, buckeyes, willows, elms, birches, ashes, sycamores and poplars are all fair game.
Spotting the boring damage: An adult female ALB will chew a round niche into the bark of a tree and lay a single egg in each. The egg is only about the size of a grain of rice, so spotting the nesting area is more likely. The female will lay 35-90 of these eggs, and they hatch in 10-15 days! After hatching, the larva will bore a hole fairly deep into the hardwood of the tree, where it will live until metamorphosis is complete. The adult will then chew its way back out to the bark surface, leaving behind a perfectly round hole just a bit smaller than a dime in diameter.
Spotting the adult: The adult beetle, itself, is very identifiable: it is large, at 3/4" to over 1" long, and is actually really beautiful, with striking black and white coloring, and long, black and white banded antenna.
Identifying damage to the tree: A tree will show very few signs of distress until it is heavily infested. A damaged tree will often drop its leaves early, and the chewing of the leaves is very noticeable. Adult ALBs chew the veins of the leaves, so green leaves with removed veins on the ground are a dead giveaway. Also, the boring action of the larva creates toothpick-like sawdust that will often accumulate in crotches where branches meet the main stem or other branches. Finally, egg niches are fairly visible and often cause the tree to secrete sap, so unusual sap leakage may also be a clue.
So what can you do to help? If you suspect or see an Asian Longhorn Beetle, call the Connecticut Agricultural Experiment Station at (203) 974-8474 right away and give as much information as possible. Pictures of the damaged tree are very helpful. If you spot an adult beetle, please take care not to handle it with bare hands! They will bite and draw blood! If you catch one, put it in a metal or glass jar/canister and put it directly in the freezer. The ALB can chew through any materials besides glass and metal.
Thank you so much for doing your part! We love our beautiful, native, mature trees and want to do everything we can to keep them healthy and safe!
All photos on this page courtesy of Beetle Busters.
In August of 2008 the first ALB was discovered in the United States in Worcester, Massachusetts by a citizen, who reported it to the USDA. Between the time of the first infestation and October of 2009, there have been over 25,000 trees cut down in a two mile radius. It's not only a safety measure, but a necessity: once a tree has been infested, no chemical pest control measure will eradicate the beetle. It takes about five years for the ALB to kill a tree, but it will die, so detection of the beetle and removal & destruction of the tree is the only way to prevent further spread.
Worcester, Shrewsbury and Wachusett have already been placed under quarantine and the shipment of hardwoods (i.e., firewood) out of those areas is heavily regulated, but being so close, Connecticut officials are understandably worried that the ALB will find its way here. Luckily, it is a big, lazy beetle that prefers to walk only up the tree where it was laid as an egg, rather than fly to another area (although it is capable of flying short distances). Unluckily, once the original host tree has died, the ALB will travel down the trunk and across the ground until it finds another host tree. Also, the beetles start their damage at the top of trees, where the problem is masked by healthy, green foliage that shows little sign of stress until the tree is completely infested. Not only that, the ALB is not very picky when it comes to a host: maples, boxelders, horse chestnuts, buckeyes, willows, elms, birches, ashes, sycamores and poplars are all fair game.
Spotting the boring damage: An adult female ALB will chew a round niche into the bark of a tree and lay a single egg in each. The egg is only about the size of a grain of rice, so spotting the nesting area is more likely. The female will lay 35-90 of these eggs, and they hatch in 10-15 days! After hatching, the larva will bore a hole fairly deep into the hardwood of the tree, where it will live until metamorphosis is complete. The adult will then chew its way back out to the bark surface, leaving behind a perfectly round hole just a bit smaller than a dime in diameter.
Spotting the adult: The adult beetle, itself, is very identifiable: it is large, at 3/4" to over 1" long, and is actually really beautiful, with striking black and white coloring, and long, black and white banded antenna.
Identifying damage to the tree: A tree will show very few signs of distress until it is heavily infested. A damaged tree will often drop its leaves early, and the chewing of the leaves is very noticeable. Adult ALBs chew the veins of the leaves, so green leaves with removed veins on the ground are a dead giveaway. Also, the boring action of the larva creates toothpick-like sawdust that will often accumulate in crotches where branches meet the main stem or other branches. Finally, egg niches are fairly visible and often cause the tree to secrete sap, so unusual sap leakage may also be a clue.
So what can you do to help? If you suspect or see an Asian Longhorn Beetle, call the Connecticut Agricultural Experiment Station at (203) 974-8474 right away and give as much information as possible. Pictures of the damaged tree are very helpful. If you spot an adult beetle, please take care not to handle it with bare hands! They will bite and draw blood! If you catch one, put it in a metal or glass jar/canister and put it directly in the freezer. The ALB can chew through any materials besides glass and metal.
Thank you so much for doing your part! We love our beautiful, native, mature trees and want to do everything we can to keep them healthy and safe!
All photos on this page courtesy of Beetle Busters.
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