Beetle - Asian Longhorned
Asian Longhorned Beetle (Anoplophora glabripennis).
A new and potentially serious threat to some of North America’s most beautiful and popular trees is the Asian Longhorned Beetle (Anoplophora glabripennis). Native to parts of Asia, the beetle is believed to have arrived in North America in the wooden packing material used in cargo shipments from China. Isolated Asian Longhorned Beetle infestations have been discovered in Brooklyn and Amityville, New York, and in Chicago, Illinois. In all instances where Asian Longhorned Beetles have been found, authorities have reacted quickly to stop the infestation from spreading.
Trees favored by the Asian Longhorned Beetle are predominantly maples, but infestations have also been discovered in horsechestnuts, poplars, willows, elms, mulberries and black locusts. Currently, there is no known chemical or biological defense against the Asian Longhorned Beetle and, in North America, they have few natural predators. In all cases of infestation, the affected trees are cut down and the wood destroyed.
Female Asian Longhorned Beetle
Male Asian Longhorned Beetle
|How does it harm the tree?|
Beetle exit holes (E) and where eggs are laid (O) on a maple tree.
Sawdust from beetles chewing their way out of a tree.
The Asian longhorned beetle is extremely destructive. The damage is caused by beetle larvae which burrow deep within a tree to feed on its food and water conducting vessels. Continued feeding causes structural defects and eventually kills the life-sustaining cambial layer by girdling. Mature beetles then burrow out of the tree leaving holes the diameter of ball-point pens. Heavy Asian Longhorned Beetle infestations can kill otherwise healthy adult trees.
Mature beetles emerge from trees beginning in late May and lasting through October with a frequency peaking in July. Tree infestations can be detected by looking for tell-tail exit holes 3/8 to ¾ inches in diameter (1.5-2 cm) often in the larger branches of the crowns of infested trees. Sometimes sap can be seen oozing from the exit holes with coarse sawdust or ‘frass’ in evidence on the ground or lower branches.
|How can a homeowner control it?|
If you detect the presence of Asian Longhorned Beetles, contact local forestry officials immediately so that they can takes steps to contain the outbreak. Unfortunately, the only way currently known to combat the Asian Longhorned Beetle is to destroy the infested trees. But, while cutting down mature trees is a tragedy, it is preferable to permitting this new menace to spread.
Images & Information courtesy US Forest Service
Asian Longhorned Beetle
After the discovery in 1996 of Asian longhorned beetles (ALB, Anoplophora glabripennis) on several hardwood trees in Brooklyn, New York, the Secretary of Agriculture declared an extraordinary emergency in order to combat the infestation with regulatory and control actions. Asian Longhorned Beetles are believed to have been introduced into the United States from wood pallets and other wood packing material accompanying cargo shipments from Asia.
The beetle infestation in New York spread to Long Island, Queens, and Manhattan. In 1998, a separate introduction of the beetle was discovered on trees in the suburbs of Chicago, Illinois. Beetles were also detected in two separate New Jersey locations - in Jersey City in 2002 and in Middlesex/Union counties in 2004. In 2007, ALB was found on Staten and Prall’s Island in New York. Most recently, beetles were detected in Worcester, Massachusetts in August 2008.
In April 2008, both the Jersey City and Chicago infestations were declared eradicated. Currently, USDA-APHIS' Plant Protection and Quarantine (PPQ) is implementing quarantine and control strategies in New York, New Jersey, and Massachusetts that seek to eradicate this serious pest from the United States.
The Asian Longhorned Beetle is classified in the wood boring beetle family, Cerambycidae. Adults are 1 to 1 ½ inches in length with long antennae and are shiny black with small white markings on the body and antennae ( see Identifying the Asian Longhorned Beetle). After mating, adult females chew depressions into the bark of various hardwood tree species (see Hosts (PDF; 22 Kb) in which they lay (oviposit) their eggs.
Once the eggs hatch, small white larvae bore their way through the bark into the tree, feeding on the sensitive vascular layer beneath. The larvae continue to feed deeper into the tree's heartwood forming tunnels, or galleries, in the trunk and branches. This damage weakens the integrity of the tree and will eventually kill it if the infestation is severe enough.
Over the course of a year, a larva will mature and then pupate near the surface, under the bark. From the pupa, an adult beetle emerges, chewing its way out of the tree; forming characteristic round holes approximately 3/8ths of an inch in diameter. Many of these holes will appear on a heavily infested tree frequently accompanied by frass (sawdust) and sap oozing from the holes. The emergence of beetles typically takes place from June through October with adults then flying in search of mates and new egg-laying sites to complete their life cycle.
The tree species preferred as hosts by the Asian Longhorned Beetle are hardwoods including several maple species (Norway, sugar, silver, and red maple), box elder, horsechestnut, buckeye, elm, London plane, birch, and willow.
Host List (PDF; 22 Kb)
The Asian Longhorned Beetle's native range includes China and Korea. Information on the distribution of the current infestations in New York, New Jersey, and Massachusetts can be found in the Maps section.