Asian Longhorned Beetle

Asian longhorned beetle

Figure 1.  The Asian longhorned beetle is a large white-spotted beetle with long antennae.  Photo courtesy of Melody Keena, USDA Forest Service, Bugwood.org.

General Information

The Asian longhorned beetle (Anoplophora glabripennis Motschulsky (Coleoptera:  Cerambycidae)), a native of eastern Asia, poses a new threat to Arkansas’ forests (Fig. 1).  It is thought that the beetle was introduced to New York City in solid wood packing materials (Fig. 2) in the 1980’s because it was first discovered in North America in Brooklyn, New York, in 1996.  From there it has spread steadily westward and northward.  This pest has since distributed itself from Boston, MA, to Ohio and north into Canada.  Additional beetles have been found around Chicago, IL; Sacramento, CA; Los Angeles, CA; Mobile, AL; and Fort Lauderdale, FL; indicating that the beetle has been introduced to more than one location.  Fortunately, none of these introductions has resulted in established

Solid wood packing material

Figure 2.  Solid wood packing material has been the primary vector for moving Asian longhorned beetle to North America.  Photo courtesy of Larry R. Barber, USDA Forest Service, Bugwood.org.

populations.  At present, the closest known established population to Arkansas is in Ohio.  Presence of the beetle at ports of entry scattered around the US and at some inland sites together with the fact that many shipments into coastal ports of entry are then shipped to Arkansas packed in solid wood materials, indicates a great potential for the beetle to be introduced into Arkansas, as well.

Asian longhorned beetles (ALB) attack many of our native hardwoods.  This includes maples, elms, willows, birches, poplars, ashes, and hackberries.  All of these are components of the hardwood timber harvest in Arkansas, and several of them are important species to wildlife.  If the beetle becomes established in Arkansas, it will alter our forests, impact our wildlife, and impact the economic value of many landowners’ forest investments.  American Nurseryman Magazine published an excellent article, A Killer in Black and White, discussing ALB in the Northeast.

Like many of our introduced insect pests, ALB arrived in solid wood packing materials.  This gives us some clues indicating how the beetle might be spread to Arkansas.  Packing crates from Asia are shipped to coastal US ports and then into Arkansas.  Lumber and raw logs are also shipped into Arkansas from parts of the US potentially infested with ALB.  Because of the potential to spread ALB by moving wood, quarantine zones have been established around known infestations.  Arkansas is not in one of these quarantine zones yet, but looking at the list of materials that cannot be exported from quarantine zones will give us some idea of how to avoid bringing this pest to Arkansas.  Here is a link to a description of Ohio’s quarantine to give you an idea of what is involved.

Ohio Regulated Area:  Asian Longhorned Beetle

 

Identification

Cottonwood Borer and ALB

Figure 3. The native cottonwood borer (top) is often mistaken for the ALB (middle and bottom) in the South. Photo courtesy of Gerald J. Lenhard, Louisiana State University, Bugwood.org.

The ALB is a large insect, ranging from 1 to 1.5 inches (25 to 38 mm) long.  It has antennae that, as the name implies, are very long – up to 4 inches (100 mm).  The beetles are glossy black with scattered white spots that give them the alternate name “starry sky.”

 

Gerald J. Lenhard, Louisiana State University, Bugwood.org – See more at: http://www.forestryimages.org/browse/detail.cfm?imgnum=0014056#sthash.N9pWWmzg.dpuf

There are several native longhorned beetles that could be confused with the ALB.  In the South, the native cottonwood borer (Fig. 3) is most commonly mistaken for ALB.  Since ALB has not been found in the south, information on look-alike beetles for this area has not been developed.  The following information has been developed for parts of the US where ALB has been found.

Asian Longhorned Beetle Look-alikes

Have you seen the Asian Longhorned Beetle?

How to Recognize – Asian Longhorned Beetle

University of Vermont ALB Identification Page

Asian longhorned beetle

Figure 4.  The Asian longhorned beetle has distinct black and white banded antennae.  Photo courtesy of Melody Keena, USDA Forest Service, Bugwood.org.

The primary characteristics to look for are very long black and white banded antennae of the males (Fig. 4), a shiny black body with bold white spots (Fig. 5), and bluish tinged legs

Asian longhorned beetle

Figure 5.  The Asian longhorned beetle has a shiny black body with bold white spots.  Photo courtesy of Michael Bohne, Bugwood.org.

(Fig. 6).  Similar beetles have long antennae that are NOT black and white banded.  Other similar beetles have small white spots or dull black

Asian longhorned beetle

Figure 6.  The Asian longhorned beetle has bluish tinged legs.  Photo courtesy of Kenneth R. Law, USDA APHIS PPQ, Bugwood.org.

bodies; but they don’t have the combination of antennae and color pattern that the ALB has.

 

Biology

Asian longhorned beetles breed throughout the summer months.  The male and female beetles stay together, with the male guarding the female as she prepares sites to lay eggs (Fig. 7).  The female beetle chews 3/4-inch (18 mm) craters of various shapes into the bark of the host tree (Fig. 8).  The craters extend through the bark down to the wood.  The

Asian longhorned beetle breeding pair

Figure 7.  After breeding, the male Asian longhorned beetle guards the female beetle until she completes laying eggs.  Photo courtesy of Karen Snover-Clift, Cornell University, Bugwood.org.

female lays one egg in each crater at the interface of the cambium and wood.  ALB’s can lay up to 90 eggs.

Asian longhorned beetle incubation crater

Figure 8.  Female Asian longhorned beetles chew pits into the bark of trees.  Eggs are laid singly on the fresh cambium at the bottom of the pit.  Photo courtesy of Pennsylvania Department of Conservation and Natural Resources – Forestry Archive, Bugwood.org.

Once the larvae hatches, it feeds on the cambium of the tree around the oviposition site.  Eventually, the larvae burrows into the wood of the tree where they continue to feed on the wood until they mature.  Larvae may be up to 2 inches (50 mm) long at maturity (Fig. 9).  Larvae spend

Asian longhorned beetle larvae

Figure 9.  Asian longhorned beetle larvae can get up to about 2 inches (50 mm) long before they pupate.  Photo courtesy of Steven Katovich, USDA Forest Service, Bugwood.org.

the winter in the trunk of the tree.  In the spring, larvae resume growth then pupate for about 20 days (Fig. 10).  After pupation the 1

Asian longhorned beele pupa

Figure 10.  Asian longhorned beetle larvae pupate in a chamber within a tree trunk for about 20 days.  Photo courtesy of Pennsylvania Department of Conservation and Natural Resources – Forestry Archive, Bugwood.org.

to 1.5 inch (25 to 38 mm) adults bore to the surface of the tree and exit, leaving a half-inch (12 mm) diameter hole (Fig. 11).  The complete life cycle takes 12 to 18 months.

 

Asian longhorned beetle exit hole

Figure 11.  Exit holes made by the Asian longhorned beetle are up to about ½ inch (13 mm) diameter.  Photo courtesy of Joe Boggs, Ohio State University, Bugwood.org.

Distribution and Hosts

The ALB is a native of northeast Asia.  This pest was discovered in North America in 1996 and has been found in several European countries.  In Asia, trees typically infested include maples, poplars, willows and elms.  Among North America’s native species, ALB will also attack buckeye, birch, ash, sycamore, and cherries.  Alders, beeches, and hornbeams; in addition to the genera listed for North America; have been attacked in Europe.  Unlike many pests, ALB will attack healthy trees.

Evidence of ALB was first observed in North America in Brooklyn, New York.  This finding prompted a search that revealed ALB infestations in several boroughs of New York and several cities adjacent to New York City.  Two years later an infestation was identified in Chicago, IL, then in 2002 another infestation was identified in New Jersey.  It has subsequently been found in Boston, MA.  Since that time, beetles have been found in warehouses in 15 states and five Canadian provinces.

ALB probably came to North America in solid wood packing material.  Since the larvae bore into wood, they probably were present in packing crate lumber that was brought into U.S. ports.  Arkansas ports also receive wooden crates from abroad, so we are at risk, too.

 

Signs and Symptoms

Asian longhorned beetle cambium mining

Figure 12.  After Asian longhorned beetle eggs hatch, the larvae mine the cambium immediately under the bark, then bore into the wood.  Photo courtesy of Melody Keena, USDA Forest Service, Bugwood.org.

ALB larvae damage trees in two ways.  First, the young larvae mine the cambium around the site of oviposition (Fig. 12).  A heavy infestation can kill limbs in the host tree.  As the larvae grow, they bore into the wood and weaken the structure of the tree, making it more susceptible to storm damage.  Repeated infestation can seriously weaken a tree, resulting in tree death.

Visible symptoms include dying branches in the crown (Fig. 13), large exit holes in limbs (Fig. 14), and “sawdust” on the ground around a tree.  If you see limbs dying in a tree, attempt to examine the tree to determine the cause.  You should be able to see the large exit holes, up to 3/4-inch (19 mm) diameter, if ALB’s are causing the damage.  A pair of binoculars may

Crown dieback resulting from Asian longhorned beetle infestation

Figure 13.  Dying branches in a tree crown are one of the indications of Asian longhorned beetle infestation.  If you see these symptoms, examine the tree carefully.  Photo courtesy of Dennis Haugen, USDA Forest Service, Bugwood.org.

Asian longhorned beetle exit holes

Figure 14.  Egg craters and large diameter exit holes often are signs of Asian longhorned beetle infestation.  Photo courtesy of Pennsylvania Department of Conservation and Natural Resources – Forestry Archive, Bugwood.org.

be helpful.  Note that many types of wood-boring pests can generate “sawdust” similar to that generated by the ALB.  Examine the tree more closely, especially upper branches, to identify the large exit holes created by the ALB.

Unfortunately, once a tree is infested with ALB, the only treatment option is to remove the tree to reduce spread of the pest.  Treatment with insecticides will not kill all of the larvae in the tree.  The infested tree will continue to pose a risk to the trees around it.  Non-infested trees in the vicinity of infested trees can be treated with insecticides to during spring to reduce the risk of infestation while adult ALB are actively flying.

 

Stop the Spread

There are several things foresters and landowners can do to slow or stop the spread of the Asian longhorned beetle.  First, educate yourself about the ALB.  Learn to recognize the symptoms displayed by infested trees and learn how the pest is moved by people.  Second, be careful about moving firewood.  Firewood transport is one of the prime movers of ALB.  Never haul firewood out of an ALB quarantine area.  Third, if you buy or sell hardwood logs, follow ALB quarantine regulations for handling and processing those logs.

Let’s work together to keep the Asian longhorned beetle out of Arkansas.

 

Resources

Additional resources to learn about Asian longhorned beetle are available in our Resources section.