By Rhonda Santos
As a reader of Arbor Age, you likely already know about the Asian longhorned beetle or ALB (Anoplophora glabripennis) and its impact on trees. What you likely haven’t heard enough about is the effort to rid ourselves of this invasive tree pest.
This past May, the U.S. Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS), together with its partners, announced the beetle has been effectively eradicated from an area in Boston. The beetle was discovered in Boston in July 2010 and 10 square miles were regulated in Norfolk and Suffolk Counties. At just under four years, the announcement marks the shortest eradication timeframe yet.
APHIS and its partners undertake eradication by imposing quarantines or regulations, conducting regulatory inspections, surveying host trees by using ground and aerial visual survey methods, removing infested and high-risk host trees, and chemically treating un-infested host trees. An area can be declared free of the beetle after all the infested trees are eliminated and multiple surveys are negative for active signs of the beetle activity or the presence of the beetle itself.
The short time taken to eradicate the pest in Boston is a testament to early detection lessening the impact to an affected community. The eradication program removed six infested trees from one property and conducted multiple inspection surveys of more than 90,000 host trees. In May 2013, the third and final cycle of chemical treatment applications were completed on 2,000 host trees. The eradication in Boston reduces the areas regulated for ALB in Massachusetts from 120 to 110 square miles. Regulations remain in place for areas within Worcester County in central Massachusetts.
Unfortunately, this past March, 28 square miles were added to the ALB regulated area on Long Island, New York, affecting areas within Babylon Township. As a result, the total regulated area for ALB on Long Island has expanded from 23 square miles to 51 square miles, with a total of 137 square miles under regulation in New York. Regulations remain in place for the boroughs of Brooklyn and Queens. While this discovery is disheartening, the goal remains to eradicate the beetle while trying to saving as many trees as possible.
Preventing the spread of ALB is a top priority for the USDA. If ALB were to become established in the United States, it could have a severe impact on the timber, maple syrup, tree nursery, and tourism industries, as well as on the environment. In addition, public spaces, yards, and neighborhoods would take decades to recover.
Unfortunately, all states are at risk as all states have trees the beetle can attack and in which it can complete its life cycle. However, the states that are already fighting an ALB infestation, and those states boarding an infestation, are at a higher risk as the beetle may have been unknowingly moved inside tree debris or firewood — thus starting an infestation in a new area. These states are more likely to be impacted by ALB because and ALB infestation is already so close.
The beetle has been detected in five U.S. states — New York (1996), Illinois (1998), New Jersey (2002), Massachusetts (2008), and Ohio (2011). ALB was successfully eradicated from Illinois in 2008, from New Jersey in 2013, from the New York City boroughs of Manhattan and Staten Island in 2013, and now from the area within Boston.
Surveying or inspecting trees means looking at the host trees the beetle attacks for the beetle itself or signs of damage caused by it. The most concerning signs are dime-sized exit holes, roughly 1/4 inch or larger and perfectly round. Look also for round or oval shallow scars in the bark where the females chew oviposition (egg-laying) sites. What is most striking about these sites is that on their outer edges, you can usually see the insect’s mandible chew marks on the bark. Look also for frass or sawdust-like material (beetle excrement) on the ground at the base of the tree or at the crotches of branches. Dead branches or canopy dieback can indicate something is wrong. Finally, look for the beetle itself on the tree trunk, branches, on the ground, and on nearby surfaces. Although the beetle may look menacing, it is harmless to people. The ALB is generally 1 to 1.5 inches in length, have six legs, and a shiny, jet-black body with random white spots.
The most important thing you can do is to check trees regularly for signs of the beetle and encourage homeowners to do so as well. Early detection is crucial. It can mean the difference between the six infested trees lost in Boston verses the situation in Worcester County, Mass., where an infestation went undetected for at least a decade, and after the last 5 years of eradication efforts the infestation has resulted in the loss of nearly 34,000 trees and has impacted countless residents.
If you can only check trees once a year, then the best time of year to do this is in the month of August, as that is when the number of beetles will peak and you are most likely to see an adult insect, as well as seeing the damage it causes on the tree itself.
USDA recognizes the month of August as “Tree Check Month” by undertaking strategies to raise awareness about the pest and encourage the public to report any suspicions. The best line of defense against the insect is people who take the time to check their trees for the beetle and any signs of damage it causes, even if you only have 10 minutes to spare. The Tree Check Month campaign, which runs during the summer months, asks people to help save trees by:
Conducting an annual tree check
Reporting beetles or signs of damage
Allowing officials access to survey trees
Purchasing firewood where it will be burned
Diversify the tree plantings
While the eradications of ALB are a victory for all of us, we all still need to stay vigilant and inspect trees regularly for signs of infestation, especially since trees in all states are at risk. One great resource for arborists is a photo-rich publication titled “Asian Longhorned Beetle and its Host Trees,” which was published by the USDA’s U.S. Forest Service ([ital>http://na.fs.fed.us/pubs/alb/alb-and-host-trees-09-12-2012-screen.pdf<ital]). It shows the host trees, as well as damage caused by the insect.
The sooner an infestation is reported, the sooner efforts can be made to quickly contain and isolate an area from future destruction. ALB eradication programs are cooperative programs and APHIS works with several different federal agencies, as well as different partnering organizations in each affected state. For more information or to report, please visit the APHIS website for Asian Longhorned Beetle or www.asianlonghornedbeetle.com, or call 866-702-9938 to be forwarded to your state plant health director’s office.
Rhonda Santos is public information officer, USDA APHIS Asian Longhorned Beetle Eradication Program.