Asian Longhorned Beetle: The 2008 Invasion

The first recorded find of the Asian longhorned beetle (ALB) (Anoplophora glabripennis) in Massachusetts occurred on August 2, 2008. It was reported to the Northeast Office of the USDA APHIS PPQ* in Connecticut late on Friday August 1 by an observant local resident. A site inspection was performed by PPQ and the Massachusetts Department of Agricultural Resources (MDAR) the following day. Samples of adult beetles collected from the site were sent to the Systematic Entomology Lab (SEL) in Beltsville, MD and on Monday, August 4 the insect was officially verified as being ALB by the authority at SEL.

The initial find was centered in the northern section of Worcester known as Greendale. ALB was soon found near the town line of Holden and also with Shrewsbury. For the first two weeks, ALB was only found in Worcester but four other towns became part of the Regulated Area. ALB is a weak flier and generally does not venture far from the tree that it emerges from as an adult. In fact, most female beetles will lay their eggs within the same tree or one in close proximity to the tree that they emerged from. Studies have shown that under optimal conditions female ALB can go as far as 1.5 miles but rarely do. Therefore, when a tree is infested with ALB, a 1.5-mile radius is drawn around that tree on the map and that area then becomes regulated. The entire regulated area is the accumulation of all the 1.5-mile radius circles and the margins of the regulated site are often extended out to the nearest major roadway on the map. The official Regulated Area as of September 22, 2008 for the Worcester find of ALB is approximately 33 sq. miles, but it is important to note that the beetle has not (yet, at least) been found consistently throughout that area; it is, however, the area where the most intense survey work will continue.

To date, a little more than 1,000 trees have been found to be infested out of 8,100 trees inspected thus far, which means 12.3% of the trees inspected so far are now marked for removal. However, the survey work is continuing and this number will most likely change. The original thought was that not only would infested trees be removed, but all susceptible tree species within a 1/8 to 1/4 mile radius around each infested tree would also be removed. Now, the City of Worcester and the USDA have agreed to only remove those trees that present positive finds of the beetle. Susceptible neighboring trees within close proximity to infested trees will most likely be treated with an insecticide as prevention. This will greatly reduce the number of trees being removed. Survey work, tree removal, and the replanting of new non-susceptible trees will incur no cost to the homeowner.

Natural wood material (twigs, branches, logs, etc.) and susceptible deciduous plants cannot be moved out of the Regulated Area. Mulch can be moved if every piece of wood material making up the mulch is ‘less than 1.0 inch in two dimensions’. Firewood cannot be moved out of the Regulated Area no matter what the tree species. The City of Worcester has established drop-off sites for local residents for wood waste, such as branches, etc., although, homeowners are encouraged to not prune or cut down trees at this time. All commercial Green Industry companies affected by the regulations should have been contacted already by APHIS and have most likely attended ‘Compliance Training’, which allows the companies to perform certain work within the Regulated Area. Private companies cannot, at this time, sell any tree services to homeowners within the Regulated Area that are connected to ALB (e.g. spraying, tree injection, tree pruning or removal).

The approach to the ALB situation in Worcester is ‘Eradication’, which is to attempt to identify every individual tree that is currently infested and then remove and destroy it, thus eliminating the problem. Once the survey work is complete, A Decision about the exact plan for this work will be MADE. Removal will begin sometime in November just after a deep frost.

The Worcester finding of ALB represents a very serious situation for the residential street trees and those in private yards and on the grounds of businesses. Right now, it is estimated that the survey work, eradication efforts, and insecticide treatments will initially cost about $24 million in Worcester. Potentially more important, however, is that this finding of ALB represents the first time that this devastating pest has been found so close to the forest. Maples appear to be the preferred host for ALB in North America and this fact alone makes it a very unwanted pest in New England with the sugar maple being of most concern. Should ALB become established here, it could forever change the make up of the New England forest.