Fighting the Asian Longhorn Beetle: A 50 million dollar battle
Posted by Tyler
The USDA first confirmed the presence of the Asian Longhorned Beetle in Worcester in early August of 2008. The combined state and federal government’s removal effort is still ongoing, and has — at last count — cost approximately 50 million dollars. This expense – large as it is – constitutes a reliable indicator of just how great a threat the Asian Longhorned Beetle poses to local forests. However, despite the best efforts of the Massachusetts Department of Agriculture, the pest continues to spread across the state. As evidenced by the fact that recently (August of 2010), Asian Longhorned Beetles were confirmed to have entered Boston.
The Asian Longhorned Beetle nests in the living tissue of many native trees – Maples, Willows, Elms, Birches, and Horsechestnuts to name a few – making hollows beneath the bark that can eventually prove fatal for the tree. A full-fledged invasion of Massachusetts’ forests could therefore prove to be extremely bad for the health of local forests, as well as to the survival of the industries that depend on their health for revenue.
Currently, infestations of Asian Longhorned Beetles are dealt with with a combination of strict quarantine measures in infested areas, pesticides containing the chemical imidacloprid, and the removal and thorough destruction of infested trees. The USDA has urged Massachusetts residents to keep a careful eye out for Asian Longhorned Beetles and to continue to honor the policy of not removing wood from the quarantine areas.
As is true for most management efforts, locating members of the target invasive species before they are able to breed in an area is crucial to reducing their numbers. Unfortunately, Asian Longhorned Beetles breed quickly, with females laying their eggs in pits they chew out in the bark of infected trees. Once the eggs mature into larvae, they burrow their way into the living tissue of the tree and enter the pupal stage. Adult beetles emerge the spring following their hatching by tunneling straight outwards through the bark of the tree, creating large holes as they exit their nurseries. Infected trees are easily identified by the presence of sawdust like ‘frass’ littering the bark and the ground around them. This sawdust is generated by the actions of the beetles within the still living tree.
Once detected, the USDA recommends a specific strategy to control the spread and reproduction of the invading beetles. After quarantining the area surrounding the infected trees, all potential host trees within half a mile of the original detection are treated with pesticides. Depending on the severity of the infestation, and on the specific qualities of the forest in question, infected trees may be removed entirely rather than simply sprayed. In this case a replanting treatment follows the eradication of the beetle from the area.
This method of controlling the spread of the Asian Longhorned Beetle has shown itself to be effective –so far — at treating beetle invasions. An Asian Longhorned Beetle infestation in Chicago was effectively removed this way. Hopefully the infestation in Massachusetts will likewise be eliminated. In the meantime, both the state and federal governments urge citizens to continue to report beetle sightings.