Invasive Asian Longhorned Beetle Thrive on Red Maple

Adult Asian longhorned beetle (ALB) shown on maple, chewing an egg site (image from aphis.usda.gov) Federal researchers have taken a step forward in the battle against the invasive Asian longhorned beetle (ALB). A recently released U.S. Forest Service study revealed the tree-killing ALB to be more than four times as likely to successfully develop into an adult when feeding on red maple versus other species of maple in Massachusetts.

The study, published in the scientific journal, Insects, could help prioritize ALB survey strategies in other states.  “In these forests, ALB attacked red maple at high rates and adult beetles emerged far more often from these trees than other maple species present,” said Forest Service entomologist Kevin Dodds, the lead author of the study. “Unfortunately, red maple is geographically widespread and found in many environments, providing ALB a pathway into new areas.”

A typical round exit hole of the adult Asian Longhorned Beetle (image from extension.umass.edu).

The researchers looked at two forested areas comprised of multiple hardwood species within the Worcester, Mass. ALB quarantine zone. While ALB egg sites were found in red, Norway, and sugar maple in the stands studied, fully grown beetles chewed their way out of 15% of the Norway and just 12% of the sugar maple trees. Nearly 60% of the red maple trees examined produced adult beetles.

The results from this study add further evidence to a 2011 Forest Service and Harvard University study that suggested ALB more often attacked red maple. That work assisted in prioritizing some survey and trapping resources in Massachusetts.

Fortunately, New Jersey and Illinois have eradicated ALB infestations. Eradication activities continue in Massachusetts, New York and Ohio. All known host tree species are still at risk of being attacked by the beetle and having adults emerge. Potential hosts include: ash, birch, elm, goldenrain tree, hackberry, horse chestnut, katsura, London plane tree, maple, mimosa, mountain ash, poplar and willow.

A maple tree with visible Asian Longhorned Beetle Damage (image from bugwood.org).

USDA’s Animal and Plant Health Inspection Service (APHIS) manages infestations nationally and was involved in the study. “Currently, our ALB eradication efforts include visual surveys of all ALB host trees,“ said Josie Ryan, national operations manager of APHIS’ ALB cooperative eradication program. “However, the results from the study may allow us to look at ways our visual surveys could be altered to provide a greater use of resources.”

For more information regarding the complete study, “Colonization of Three Maple Species by Asian Longhorned Beetle, Anoplophora glabripennis, in Two Mixed-Hardwood Forest Stands,” visit: http://www.mdpi.com/2075-4450/5/1/105.