The Boston Parks and Recreation Department has installed experimental traps at twelve locations in the Emerald Necklace in an effort to protect elm trees from destructive elm bark beetles.  The trap monitoring program, undertaken in partnership with the Friends of the Public Garden, is slated to run from March 1 to October 1.

The traps consist of 18.5"x 28" green plywood boxes mounted approximately 15 feet off the ground on trees located at least 150 feet away from any elms.  Four have been placed on Boston Common, four in the Public Garden, three in the Fenway Victory Garden, and one in Copley Square. 

The traps are designed to monitor elm bark beetles which cause damage when the larvae build “galleries” beneath the bark.  Adults pose an additional threat when they travel from sick to healthy trees carrying Dutch elm disease spores with them. 

Each trap contains a paper lining with a sticky surface that acts like old-fashioned flypaper.  The paper is infused with a pheromone lure to attract the insects. The traps contain no pesticides or harmful chemicals. 

This new approach is in line with current integrated pest management (IPM) strategies to reduce the amount of chemicals used to control harmful insect populations.  The traps will give the Parks Department and the Friends of the Public Garden important data on the elm bark beetle populations such as numbers of beetles and timing of their generational hatching.  This data will then help form a more effective and environmentally friendly management program.

The life cycle of the elm bark beetle is centered on elm trees.  Adults spend the winter living in the base and emerge in the spring when they fly to the tops of healthy elms to feed.  The larvae grow beneath the bark and emerge as adults in summer.  Emerging adults, potentially carrying spores from diseased trees, spread Dutch elm disease when they feed on healthy trees.  In the fall the insects return to the base of the tree to build their homes for the winter, creating additional opportunities for the spread of Dutch elm disease.

For more information, please call the Parks Department’s ParkLine at (617) 635-7275 or email parks@cityofboston.gov.