Metro Atlanta Beekeepers Association

In Worcester, Massachusetts, a toxic dilemma: Beekeepers wary of pesticides to fight beetle infestation

By Beth Daley. Boston Globe.  September 16, 2009

 A beetle infestation in Worcester has placed scientists amid an ecological dilemma: Can they save the trees without harming the bees?

 Tomorrow, federal officials will begin injecting hundreds of beetle-threatened trees and nearby soil with imidacloprid, a widely used agricultural pesticide that is known to be toxic to bees and has been linked to a worldwide die-off of honey bees. Federal and state scientists are trying to eradicate the invasive Asian longhorned beetle (Anoplophora glabripennis) from the Worcester area before it can spread to the beloved hardwood forests of northern New England. 

 In advance of the pesticide pilot program, some beekeepers are moving their hives out of the area. But they are even more worried about a plan to inject soil and trees in a fourteen-square-mile swath next spring with three times the amount of pesticide per acre the United States Environmental Protection Agency (EPA) now says should be used. That plan is to be considered today by a subcommittee of the state Pesticide Board, which regulates pesticide use.

 Beekeepers say large amounts of the chemical, combined with the soil injection method, could result in more than just trees taking up the pesticide; it could expose bees to contaminated nectar and pollen of other plants. The chemical could also seep into water bodies and harm other living things, they fear.

 “We understand the beetle needs to be controlled and that chemicals are going to be part of the solution . . . but we are also worried that the [soil injection] in particular will have an effect on pets, squirrels, other living creatures,’’ said Mary Duane, president of the Worcester County Beekeepers Association. “It would be safer to inject the tree. Yet that also has us concerned.’’

 United States Department of Agriculture (USDA) officials, who are proposing the spring pesticide application, say they have few other options to halt the pest. Already, more than 20,000 infested trees have been cut down.

 Imidacloprid is the most effective tool to fight the insect, and the increased amount of pesticide per acre is needed to protect the large number of trees in dense woodlots, the officials say. Similar treatments as the one proposed in Worcester have successfully mitigated infestations in New York and New Jersey.

Soil injection “is more cost effective than trunk injection,’’ said Christine Markham, director of the Asian Longhorned Beetle National Program for the USDA. “We will be able to treat more trees.’’

Asian longhorned beetles have no known predators in the United States and attack many kinds of hardwood trees, from maple to birch. First discovered in 1996 in Brooklyn, they have shown up in other parts of New York, as well as in Chicago and New Jersey. The Department of Agriculture estimates the beetle has the potential to cause $41 billion worth of damage to the nation’s lumber, maple syrup, nursery, and tourism industry.

 The shiny black bug has irregular white spots, and has antennae at least as long as its one to one and one-half inch body. It kills a tree by essentially cutting off its circulation: The female beetle lays eggs in the bark and worm-like larvae then bore into the healthy tree, feeding on tissue during the fall and winter before emerging through bark holes. Tomorrow, state environmental officials are examining trees in Boston’s Public Garden as a part of an outreach campaign to encourage people to examine trees for early signs of infestation.

But as concern grows over the beetles, so do worldwide worries over imidacloprid, which is widely used in this country to control a myriad of nuisances, such as potato pests, fleas, and lawn grubs. It and similar chemicals are not allowed for certain uses in Germany and France. Beekeepers and some researchers have implicated the chemical in colony collapse disorder, the mysterious die-off of honey bees.

“It’s indisputable it is getting in the pollen and nectar [of plants] at parts per billion, and independent labs show effects on bees at those levels,’’ said Jennifer Sass, a toxicologist and senior scientist at the Natural Resources Defense Council. The council and other advocacy groups have been petitioning the EPA to study the long-term effects of the pesticide more rigorously. Locally, the Toxics Action Center and a national coalition, SafeLawns.org, are protesting its soil application in Worcester.

 Jack Boyne, an entomologist and spokesman for Bayer CropScience, which makes imidacloprid, said that like many pesticides, imidacloprid is toxic to bees, but that toxicity can be avoided when it is used according to label guidelines. He said the chemical is not linked in any way to colony collapse disorder.

 City Manager Michael O’Brien said Worcester has been devastated by the infestation. “In order to preserve as much of the urban forest as possible, we want to pursue these [chemical] alternatives,’’ he said, but only if they meet approval by state and federal environmental officials.

 Even as the chemical is used, beekeepers in the Worcester area will be helping to figure out just how toxic the treated trees could become to bees. They, and the USDA bee lab, have placed twenty-five hives in the quarantined area and twenty-five outside of it in Framingham, to see how much of the chemical appears in hives and the bees themselves over the next three years.

 “This will be a good national experiment to see if it is affecting the beehives,’’ said Kenneth Warchol of the Worcester Beekeepers Association, who is helping to run the study.