Gypsy moth treatment methods

April 27, 2003|by ANDREW SCHOTZ

The two insecticides most commonly used to destroy gypsy moths are Bacillus thuringiensis, or Bt, and diflubenzuron, which is known as Dimilin.

Bt, which is bacteria-based, is used near water. It's a stomach poison that stops gypsy moths from feeding after they ingest it.

Dimilin, a chemical insect growth regulator, is used away from water. It's a chitin inhibitor that prevents insects from molting from one stage to the next.

Some national parks use an insecticide called Gypchek. It's a powder made up of gypsy moth caterpillars killed by the naturally-occurring nucleopolyhedrosis virus, or NPV.


West Virginia is using another technique, too.

In its southern counties, the state is spraying a pheromone flake that simulates the scent of a female gypsy moth. As the air is saturated by the female smell, male moths can't pick them out, which disrupts the mating process.

This technique is part of the National Gypsy Moth Slow the Spread Project, which runs from Wisconsin and the Upper Peninsula of Michigan to North Carolina.

Bob Tichenor, the chief of forest pest management for the Maryland Department of Agriculture, said pheromone flakes work best where the gypsy moth population is "low and scattered." Maryland is well past that stage, he said.

- Andrew Schotz

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