The U.S. Forest Service is scheduled to deliver the third and final aerial application over the West Lafayette campus on Thursday (June 26).
The previous two applications involved Btk, a bacterium that occurs naturally in the soil. This third application involves spraying pheromone flakes, with the goal of disrupting the mating process of these invasive pests, which threaten Purdue's tree population.
This third application will once again involve the use of a low-flying plane to distribute the pheromone flakes. The flakes are very small and not harmful to humans or animals. The application is expected to take place at roughly 7 a.m. and last an hour to an hour and a half. If weather conditions are inadequate, the application could be postponed.
The gypsy moth is one of North America's most devastating forest pests, which was first accidentally introduced to the United States near Boston in 1869 by an immigrant artist turned astronomer who dabbled as an amateur entomologist. The insect has slowly spread throughout the Northeast and into parts of the upper Midwest and Great Lakes states, including Indiana.
"You can liken the spread of gypsy moth to that of a slow-burning forest fire," says Purdue entomologist Matthew Ginzel. "It's been in the U.S. for almost 150 years and has been inching westward. This eradication effort is like stomping out a cinder from this large fire that has landed in West Lafayette. In this way, we can slow the spread of gypsy moth. Larvae were discovered last summer on campus, and we're mandated to take action."
Gypsy moth larvae are small and spread by the wind or transport of wood. The gypsy moth caterpillar can grow up to 4 inches long and consume up to 11 square feet of foliage from early May until June. The moths have a large appetite for oak trees but also feed on numerous others species and, when abundant, can defoliate and kill trees. Additionally, the rain of caterpillars and their excrement from treetops can cause rashes or allergies.
"We've been working on gypsy moths for about 20 years in Indiana," says Scott Kinzie, nursery inspector and compliance officer at the Indiana Department of Natural Resources. "We're trying to keep it in the northern part of the state, basically in a line from Jay County running all the way up to Newton County. There is so much of it there we won't eradicate it, but we're trying to keep it from spreading further south. Hopefully, this will take care of it and will be the only time we will be treating the Purdue area."
Those with questions can call DNR toll-free at (866) NO-EXOTIC (663-9684).