Last moth treatment complete
- Published: July 1, 2010
The crop duster that flew over the village several times last week wasn’t aiming for crops, but rather the furry brown and white gypsy moths that have been dining voraciously on the area’s oak trees. This week the moths are cocooning peacefully in their tiny pupal cases, but in July, those benign looking bugs will be drying their newly formed wings and taking flight to mate and breed a whole new generation of leaf-eating machines.
The Ohio Department of Agriculture has been working to suppress the invasive gypsy moth population since 1989, when the bugs spread into the state from New York and Michigan. While the exact population of the moths in the area isn’t yet known, according to ODA moth treatment coordinator David Adkins, Greene County is one of 12 counties in Ohio which have reached an intermediate infestation level labeled as “Slow the Spread” (STS), meaning the population is being treated but has not yet reached a peak saturation level. The two treatment areas in the county are located directly to the east and west of Yellow Springs.
The east block is a 1,800-acre rectangle that covers all of John Bryan State Park. The west block is a 1,400-acre rectangle that runs just north of Hyde Road from the west side of East Enon Road out to State Route 343. According to Adkins, the areas received one STS treatment in May, using a bio-insecticide known as gypchek, and a soil bacteria known as Btk, both of which interfere with the caterpillar feeding cycle and serve to reduce its population. Concentrated Btk and gypchek can cause eye and skin irritation, but neither is otherwise harmful to humans, pets or birds, according to their manufacturing labels. The second treatment, which occurred last week, included a solution of SPLAT, concentrated at 6 grams per acre and used to disrupt the mating cycle of the moths. SPLAT contains a synthetic hormone, with active ingredient 7,8-Epoxy-2-methyloctadecane, and comes with a warning against ingesting the concentrated chemical.
While the treatment of STS zones is paid for by the ODA and the U.S. Forest Service, the treatment for more densely infested areas must be requested by private property owners, who are required to pay for 50 percent of the treatment cost, Adkins said.
According to Adkins, the Yellow Springs area is susceptible because of its densely foliated areas in which many campers and visitors unknowingly bring gypsy moth larvae in on fire wood, campers and other equipment.
When left unchecked, gypsy moths can cause extreme defoliation of oaks and the 300 other species of deciduous and coniferous trees they eat. According to the ODA Web site, at peak infestation, one acre can contain 250 egg masses, each with up to 1,000 larvae, which when mature can consume 250,000 square feet of foliage per acre in one day. Defoliated trees can die after several years without their leaves.
Next year, the fourth year of gypsy moth population testing, the ODA should have a better idea of the infestation level in this area, Adkins said. But the treatments are finished for this year, and the moths will spend the next month mating as quickly as they can before they die at the end of the summer. Their offspring will be looking at the juicy leaves in this area to fill their hungry bellies next spring, and the health of the area’s trees may depend on their numbers.
More information on the gypsy moths and the ODA’s program to suppress them can be found at http://www.agri.ohio.gov/divs/plant/gypsy/gypsy-index.aspx .