The gypsy moth (Lymantria dispar) was one of the first invasive species to damage trees in the United States. Released by accident in Massachusetts in 1869, the moths’ migration westward was slow because the females do not fly. However, the gypsy moth has been established in Ohio for a number of years.
The adult moths are of little consequence, but the caterpillars are voracious leaf feeders. Large populations can defoliate trees causing damage to tree health and disruption to area residents. Successive years of defoliation can kill trees.
This invasive pest is managed by the Ohio Department of Agriculture. The state sets gypsy moth detection traps around Ohio each year to monitor population data. There are a variety of natural factors that control moth populations, but when population levels exceed a tolerable threshold, the state intervenes with population suppression techniques to prevent canopy devastation.
Recent trap data suggests that parts of Central Ohio, including the Upper Arlington area, are due for intervention in 2020 to prevent a population peak that could cause widespread damage.
Gypsy moths typically hatch mid-spring, and the state has announced plans to use two products during late spring and early summer:
- Early May: Gypchek – Gypchek is a biological control made of nucleopolyhedrosis virus, a virus that weakens and kills young gypsy moth caterpillars. A second application may occur approximately one week after the first.
- June: Splat GM Organic – this is a biodegradable lure that disrupts adult gypsy moth mating. The product mimics the scent of gypsy moth pheromones, the fragrance used by female moths to attract males. Humans can’t detect these fragrances, but by dropping Splat GM Organic over the area (at a rate of less than one cup per acre) males become confused and are much less likely to find mates, reducing reproduction rates.
Both products are targeted, state-of-the-art treatment methods with no harmful collateral damage to people, property, animals or other insects such as honeybees. The products are applied by small, bright yellow airplanes that fly at relatively low heights over UA for brief periods.