Mount Vernon to be Sprayed for Gypsy Moths

Suppression effort to target south side for invasive insects this spring

MOUNT VERNON, Feb. 24, 2022 – A small swath of the City of Mount Vernon will soon be targeted in a state effort to suppress the spread of invasive gypsy moths, the Ohio Department of Agriculture (ODA) has announced.

Nearly 4,000 acres, from just north of Pine Street extending southeast in lines parallel to Martinsburg and Newark Roads to south of the Irish Hills Golf Course, including most of Mount Vernon Nazarene University, will be sprayed with insecticide from the air in May. The ODA has determined that there is a growing population of gypsy moths in this area and that a control treatment is needed to prevent an infestation.

Gypsy moths (Lymantria dispar) are invasive insects that can attack more than 300 species of trees and shrubs, with oak being the preferred species, although in this region they’re also attracted to other nut trees such as walnut as well as fruit trees. As caterpillars, the insects feed heavily on a tree’s leaves, limiting the tree’s ability to photosynthesize. Their nests are familiar to us as milky white bags attached to tree limbs. Two straight years of defoliation can permanently damage or kill a tree.

Insecticide treatments will be administered using low-flying aircraft flying just above the treetops, generally during the early-morning hours when temperatures are low, humidity is higher and winds are light. The ODA stressed that the chemical being used here, SPLAT GM-O, will not harm people, pets or plants. The pheromone-based insecticide works by disrupting the gypsy moth’s mating process.

Days before the spraying begins, the ODA will distribute information about the timing of the suppression effort via social media, postcards, news releases and signage in the affected neighborhoods. Also, starting in May, a recorded message with details on the spraying will be available by calling 614-387-0907.

The gypsy moth was accidentally introduced in the U.S. by a French artist, E. Leopold Trouvelot, in the Boston suburbs during the late 1860s. Trouvelot was experimenting with methods of silk production, but after his moths escaped and defoliated the trees in his neighborhood, he moved back to France.

Gypsy moths first appeared in Ohio in 1971, in Ashtabula County, and by the 1990s had spread across most of the state. This spring’s suppression efforts are largely focused on southeast Knox County in the Martinsburg area, eastern Licking County, and then southeast into Noble County.

Residents may publicly comment on the program through Feb. 28 by emailing For more information on gypsy moths and the state’s efforts to eradicate them, visit, or call 614-728-6400.