Norfolk County will be conducting an aerial spray of pesticide on select Norfolk County-owned woodlots for the purpose of controlling a gypsy moth outbreak.

The County will be using the biological insecticide Foray® 48B (Pest Control Products Act #24977) in an effort to reduce the impacts of gypsy moth defoliation on specific County-owned properties. The active ingredient is a soil-borne bacteria (Bacillus thuringiensis v.kurstaki (Btk)) that is applied to the leaves of trees while caterpillars are feeding in their early instar stage. Btk specifically targets Lepidoptera feeding in the upper canopy and is non-toxic to birds, animals, humans, fish, and most other insects including bees.

The spray will take place anytime between mid-May and early June.  Application will be undertaken in low wind and high humidity conditions, typically in the early morning or mid-evening. There will be two applications approximately 1 week apart. A public notice sign will be posted at the entrance to each property in advance of treatment.

Gypsy moth is an invasive insect native to Europe that feeds on a wide variety of trees, but has a strong preference for oak species. Since approximately 2017, Norfolk County has been experiencing a building gypsy moth population. Significant gypsy moth defoliation has been observed throughout Norfolk County since 2018.

The application of the pesticide will be completed by Zimmer Air Services Inc.

To see which County Woodlots will be sprayed, or for more information, please visit Norfolk County’s Forestry Management page or contact Adam Biddle, Supervisor of Forestry, by phone (519) 426-5870 ext. 2224 or by email