Spongy (Gypsy) Moth

Notice of Aerial Spraying for the Suppression of *Spongy (Gypsy) Moth Larvae in Selected Areas of the City of Walker

Certain areas in the City of Walker are scheduled to receive aerial application of the bacterial agent Bacillus thuringiensis (B.t.) for the suppression of Spongy Moth larvae. Maps of these areas are available for viewing at Walker City Hall and online here. The applicator for the program is Hamilton Helicopters, Inc., P.O. Box 264, Hamilton, MI 49419, 616-291-5808. The B.t. brand will be Foray, supplied by Valent Biosciences Corporation. The spraying will be done by aircraft when the weather conditions are suitable. There is no cost to be included in the spray program. At this time, spraying is tentatively scheduled for mid-May and early June. The exact date and time of spraying depend on weather conditions, the insect stage, and leaf development.

The insecticide B.t. is derived from a naturally occurring bacteria and is known only to affect caterpillars by destroying their stomachs after they eat the material. It does not affect honeybees or other non-leaf-eating insects, birds, fish or mammals. The B.t. is applied in a very fine mist that targets the trees. The carrier liquid is water and drying usually takes place within a few minutes. Additional information regarding Foray and Spongy (Gypsy) Moths in general:

Spraying in the West Michigan area will begin Monday, May 23, 2022, weather permitting. There will be two to three helicopters spraying various areas in West Michigan during that time, so it will be difficult to say exactly which blocks will be sprayed at a given time. The applicators usually begin around 7 am and will stop for the day when/if the weather conditions become unsatisfactory (high wind, possible rain, low humidity). 

Neal Swanson, Project Manager

*Please note, the Entomological Society of America has recently changed the official common name of Lymantria dispar from "gypsy moth" to "spongy moth." Thank you for your patience while we transition through this name change process."