May 27, 2020
- The target tree (oak) leaf development still has a little bit to go, but we are starting to get very close to the ideal spray window. Factoring in the weather and timing, it looks as though Monday-Wednesday, (June 1-3) may be the ideal spray window. This will be weather dependent.
Gypsy moth is a notorious pest that feeds on the leaves of oaks, aspen and many other species of shade and forest trees.Many Michigan residents have heard of the gypsy moth, though they many not know what the insect looks like. Gypsy moth is a notorious pest that feeds on the leaves of oaks, aspen and many other species of shade and forest trees.
Gypsy Moth Spraying Program Map
Click here for Interactive Map
(Use the Parcel Search option on the right side of the map)
For many years, Cascade Township has participated in a local program to spray for gypsy moths caterpillars, and plans are underway to once again spray for these potentially devastating pests. The 2020 spray program actually began last fall, when the township hired a firm to survey the Township for gypsy moth egg masses. This process allows us to limit the spray areas to those places most likely to see an infestation (see map to view spray area
). This year, the Township will be spraying 736 acres.
In order to treat the gypsy moth, the designated areas will be sprayed with a non-toxic biological agent called Bacillus thuringiensis or “Bt.” Below are some frequently asked questions about gypsy moth caterpillars and the treatment program.
What does a gypsy moth caterpillar look like?
Gypsy moth caterpillars are typically around two inches in length, and can be identified by their distinctive markings. They typically have a yellow head with black markings, followed by prominent blue and red spots along the length of their body. They can be found in over 250 species of trees, though they are especially found where Oak trees are abundant, and they do not spin silk tents, unlike the native and relatively harmless Eastern Tent Caterpillar
How does “Bt” affect the gypsy moth caterpillars?
“Bt” is a naturally occurring bacterium common in soils throughout the world. When a gypsy moth caterpillar eats leaves sprayed with “Bt” the bacterium produces a protein that reacts with the cells of the digestive tract lining of the gypsy moth caterpillar. The “Bt” proteins essentially paralyze the digestive track of the caterpillars, which will then cause them to stop feeding and eventually kill them. The gypsy moth caterpillars will typically die en masse two to three days after spraying occurs.
Is “Bt” dangerous to people, pets, wildlife or other beneficial insects?
The primary benefit to the use of “Bt” in controlling the gypsy moth population is that it is naturally occurring bacterial disease of insects and is non-toxic and safe for people, pets and wildlife, and some formulations can be used on essentially all food crops. Additionally, unlike most insecticides, “Bt” does not have a broad spectrum of activity, so they do not kill beneficial insects including natural enemies of insects (predators and parasites) as well as beneficial pollinators, such as honeybees.
For 2020, it is anticipated that the gypsy moth caterpillar spraying program will take place over the course of a week (or less). We will post the date when it is finalized. The application is done by helicopter, and typically takes one day to complete. Residents who reside within the spray zones will be receiving direct notification of the program through the mail.
Remember, the gypsy moth does its damage during the caterpillar stage, which is during mid-May to mid-June. If your trees are being defoliated later in the summer, it's caused by something other than gypsy moths.
Residents in spray areas need not remain indoors while spraying is underway and can safely go about their regular daily activities. As "B.t." is released into the air, it will descend upon trees and grounds in a light mist which will be barely discernible. Residents can expect to find dead caterpillar larvae in and around their yards upon completion of the insecticide application.
Learn more about the Gypsy Moth