The Macomb County Gypsy Moth Suppression Program is a voluntary program available to eligible residential, recreational, and special use property owners. The program is a cooperative effort between the USDA-Forest Service, Michigan Department of Agriculture (MDA), Macomb County and local municipalities. Macomb County Michigan State University (MSU) Extension administers the program.
Why a Gypsy Moth Suppression Program?
The Gypsy Moth is a foreign pest with few native predators to keep populations in check. Caterpillars feed on tree leaves, preferring those of oak, maple, cherry, spruce, poplar, and birch. When those are not available, other tree species and evergreens are also at risk. Large populations can defoliate entire wooded areas. Caterpillars in large numbers and their waste (frass) are a nuisance on residential property. Gypsy Moths can not be eradicated, but they can be suppressed to tolerable levels.
What are the goals of this program?
How are Gypsy Moth Populations Suppressed?
The aerial application of Btk (Bacillus thuringiensis variety kurstaki) is used to reduce high populations of gypsy moth caterpillars at sites that meet MDA requirements for spraying. Bt is a naturally occurring bacterium found in the soil and is not harmful to pets, birds, fish, wildlife, plants, beneficial insects, and humans. Bt is applied when the caterpillars are young (usually in May) to insure the greatest impact in reducing numbers. Alternative mechanical techniques, such as tree banding and egg mass scraping, also reduce caterpillar numbers. The Suppression Program recommends the use of a combination of methods.
How do Gypsy Moths travel?
Caterpillars hang in trees on a silk strand and can be carried a great distance by the wind. Humans also move egg masses or pupal cases on travel trailers, firewood, cars, etc. Vehicular travel is how they came to Macomb County! Make sure you do not give the Gypsy Moth a ride!
How do I know if I have the Gypsy Moth?
A number of MSU Extension bulletins can help you identify the Gypsy Moth and caterpillar. You can also use the Macomb County MSU Extension diagnostic facility. There is a small fee for some services.
For insect identification:
Call Macomb MSU Extension Gardening Hotline:(586) 469-5063, Monday, Wednesday, Friday, from 9 a.m. to 4 p.m.
What does gypsy moth damage look like?
Gypsy moth caterpillars feed on tree leaves creating “Swiss Cheese” type holes. They do not cause pre-mature leaf drop, browning, or curling of leaves. They do not make a web or tent in trees.
What happens when trees are defoliated?
Trees defoliated more than 40% become stressed by using next year’s energy reserves to grow new leaves during the same season. Healthy trees may withstand several years of defoliation. Trees with other stress factors such as drought, could die sooner. Evergreens are unable to replace their needles and may die when defoliated. Keep trees watered and fertilized to lessen any damage.
Should I report a Gypsy Moth Infestation?
YES. To determine if your property is eligible for the Gypsy Moth Suppression Program, report all infestations to the program educator at the Macomb County MSU Extension office. An egg mass survey can be done to assess the level of infestation and determine if an area qualifies for the program. For more information, please call: Macomb MSU Extension Gypsy Moth Suppression Program (586) 469-6264.
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