Frequently Asked Questions
In an effort to supply the answers to your questions quickly, The Clare County Gypsy Moth Suppression Program maintains this list of the most frequently asked questions.
Why does Clare County spray for gypsy moths?
Gypsy Moth caterpillars feed on the leaves of many trees, especially oaks, and their populations can grow so quickly that they can strip all the leaves off of entire stands of trees, damaging them severely. When surveys indicate that the population of the pest in an area is large enough to cause defoliation of trees in June, reduction action is taken. Spray treatments reduce such outbreak populations below the level at which they can cause heavy defoliation.
What insecticide is used?
Sites will receive a single aerial application of the microbial insecticide Foray 48B, a brand name for Bacillus thuringiensis var. kurstaki (commonly called Btk). The active ingredient is a naturally occurring soil bacterium that kills Gypsy Moth caterpillars when they eat it. Btk is specific to Lepidoptera species of caterpillars that ingest it and will not harm humans, bees, birds, fish, pets, and other wildlife. Btk is highly unlikely to cause any adverse health reactions. It is possible, but very unlikely, that people with severe food allergies or asthma may react to the spray. If you suffer from such conditions, the Clare County program suggests that you leave the area to minimize your risk of reactions. It is also advised that everyone in a spray area should take the simple precaution of staying indoors with the windows closed while the planes are spraying to avoid direct exposure. The District also recommends keeping pets indoors due to the loud noise of the spraying that may spook them.
Was my property chosen for spraying this year?
The Clare County gypsy moth program makes spray block maps available on their website as soon as treatment areas are finalized. To find out if your property is in a spray block, look at the current spray maps. Each year in March or early April the parcels chosen for spraying are mailed a spray notice. Also, a notice of spraying also appears in the local newspapers, our website and social media.
Why wasn't my property chosen for spraying this year?
The gypsy moth program has been sustained by a millage that was collected from 2000-2005. Unfortunately, the funding is limited. We sprayed the heaviest populations based on the fall counts that we had funding for that would have the most impact ie; areas of highly populated residents, public parks, and tourism areas.
When are spray blocks treated?
Spray projects are timed for when the caterpillars are in the first 3-4 weeks of development and leaves are expanded enough to intercept the spray. The timing is based on actual observations of caterpillars and leaf development. Spraying typically begins in mid-May or as late as early June. Weather permitting, spraying may begin as early as 6:00 am and continue as long as weather conditions remain favorable. Please check with the Gypsy Moth web site or office line at (989) 539-6401 by mid-May for updates. In previous years, spraying has taken place near Memorial Day.
What if I object to the spraying of my property?
Because Clare Counties Gypsy Moth Suppression Program is funded by a county-wide millage, anyone residing in a proposed spray block will be sprayed. Those who do not want his or her property sprayed can opt out.
Why was I not sprayed? I received a letter in the mail.
It is a requirement that the all opted-out properties receive a 600 foot buffer unless that it is noted that the landowner waived the buffer. This is ensures that the opted-out property does not receive any drifting spray. If the remaining spray block is or a potential spray area is less than 25 acres it is eliminated because the aerial applicator cannot treat it.
Why is there a Suppression Spray Program?
- Numbers of Gypsy Moths often go through a cycle of increased numbers every 5 to 10 years.
- The goal of the Suppression Program is to protect valuable trees from mortality by controlling gypsy moth population outbreaks in areas where the gypsy moth is established.
- The Suppression Program assists communities and landowners in the management of gypsy moth by providing the expertise and equipment for aerial sprays and applying to the Federal government for potential cost sharing. Treatments under this program are paid for by the Clare County millage. If federal cost sharing is available, the state will use less money from the millage fund.
- The program uses naturally occurring soil bacteria, Bacillus thruingiensis var. kurstaki or B.t.k., applied by aerial spray.
- On sites with endangered species that would be affected by B.t.k., other gypsy moth specific treatments are used.