Spongy Moth Management

The MDA uses Bacillus thuringiensis kurstaki (Btk) formulated in the product Foray or the mating disruption product SPLAT GM-O. Btk is used in areas that have many male moths captured and where egg masses are found. SPLAT GM-O is used in area where low populations of spongy moth were detected. 

Btk is a naturally, occurring bacterium that is found in the soil. The product is applied to the treetops where spongy moth caterpillars are feeding. When ingested, the bacterium is toxic to certain susceptible caterpillars like the spongy moth. Caterpillars stop feeding and die within a couple days.

Foray is the commercial product containing Btk. The inactive ingredients used in Foray are certified organic food-grade ingredients and contain no petroleum solvents. The Foray Btk is not genetically engineered and the product is gluten free.

Applications occur twice, about a week apart. Application normally takes place early in the day when low winds and high humidity allow the product droplets to land on tree tops where they will be the most effective. A management site will typically be finished before children are walking to school or people are heading to work.

The product is applied to the treetops by low flying aircrafts where spongy moth caterpillars are feeding, often this occurs in May and June. 

When the caterpillars feed on the leaves, they ingest the products. The bacterium in Foray is toxic to the caterpillars, they stop feeding, and die within a couple days.

Mating disruption uses pheromone-based products to confuse adult moths and prevent them from reproducing. Mating disruption floods the area with the scent of the female moth and confuses male spongy moths so they cannot find females. They die without reproducing. The product does not actually kill moths.

Pheromones are non-toxic compounds that insects use to communicate. The female spongy moth does not fly and must attract the male moths with pheromones.

SPLAT GM-O is an certified organic, non-toxic, biodegradable product for the control of spongy moth. It is made of food grade materials and has the consistency of hand cream. SPLAT GM-O uses pheromone to disrupt spongy moth mating habits without impacting other insects, mammals, or the surrounding environment.

Btk has a proven safety record with people, pets, birds, fish, livestock, and other insects such as bees; and has been registered and re-registered many times by the Environmental Protection Agency (EPA) for use in the U.S., to use on more than 200 food and fiber crops.

People are exposed to Btk through contact with soil in the natural environment or through their diet, at very low levels. If you eat fresh fruits or vegetables, you probably have already ingested this bacterium. It is commonly used on commercial and organic food crops.

Some people have reported mild skin reactions or mild eye, ear, and nose irritations after Btk treatments. Others have reported mild hay fever reactions. Health officials have studied these reports extensively and have not been able to determine if the reactions were caused by Btk or by pollens, molds, or dust generated during the treatments, or were unrelated to Btk treatments.

Public health officials state Btk is not a public health risk.

Although we don't have evidence that Btk will affect any given group of people, individuals with a weakened immune systems or serious food allergies may choose to avoid any potential exposure by staying indoors during and at least 30 minutes after the treatment, or leaving the area during the application. 

Given the long history of use and the knowledge that regulatory and public health officials have about Btk and Foray, there is no reason to suspect that either Foray or Btk is carcinogenic.

You can read more about Bt and human health from the National Pesticide Information Center.

SPLAT GM-O is completely non-toxic and harmless to humans and animals. All the ingredients in SPLAT GM-O are listed by the EPA as safe and have been approved for food use. 

Scientific research shows that SPLAT GM-O is not harmful to humans. Individuals with a weakened immune systems or serious food allergies may choose to avoid any potential for exposure by staying indoors during and at least 30 minutes after the treatment, or leaving the area during the application.

Neither SPLAT GM-O or Btk are toxic to humans, other mammals, fish, birds, or honeybees. SPLAT GM-O is biodegradable and uses pheromones to disrupt the mating activities of the spongy moth. It is a non-lethal means of control. Btk only works under the conditions present in the stomach of insects in the caterpillar stage of development. This condition is not present in the stomachs of humans, mammals, fish, birds, or honeybees.

SPLAT GM-O is formulated to specifically target the spongy moth. It will not impact the mating activities of other insects. For Btk have any effects, caterpillars must be actively feeding within approximately two weeks after treatment, they must eat the Foray, and they must be susceptible to the bacteria. The MDA works with the Minnesota Department of Natural Resources and the U.S. Fish and Wildlife Service to identify and evaluate impacts to any threatened or endangered species, and ensure that no sites of sensitive, threatened, or endangered species of moths and butterflies overlap with Foray treatments.

Neither SPLAT GM-O nor Btk/Foray will harm the paint on your vehicle or outdoor structures. Both can be easily washed off. For SPLAT GM-O, use a mild detergent and water to wash the product off as you would road grime. Clothing can be cleaned with hot water and laundry detergent. Btk/Foray will show more readily on dark colored vehicles. If left in the sun for a few days without washing, the spray deposits on vehicles may have to be rehydrated in order to remove it. Take an old bath towel and soak it in sudsy water and drape it over the vehicle for a few minutes. More ‘elbow grease’ may be required if the spray deposit is left on the vehicle for several days.