Wisconsin Department of Agriculture, Trade and Consumer Protection taking comments on use of Mustang® Maxx on cherries

Wisconsin State Farmer
Special registration of Mustang® Maxx on cherries will allow growers to use the product up to three days before harvest due to the increasing susceptibility to spotted wing drosophila as cherries ripen.

MADISON – Public comments will be accepted through June 15 on a proposed special pesticide registration of the insecticide Mustang® Maxx for use on tart cherries.

The special registration by the Wisconsin Department of Agriculture, Trade and Consumer Protection will allow growers to use the product on tart cherries up to three days before harvest. The product is already registered for use in Wisconsin on stone fruits including tart cherries. However, the pre-harvest interval is 14 days, meaning it cannot be used in the last two weeks before harvest.

Mustang® Maxx contains the active ingredient zeta-cypermethrin and is registered by FMC Corporation. It is used on a wide variety of fruit, vegetable and forage crops as well as corn and soybeans. The pre-harvest interval will remain at 14 days for all crops except tart cherries.

The special need for the cherry crop arises from their increasing susceptibility to spotted wing drosophila as they ripen. Spotted wing drosophila is a non-native fly that has appeared in Wisconsin in the past 10 years. The flies cut slits in the skin of the fruit and lay their eggs. The larvae, or immature flies, then feed on the flesh of the fruit, causing soft spots and brown sunken areas.

Although the flies target many species of fruit, cherries are particularly susceptible, because the insects’ population buildup coincides with the ripening tart cherry crop. By law, there is zero tolerance for larvae in harvested cherries. Other insecticides are available, but less effective or have longer pre-harvest intervals.

The preliminary environmental assessment indicates that the proposed registration will not require a full environmental assessment. This special registration will expire Dec. 31, 2020. 

For a copy of the assessment, contact Alyssa Foss, DATCP, P.O. Box 8911, Madison, WI, 53708-8911, 608-224-4547. It is available for review at the department Monday-Friday, 7:45 a.m.-4:30 p.m., 2811 Agriculture Dr., Madison, second floor.

Comments received on or before 4:30 p.m., June 15, will become part of the preliminary environmental assessment record. Send comments to Alyssa Foss by mail at the above address or by email at

The special registration process allows states to register additional uses of pesticide products without prior federal approval. It helps growers address local pest problems that cannot be adequately controlled by any available federally registered product.

These problems include insect outbreaks, fungal diseases, and grasses and weeds that outcompete crops. Details about the special registration process are available at