Gypsy Moth Treatments: Mating Disruptors

​​​​​Mating disruptors are pheromone-based products. The pheromone is the scent of the female moth that attracts male moths. When we spread the pheromone in an area, it confuses the males so they cannot find females. We apply mating disruptors in June and July, just before adult moths normally mate.

The pheromone is specific to gypsy moths and has no effect on any other species of insect, or on humans or animals. ​Mating disruption treatments are effective only when gypsy moth populations are low. When the populations are higher, male moths will find females by chance even if they cannot follow a pheromone scent trail. 

There are three mating disruption products available, all applied aerially:

  • Disrupt® II pheromone flakes are tiny pieces of plastic  treated with pheromone and applied at variable rates, with the low rate of one or two flakes per square foot of tree canopy.
  • SPLAT® GM is delivered in small, waxy droplets sprayed onto the tree canopy at the rate of about two ounces per acre.
  • SPLAT-GMO® is an organic-approved version of SPLAT-GM®. 

​When do you spray mating disruptors?

​We usually begin spraying mating disruptors in southern Wisconsin in June or early July and move northward, finishing in late July. Planes may start spraying as early as 6 a.m., weather permitting, and may continue into the evening.

Are the pheromone-based products harmful to humans or animals?

None of the products are harmful to humans or animals. They simply carry and release the pheromone of the female gypsy moth that is detectable only by male gypsy moths.

The low-flying planes may frighten pets or livestock and we recommend keeping them inside if possible.

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