You are here: NRS Home  / Research Programs / Forest Disturbance Processes / Invasive Species / Gypsy Moth / Control and Management

Gypsy Moth

Control and Management

Since early in the 19th century, ground and aerial applications of chemical pesticides, including DDT and other agents have been used for population control of gypsy moth (GM). Use of these products eventually declined because of their negative impacts on the environment and on human health and the resulting outcry by residents of infested areas. Beginning in the 1970s, Forest Service research efforts focused on developing and improving safe and environmentally friendly microbial pesticides, resulting in dramatic improvement and increased use of Bacillus thuringiensis k (Btk) formulations and a naturally occurring and host-specific nucleopolyhedrosis virus (LdNPA) for GM control efforts. In addition, mating disruption by application of GM pheromones has also been developed and is used extensively in the Slow the Spread program.

Gypsy moth’s long establishment history in North America has led to the development of three types of management, depending upon where gypsy moth populations are located relative to their current range, which continues to expand. For areas in the generally infested area behind the invasion front, the first management type is suppression of gypsy moth outbreaks to reduce effects on people and the environment are conducted, primarily via aerial application of microbial pesticides and insect growth regulators. 

As of 2013, the invasion front reached from North Carolina up to Minnesota and there were more than 56 million acres of highly susceptible forests not infested in a total of 19 states. Economic analyses indicated that the second type of management, slowing the spread of GM, is a more realistic and attainable goal than is eradication. In 1999, the national “Slow the Spread” (STS) program, a cooperative federal--state program, was put into action along the expanding population front. This program, by slowing the spread of GM, delays the ecological effects and reduces the costs of classical management program and allows biological controls now present in the populations behind the front to catch up and become active. Consequently, the states have embraced STS and results to date suggest that under STS, the rate of gypsy moth spread has been reduced from historical levels of 20 km/yr to just 5 km/yr.

The third type of management, eradication, is used for outbreaks far outside of the STS zone. In this area, small isolated populations of GM are eradicated using mass trapping and mating disruption, with occasional applications of microbial pesticides.  These small, isolated populations are created when people accidentally move GM with household goods, firewood, or commercial products.  In addition to these three types of direct control management actions, other management actions are used to reduce spread via quarantines and inspections or to reduce susceptibility and vulnerability such as replacing susceptible urban trees with more resistant species or doing silvicultural management to reduce effects in forested areas.

Our Research

Last Modified: August 17, 2015