The gypsy moth is one of America’s most destructive forests pests. The pests eat the leaves of many trees and shrubs, favoring oak, poplar, birch and willow. The caterpillars can defoliate large sections of trees, causing ecological harm to the landscape, economic harm to forest resource industries, and a nuisance for people. Severe, repeated infestations can kill trees, especially when the trees are already stressed by drought or other factors.
Learn more about the gypsy moth.
These hungry pests are found throughout Wisconsin and are now establishing populations in eastern Minnesota. Nationwide, a system of trapping, treatments, and regulations has kept Minnesota gypsy moth-free for decades, but in recent years moths have been trapped in increasing numbers along the North Shore. Therefore, the Minnesota Department of Agriculture (MDA) enacted a quarantine of Lake and Cook counties on July 1, 2014, to restrict movement of potentially infested items and thereby contain the infestation.
A quarantine is a set of rules intended to prevent the artificial spread of organisms from infested areas to uninfested areas. Quarantines have been established by the states and federal governments to contain known populations of gypsy moths. The quarantines are generally along county lines and are established only after several criteria are met. The Commissioner of Agriculture has statutory authority to issue a quarantine to limit the spread of plant pests like the gypsy moth.
A 45-day comment period on the proposed quarantine of Lake and Cook counties closed on March 12, 2014. The proposal was amended to account for comments received during the comment period. The Commissioner of Agriculture signed and formalized the quarantine, with implementation on July 1, 2014.
Gypsy moths are expert "hitchhikers" and are most commonly transported as egg masses. The female will lay her eggs on any solid surface. Quarantine violations occur when companies or individuals knowingly transport any life stage of gypsy moth (egg, caterpillar, pupa, or adult) out of the quarantined area with an inspection or a compliance agreement from a state or federal agency. Knowingly transporting uninspected or untreated materials out of quarantined areas can lead to civil or criminal penalties.
Nursery stock shipped out of a quarantine by a nursery or dealer must be treated or visually inspected and certified pest-free. Shippers must be operating under a compliance agreement with state or federal agriculture agencies prior to moving stock.
Trees cut in a gypsy moth quarantined area must be treated during the growing season prior to shipping. Growers operating under a compliance agreement are eligible to certify, document, and ship loads.
Shippers operating under a compliance agreement must document all loads leaving the quarantine and specify the destination. Treat or remove any life stages found upon inspection. Receivers of quarantined products must operate under a compliance agreement and follow the guidelines set within for processing procedures.
Self-inspection using the checklist (PDF) is allowable while homeowners are packing up household goods to move. Treat or remove any life stages found upon inspection. Those using a moving company or portable storage must include the completed checklist with the shipment. Qualified Certified Applicators or state/federal agriculture agencies may provide inspection assistance.
Inspection and documentation are required prior to moving outside of the quarantine. Qualified Certified Applicators or state/federal agriculture agencies may provide inspection assistance.
The MDA, in partnership with federal, state, tribal, and local officials, has been trapping gypsy moth since 1973 and treating since 1980. Since the first northern Minnesota treatments around Schroeder in 2006, the MDA has taken action to prevent and stifle the growth of gypsy moth populations in Lake and Cook Counties. Populations have now grown to a point where treatments are ineffective and the MDA has to turn to other management strategies to contain the infestation.
The first gypsy moth quarantines were enacted in 1912 in New England. Minnesota will be the 21st state to be completely or partially quarantined for this invasive species. Quarantines in other states have benefitted Minnesota’s forest resources by keeping them gypsy-moth free until now. The proposed quarantine can protect uninfested forests to the west and south.
For questions on gypsy moth or the proposed quarantine, call MDA’s Arrest the Pest Hotline at 888-545-6684 or email firstname.lastname@example.org.
Minnesota Department of Agriculture (MDA), 625 Robert Street N, St. Paul, MN 55155-2538, email@example.com