Gypsy moths
Gypsy moth is a non-native insect that has been destroying and threatening woodlands in the United States for over a century. The gypsy moth caterpillar does the damage by feeding on the leaves of over 300 species of trees and shrubs. Their feeding takes place from early spring until July and can stress, defoliate and kill trees. Very few natural enemies and a seemingly endless array of hosts make the gypsy moth one of the most dangerous pests in the country.
While gypsy moth is not yet an established pest in Minnesota, it has been found here. State officials monitor the gypsy moth population and take actions to eradicate it when moths are detected. Treatments that target the gypsy moth in its caterpillar stage have been effective in suppressing its further spread and establishment.
Gypsy moths do spread naturally on their own but can also spread much quicker if they “hitchhike.” Transport of egg masses on firewood, camping equipment, and automobiles is common. Individual egg masses can contain between 500 and 1,000 moth eggs. These eggs hatch into caterpillars in the spring, and each caterpillar can eat up to 11 square feet of foliage in its lifetime. It’s important to check your vehicle and equipment before leaving a gypsy moth infested area, or you might bring them home with you.
Has gypsy moth been found in Minnetonka this year?
A 2010 survey by the MN Department of Agriculture found that an isolated population of gypsy moths has become established in the OPUS area of Minnetonka. Ranked as one of America’s single most destructive pests of trees and shrubs, this infestation is a threat to trees on both private and public land in Minnetonka. The MDA will be working closely with residents as well as city and federal cooperators in the spring of 2011 on management efforts to eradicate this population of gypsy moths before it can spread.
For details on control treatments, visit:
Who is in charge of finding gypsy moths in Minnetonka?
At this time, the Minnesota Department of Agriculture (MDA) is the lead agency for the control of gypsy moth, with support and cooperation also coming from the US Department of Agriculture (USDA) Forest Service and the USDA—Animal and Plant Health Inspection Service (APHIS).
Each summer, the MDA completes a trapping program that targets male gypsy moths. The traps are baited with a pheromone that mimics female gypsy moths, which cannot fly. When higher numbers of the males are found, a survey is conducted the following winter to search for egg masses, which would indicate a reproducing population of gypsy moths. If egg masses are confirmed in the survey, the MDA plans a control treatment in the spring to eradicate the gypsy moth in its caterpillar stage.
What is the history and background of gypsy moth?
Gypsy moths were introduced to America from Europe in the 1869 in an attempt to breed a hardier silk worm. Instead, the caterpillars escaped and headed for the trees with disastrous effects. Their ability to feed and survive on more than 300 trees and woody plant species makes the moths at home in North America and they have slowly spread westward in recent decades. Gypsy moth populations are currently established from Wisconsin to the east coast of the United States.
In 1912, the USDA declared gypsy moths a federally regulated pest and has since quarantined all or parts of 19 states. The MN Department of Agriculture has had a gypsy moth monitoring program since 1973, with traps set to detect the insect throughout the state.
Minnetonka was treated for gypsy moths in 1990, which eradicated the population. Neighboring communities have found higher numbers of gypsy moth in the last ten years. Golden Valley and Minneapolis were treated in 2002, Edina in 2004 and Brooklyn Park in 2006. Portions of Minnetonka were spray-treated in 2007 and in 2009.
Who should I call if I have questions about or think I have seen a gypsy moth?
The Minnesota Department of Agriculture (MDA) is the lead agency in the fight against gypsy moths in Minnesota. If you think you have seen a gypsy moth, call the MDA’s Arrest the Pest hotline: 651.201.MOTH (6684). To learn more about gypsy moth, visit their website at www.mda.state.mn.us/gypsymoth
How can I help?
Don’t move firewood.
Residents should be on the lookout for buff-colored fuzzy egg masses, which are about the size of a quarter. Inspect your vehicle and camping gear for egg masses before coming back to Minnesota after spending time in a quarantined area, or an area where gypsy moth is established as a “permanent” resident, such as eastern Wisconsin. See the MDA’s map to learn more.
At home, look for egg masses under eaves and decks, in fences, on tree trunks and under firewood piles. If you find an egg mass, call the MN Department of Agriculture’s Arrest the Pest hotline at 651.201.MOTH (6684).
Will I be penalized if a gypsy moth or egg mass is found on my property?
There are no penalties if the moth is found in a resident’s yard. The MN Department of Agriculture will handle any treatments and if it is found on a tree, it need not be cut down.
Is there a cost to me if gypsy moth is found in my neighborhood?
At this time, state and federal funds exist to control this pest at no additional cost to residents.
How can I find out more about the gypsy moth treatments?
There are several of management practices used to control gypsy moth. To learn more, go to www.mda.state.mn.us/gypsymoth.
Like a butterfly, the gypsy moth has four life stages:
- Egg mass
- larvae (the caterpillar)
- pupa (the cocoon)
- flying moth
