Now is time to look for gypsy moth egg masses
Weekly News Article Published: September 8, 2009 by the Central Office
MADISON – Now is the time to land owners and managers to start looking for gypsy moth egg masses to predict the pest’s population size and potential damage to trees next year. Most egg masses will be found on tree trunks and the undersides of branches, but they can also be found on buildings, firewood, vehicles, and other outdoor objects.
Gypsy moth egg masses
WDNR Photo
State forestry officials say that if there are several egg masses per tree over a large area, such as a neighborhood or woodlot, that area would be best treated from the air next spring. The egg masses are tan-colored, about the size of a nickel or quarter, and feel firm. Older egg masses that are soft and faded are not a concern because the eggs hatched this past spring.
Homeowners with egg masses on individual yard trees can help to reduce the population by removing egg masses within reach and drowning them in soapy water for two days, or by applying horticultural oil available at many garden centers and other retail outlets. Treating egg masses with a horticultural oil spray is one of the best tools available for reducing gypsy moth populations and helping to protect yard trees from defoliation by gypsy moth caterpillars next summer. The best time to oil egg masses is anytime after the first hard frost in fall through the first week in April, on a day with at least 40 degree temperatures.
Property owners should also consider using physical controls, such as sticky barriers and burlap bands, next spring when the caterpillars are present. Insecticide treatments may also be appropriate to control caterpillars if they are very numerous. Visit Wisconsin Gypsy Moth [exit DNR] for advice on gypsy moth management.
The Department of Natural Resources offers an aerial Suppression Spray Program to communities and landowners in the eastern half of Wisconsin that are suffering from outbreak populations of gypsy moth. The program is offered through participating county governments at the request of local municipalities and homeowners. Eligible areas must be 20 acres or more, but this area can cover multiple landowners.
“The purpose of this aerial spray program is to prevent heavy defoliation that may kill the tree,” said Mark Guthmiller, Regional Gypsy Moth Suppression Coordinator with the Department of Natural Resources (DNR).
“County and community participation usually depend on the number of gypsy moth reports they receive from their residents, so call local contacts soon if you are interested in having your property sprayed next spring,” advises Guthmiller.
Homeowners in residential areas should report their gypsy moth problem to the local contact or community government; woodlot owners should contact their township government, the county coordinator or county government directly. Infestations should be reported by the end of September if possible, as counties must apply to the DNR program by early December.
A list of county coordinators and municipal contacts is available online at Wisconsin Gypsy Moth [exit DNR]. Click on the red part of the red and white map and then choose your county on the next page that comes up.
“We are forecasting a lesser gypsy moth problem in 2010, especially in central Wisconsin,” said Bill McNee, another Regional Gypsy Moth Suppression Coordinator with the DNR. “However, there are some regions in the state where populations have remained high or have increased dramatically. These areas include Dane, Sauk, northern Oconto, and central Marinette Counties as well as portions of southeast Wisconsin.
For more information visit Wisconsin Gypsy Moth [exit DNR], e-mail dnrfrgypsymoth@wisconsin.gov, or call 1-800-642-MOTH (6684) for help.
FOR MORE INFORMATION CONTACT: Mark Guthmiller, Regional Gypsy Moth Suppression Coordinator for south central Wisconsin, (608) 275-3223; Andrea Diss-Torrance, Gypsy Moth Suppression Program Coordinator, (608) 264-9247; or Colleen Robinson Klug, (608) 266-2172
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