MADISON - Emerald Ash Borer had been confirmed at Yellowstone Lake State Park, prompting the Department of Agriculture, Trade and Consumer Protection to renew a reminder against transporting firewood between counties.
Lafayette County was quarantined last summer, along with Green and surrounding counties, prohibiting ash wood products and hardwood firewood from being moved to areas not quarantined.
EAB was confirmed in the town of Decatur in Green County in April.
DATCP strongly recommends against moving firewood even within quarantined areas in order to slow the spread of the tree-killing beetle.
"The vast majority of EAB infestations have resulted from the movement of firewood, as evidenced by the number of times our first find in a given county has been in campgrounds. Most of the quarantined counties are not generally infested, so moving firewood within them could bring the pest to new areas in the county that would otherwise remain uninfested for several years," Brian Kuhn, DATCP's Bureau of Plant Industry, said in a statement the department released Friday.
Other forest pests and diseases also move easily and invisibly from one location to another under the bark of firewood, Kuhn said.
Four adult beetles were found Monday in traps set at the park as part of routine monitoring. DATCP send samples to the U.S. Department of Agriculture for official confirmation, which was received Wednesday.
Quarantines are used against the spread of EAB because it is not susceptible to aerial spraying used to control the gypsy moth, DATCP spokesperson Donna Gilson said.
"The gypsy moth works differently than the EAB. Their caterpillars make good targets for aerial spraying but the EAB lives under the bark and it would take a tree-by-tree approach it get them," Gilson said.
Adult EAB also disperse quickly after hatching and do not live in close proximity like the gypsy moth, she said.
Property owners living within 15 miles of a reported EAB infestation can treat their ash trees to prevent them from succumbing to the bugs. A concentrated liquid, available at home improvement stores, can be diluted and poured on the ground around the tree's base so the roots can take it in and send it to the tree's protective inner bark layer, Gilson said.
Injecting trees with an insecticide is another preventative measure but is best left to certified arborists, she said.
Once infested, it can be too late to save an ash from the EAB, but Gilson said a certified arborist can give an opinion on a particular tree's survival chances.
The state has an estimated 834 million ash trees and the four types of ash trees make up about 7 percent of the trees with a diameter of 1 inch or more, according the Department of Natural Resources.
All types of ash trees, white, green, black and blue, are susceptible to EAB. All four also have similar characteristics that distinguish them from maple, oak, or elm trees including:
n opposite branching, twigs and leaves attach directly opposite each other, occurs in few tree species;
n compound leaves, separate leaflets on each leaf stem;
n five to 11 leaflets per leaf stem depending on the variety.
Box elder trees can be confused with ash trees. DNR experts can identify ash trees if sent close-up photos of the leaves and branches to: www.emeraldashborer.wi.gov or call, 1-800-462-2803
The adult EAB is found from May to August on and around ash trees. It has bright metallic green body which is bullet shaped and measures about one-half inch long and one-eighth inch wide. Unlike the tiger or Japanese beetle, the EAB has no stripes or other markings on its body.