Local Department of Natural Resource officials report finding numerous gypsy moth egg cases in Portage County for the first time.
"Usually where you find some, you find quite a few," said Paul Lochner, DNR forester at the Whiting Ranger Station.
Most of the egg cases have shown up on the Arnott moraine east of the Stevens Point/Plover area, stretching from Highway 10 to Bancroft, Lochner said. Some have also been found along Sixth Avenue in the town of Almond.
The teardrop-shaped egg masses are about one-and-a-half inches long and look they are made of buff-tan felt. They're usually laid in protected areas, like rough tree bark, wood piles, under the eaves of homes and the undersides of vehicles.
Lochner recommends persons finding egg masses scrape them off into a coffee can filled with oil or put them in the garbage or burn pile.
"It's a not a foolproof way of cutting your population down to zero, but it's something people can do," Lochner said.
He recommends against spraying pesticides, because that could kill some of the few natural enemies gypsy moths have.
Survey crews working for the Department of Agriculture, Trade and Consumer Protection found no sign of a gypsy moth population explosion here in 2000, though 2,457 males were trapped in the county in 1999.
"The male trap catch for Portage County is down from last year, which reflects a reduction in the population of the pest," said Andrea Diss, gypsy moth program coordinator for the DNR. "As far as I am aware, gypsy moth is still a fairly rare insect in your county. The distribution maps for trap catch will be available in November, but given past results, I expect that gypsy moth catches are concentrated in the eastern part of Portage County. This area is dominated by pin oak and dry, sandy soils, conditions favorable for gypsy moth.
"Gypsy moth eggs can be killed by overheating on sunny fall days and by freeze-drying when temperatures drop below -20 for several days during winter. A hard winter would be helpful in reducing the numbers of this pest. ...
"Since the gypsy moth is still fairly rare in Portage County, especially on the west side of the county, it is important to prevent accidental introductions. If you bring items from gypsy moth infested areas that have been outdoors during July and August, check them for egg masses."
Outdoor items that can harbor egg masses include nursery trees, particularly evergreens, trailers, camping vehicles and firewood. Areas of North America where gypsy moth are common include all states in the northeast and down the Atlantic coast to the North Carolina border. Also, Ohio, Michigan, Ontario, Quebec and, increasingly, counties in Wisconsin bordering Lake Michigan and Green Bay west to Winnebago County.
Areas which have many gypsy moths are in a quarantine zone, and restrictions are placed on transporting things that might harbor egg masses, such as nursery stock, Christmas trees and logs. But, said Diss, "I do not expect Portage County to be placed under quarantine this spring."
The gypsy moth is an Old World native that was brought to the United States in 1869 with the intent of crossing it with silkworms and creating a hardier species. Instead it became a nuisance, defoliating trees, especially oaks but also other species.
In its caterpillar stage, gypsy moths eat leaves. During years with population explosions, they can defoliate trees, usually in late June to early July.
Healthy trees are able to grow a second set of leaves, which will provide enough energy for the trees to survive, Lochner said.
"The ones that aren't doing really good, because of other conditions (like being old, decrepit or crowded), those are the ones most likely to die," Lochner said.
Through active forest management practices, landowners can improve the vigor of their woodlands so their timber stands can better withstand gypsy moth defoliation.
In Wisconsin, bacterial pesticides have been used against the moths. In the 1950s Long Island was drenched with DDT to kill the insect but that didn't stop it. It did, however, inspire a chapter in Rachel Carson's book, "Silent Spring."
"Decisions on where to conduct treatments next spring," said Diss, "will be made in November once the trapping data is processed and the egg mass survey is complete."