Forestry officials in British Columbia are planning an aerial attack after having found the highest amount of gypsy moth egg masses ever seen in any specific area of the province.
The province’s ministry of forests and range said Wednesday it now has a pesticide use permit to spray 813 acres of mainly agricultural land on the road to Harrison Lake.
The province said it aims to “minimize the risk (gypsy moths) pose to the region’s forests, farms and orchards.”
The gypsy moth is an introduced pest species, with caterpillars that feed on tree leaves. Large gypsy moth populations defoliated sections of forests and residential areas in Ontario and the eastern U.S. in recent years, the province said.
The moths generally hitch rides into B.C. with unwitting escorts, attached to vehicles, recreational equipment and outdoor household articles such as lawn furniture, coming from affected areas in eastern North America.
In this case, the province said Wednesday, trapping and monitoring point to a growing gypsy moth population south of Harrison Hot Springs, about 30 km northeast of Chilliwack. One hundred egg masses were found in the area, which officials said is “the highest amount ever found in one area in the province.”
The province said it plans to have up to four aerial applications of Foray 48B between April 25 and June 30 to control the moths. The exact application dates will depend on suitable weather.
Foray 48B is approved for use on organic farms and includes the naturally-occurring Bacillus thuringiensis var kurstaki (Btk) as its active ingredient.
Btk, the province said, does not harm humans, other mammals, birds, fish, plants, reptiles, amphibians, bees or other insects and only affects caterpillars after they have ingested it. It’s been approved for control of gypsy moth larvae in Canada since 1961.
The province noted that it treated areas on Saltspring Island and at Saltair on Vancouver Island with ground applications of Foray 48B in spring last year. Neither of those locations require treatment in 2009, the ministry said Wednesday.