The discovery of a major infestation of European gypsy moths in Surrey is expected to result in aerial spraying to control the destructive insect for the first time in four years.
The fuzzy leaf-munching caterpillars devour hundreds of types of shrubs and trees, threatening fruit and tree orchards, blueberry farms and Garry oak stands on Vancouver Island.
Nearly 200 male European gypsy moths were caught in pheromone traps over the summer in Cloverdale on trees along 64 Avenue, between 168 and 176 Streets, by the Canadian Food Inspection Agency.
“We think this is the epicentre of this particular infestation,” said Tim Ebata, a forest health officer with B.C.’s Ministry of Forests.
He said the infestation is worse than one in Richmond in 2010 that resulted in more than 700 hectares being sprayed, as well as an earlier attack on a hazelnut orchard near Harrison Hot Springs in 2009.
“Looking closely on the ground they found many egg masses,” Ebata said. “Which is quite surprising. We didn’t expect such a large infestation.”
Adult female European gypsy moth next to a freshly laid eggs. Province of Ontario photo.
The province has not yet formally applied for a pesticide application permit to spray Btk, a bacteria that acts as a biological pesticide against moths and butterflies, but one is expected in the coming weeks.
Ground spraying can be an option and has not yet been ruled out, Ebata said, but added it is unlikely to be as suitable as aerial spraying in this case, which is estimated to cost $1 million.
Gypsy moth egg masses often ride along with vehicles and are attached to things like canoes, lawn furnitures and barbecues when people move.
Moving piles of firewood between locations is another way they can spread.
B.C. is committed to keeping the gypsy moth from becoming entrenched in the province.
Failure to stop their advance could result in the U.S. tightening trade restrictions against Canada.
Ebata said he believes the Cloverdale infestation will prove to be another “blip” that will be controlled.
“The size of the infestation is manageable,” he said. “We have a high probability of success in eradicating it.”
B.C. has battled and beaten bigger gypsy moth outbreaks before.
The worst was in 1998 in the western communities of Victoria when more than 500 moths were found, resulting in aerial spraying of 13,000 hectares.
Ebata said the infestation on 64 Avenue is a major concern, however, because of the heavy vehicle traffic through the area.
“The potential for this thing to spread out of there is very high,” he said. “So the urgency to deal with it is quite high.”
In 2013, pheromone traps caught single gypsy moths at sites in Surrey, Langley, Richmond, New Westminster, Shawnigan Lake on Vancouver Island and at McCleese Lake in the Interior.
The hairy caterpillar of the European gypsy moth devours the vegetation of many types of trees and shrubs. Province of Ontario photo.