Aerial spraying in Surrey and Delta last spring appears to have succeeded in eradicating an infestation of European gypsy moths.
Provincial government officials say just two moths have since been found in the 4,500-hectare Surrey spray zone around Cloverdale and Panorama Ridge, and no moths have been trapped in Delta, where 200 hectares was sprayed near where Highway 91 connects to highways 99 and 10.
About 200 moths had been trapped in the previous summer of 2014.
No further spraying is planned for 2016, according to forests ministry officials, but continued intensive trapping is planned around Surrey to determine what kind of treatment program may be needed in future years.
Helicopters sprayed treatment agent Foray 48B. It contains the naturally occurring bacteria Btk, which kills the fuzzy leaf-munching caterpillars before the larvae turn into adult moths.
The introduced moth is destructive to forests, orchards, farms and urban trees. Halting its advance is also considered important to avoid trade restrictions.
Some angry residents complained that they did not get enough advance warning of the spray program.
There were also claims of allergic reactions – unconfirmed by health officials – as well as local concern that other species such as butterflies and bees might be harmed.
It was the first time B.C. has sprayed to control gypsy moths since a 2010 infestation in Richmond.
Gypsy moth caterpillar. Nearly 200 male European gypsy moths were caught in pheromone traps last summer in Cloverdale on trees along 64 Avenue. Contributed.