Hot, dry summer could accelerate North Shore looper moth outbreak

North shore residents and visitors should brace themselves for the early arrival of a pest that has plagued the region's forests for the last two summers.

It’s believed that Metro Vancouver’s hot dry weather is accelerating the looper moth’s life cycle.

Most loopers are currently in caterpillar stage, eating their way through forests and turning swaths of hemlock, cedar and douglas fir trees a reddish-brown colour.

“There will be some areas where it’s more severe and more noticeable,” said provincial forest entomologist Jeanne Robert, who predicts the worst-hit areas could see 30 to 60 per cent of trees fall victim to the looper infestation.

“We will see some trees probably dying from being defoliated repeatedly,” Robert said.

Local resident Ryan Younger is concerned at the amount of damage the looper larvae are causing.

“It starts in the treetops and you can see red and dead treetops, and starting to brown out all the way down,” he said.

While it’s too late for this year, Younger would like to see the province launch an aerial spray program next spring to combat future looper moth infestations.

“We just can’t sit on our hands and watch and assess or the mountains will be completely red and dead,” said Younger.

Robert says there is a safe bacterial spray that targets the moth larvae.

“When we tend to use that particular treatment, though, is at the beginning of an outbreak that our trapping results indicate will be severe and widespread,” said Robert.

Because this summer is expected to be the culmination of a three-year breeding cycle, Robert says now is not the time for such a program.

“This particular outbreak, although it’s concerning and we are definitely monitoring keeping and eye on it, is not something that merits a spray program at this stage,” Robert said.

The looper moth outbreak was most severe in early September last year, but the moths could emerge from their cocoons in August this summer.

“Soon, within a few weeks, they will take flight and turn into moths and fly away and spread their devastation farther afield and lay their eggs for the next season,” said Younger.

He’s worried if nothing is done, the looper will keep decimating the forest.

“There is already going to be a lot of tree mortality, but if we take action, we can mitigate it a lot,” Younger said. “If we do nothing, I guarantee there will be a much larger scale die-off.”