Tent caterpillars, which last year wiped out apple crops on Saltspring Island and caused the cancellation of the annual apple festival, are now hatching from their tree-top nests and munching on fresh, green leaves.
But these new hatchlings aren’t expected to reach the numbers of last year, nor decimate fruit orchards or deciduous trees to the same extent.
“They’re really patchy,” said Judith Myers, a University of B.C. entomologist who studies the western tent caterpillars.
The population of hatching crawlers seems to be a bit above normal but the damage they are expected to cause will not be as bad as in the past, Myers said.
The numbers have plummeted in Myers’ main study sites. “We’ve been driving around Galiano today and we see very little evidence [of caterpillars],” Myers said.
“The tents are small and they’re not doing very well.”
But other areas of the south Island have trees, often alders and willow, dotted with tents where eggs are hatching and caterpillars are venturing out.
“There are quite a few caterpillars around,” Myers said.
“I was in Sidney last week, and alder trees had tents in them. Still, it’s very patchy.”
The main apple orchard on Saturna Island had very few caterpillars this year, she said.
There are reports of higher than normal numbers of tent caterpillars on the Lower Mainland this year. “They’re having more of an outbreak this year,” Myers said. “It’s like a wave that’s gone east from the Gulf Islands.”
Terry Michell, of Michell Bros. Farm on the Saanich Peninsula, said he’s seeing fewer tent caterpillars this year compared with last.
“Our orchard is pretty clean,” said Michell on Tuesday.
Last year, the insects “seemed to be all over,” he said, adding that friends in Nanaimo have reported high numbers of tent caterpillars there.
The caterpillars form cocoons and later emerge as moths looking to mate. The female lays all her eggs on a tree branch where they stay through the winter. The population can vary widely over a few years, fluctuating by more than a thousand-fold.
The best way to get rid of caterpillars is to remove affected branches from trees or spray them with a microbial spray, which isn’t harmful to humans or other insects.