If you had ‘moth invasion’ on your 2020 disaster bingo card, congratulations!
Residents of the New Denver area have been putting up with swarms of tiny, cream-coloured moths for weeks now.
“Typically, right now we are seeing western hemlock looper (Lamdina fiscellaria lugubrosa) or phantom hemlock looper (Nepytia phantasmaria), which are both native defoliators,” says Darcie Quamme, the senior biologist with Integrated Ecological Research in Nelson.
The bugs are after one of New Denver’s signature trees.
“The moths prefer western hemlock trees but sometimes outbreaks are seen on other hosts including Douglas fir,” says Quamme.
And it’s not just Slocan Lake that is seeing the large numbers.
“There have been a number of reports of moths from citizen-scientists and professionals, in particular, from the Kootenays, Kamloops and the Thompson-Okanagan area, the Lower Mainland and Sunshine coast,” she says.
The swarm of moths have been getting into every nook and cranny of people’s homes, outside buildings, and even on the water. An eclipse that landed in Rosebery Bay on Slocan Lake in August prompted a feeding frenzy for fish, one local resident reported.
While it’s not seen very often, mass invasions aren’t unnatural, says Quamme.
“Outbreaks occur approximately every 10 years and last about three years,” she says. “Recent droughts and a lack of soil moisture in the last few years may make forest stands more susceptible to the larvae.
“The moths prefer western hemlock trees but sometimes outbreaks are seen on other hosts including Douglas fir. Other host species at peak populations may also include: western red cedar, subalpine fir, amabilis fir, grand fir and spruce, native maples and forest understory vegetation.”
Outbreaks of these moths are naturally cyclic in British Columbia and not harmful to humans, says Quamme. She notes forest practices, which promote stand-health and maintain wildlife features that encourage the predators of moths – including bats, insects, birds and parasitoids – improve a stand’s resilience to the caterpillar attack.
There’s not much you can do about the moths, but live with it while it lasts.
“Generally, outbreaks are eruptive,” she says. “They spike quickly and crash just as fast in an explosive manner.”
It still beats murder hornets.
– Valley Voice