yukon wildlife in miniature tiger moths and woolly bears

Everybody loves butterflies, but what about moths? They're furry, and they invade the house on a summer's night to flutter maddeningly around the lights.

By Claire Eamer

Everybody loves butterflies, but what about moths? They’re furry, and they invade the house on a summer’s night to flutter maddeningly around the lights. Probably the most common reaction to moths is, “Ew!”

But there’s more to moths than a household annoyance. They’re far more diverse than butterflies and, often, just as beautiful. Moths fascinate Whitehorse entomologists Syd Cannings and Andre Langlois. In fact, they want to find more moths – especially tiger moths.

So far, more than 24 species of tiger moths have been identified in the Yukon, says Cannings. Eleven are Beringian survivors, species that are restricted to the area that remained ice-free during the last glaciation. Four of the species have been found only in the Yukon. And that might be just the beginning, Cannings says. “We’re finding more all the time.”

The pair put together a presentation about tiger moths for the recent Yukon Biodiversity Forum, in the hope of convincing more people to keep watch for the insects.

Tiger moths are generally about the size of most Yukon butterflies or a little smaller, says Cannings. Beyond that, it’s hard to pick out a common characteristic.

“Some of them have the obvious bright ‘tiger’ coloration on both the front and hind wings, or just the hind wings, and many have bold stripes or blobs on a contrasting background, even if they aren’t bright coloured. Some are just remarkably dull!” he says. “What they don’t have is the intricate camouflage patterns of most other moths – that’s a real key character that I notice.”

They’re actually easier to spot as caterpillars. Tiger moth caterpillars are called woolly bears, with reason. They are covered with long, bristly hairs, often bright orange or yellow, or even in stripes. They look almost cuddly – but they aren’t. In fact, some people are allergic to the hairs so it’s best to handle with care.

“Woolly bears are growing up in late summer and would be most obvious at the end of summer and in the following spring,” Cannings says. Not all hairy caterpillars are tiger moths, but most are closely related to them.

The adult moths are active in early summer, roughly from mid-June to mid-July. And you might find one species or another almost anywhere in the Yukon.

Around Whitehorse, the St. Lawrence Tiger Moth is fairly easy to find. It’s one of the flashier tiger moths. Its front wings are usually brown with white or pale splotches. The hind wings are deep yellow with black patches or stripes.

In the taiga region of the central Yukon, you might – if you’re lucky – find the Nebulous Tiger Moth, a Beringian species. It’s much less gaudy than the St. Lawrence Tiger Moth. The front wings are soft brown with irregular pale patches, and the hind wings are a sort of washed-out combination of the same colours. So far only a few specimens have been found in the Yukon – at Windy Pass, in the Richardson Mountains, and in the Blackstone River valley – but the moth has been found farther west within Beringia, in Alaska and Siberia.

Some of the tiger moths of particular interest to Cannings and Langlois are even less common, and very little is known about their lives and behaviour. Take, for example, the Kluane Tiger Moth. So far, only females have been spotted. No males or a caterpillars have been identified. The females have very short wings, so short that they apparently can’t fly until they lay their eggs and lighten their bodies. The Kluane Tiger Moth was discovered in 1989 and, until very recently, known from only two sites: Nickel Creek and Mount Archibald.

“News flash!” says Cannings. “This species was recently found – get this! – north of the Canol Road in the Northwest Territories. Just shows you how little we know!”

Even less is known about the Rockslide Tiger Moth. It was first found in 2005 at Mount Klotz, and a specimen was captured near Outpost Mountain in Kluane. Recently it has been found in the Richardson and Wernecke mountains too. It’s a small moth, mottled in black and grey, and it lives in the high, bare rocks of Yukon mountains.

A moth with a similar name, the Rockslide Lichen Moth, is one of the species Cannings calls “remarkably dull.” Its wings are greyish and almost translucent-looking, perfect for blending into the jumble of rock above the treeline, where the caterpillars survive on black rock lichen. Cannings says the moths are widespread on mountaintops in eastern Beringia, but nowhere else, as far as anyone knows. It doesn’t have any apparent close relatives. Indeed, a genetic study might be the only way to figure out where it fits in the tiger moth world.

Learning more about Yukon tiger moths isn’t just a job for experts, the entomologists say. Most of the moths and woolly bears can be identified from photographs, although a few specimens are always useful. And anyone can join the hunt.

“You need to get out there with cameras and nets,” Cannings says.

There are photos of adults of Yukon tiger moth species on the Noctuoidea of the Yukon webpage on the Canadian Biodiversity Information Facility website, www.cbif.gc.ca/spp_pages/noctuoidea/provinces/yt_e.php. Click on “Family Arctiidae.” For more information, or to arrange identification of photos or specimens, contact Syd Cannings at 335-6633.

This column is co-ordinated by the Northern Research Institute at Yukon College with major financial support from Environment Yukon and Yukon College. The articles are archived at www.taiga.net/yourYukon.