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Alaska’s tough insects provide a lesson in life's resilience

Mike Dunham
A beetle with many names: spruce beetle, pincher bug, moose lice, these beetles lay eggs in dead or dying spruce trees. They do not feed on or harm living spruce trees (unlike the Spruce Bark Beetle, which killed millions of spruce on the Kenai Peninsula in the 1990s). Unlike mosquitoes, deer flies, and black flies, these beetles have no interest in biting people but they sometimes bite in defense.
Photo by Derek Sikes
Derek Sikes bug-hunting on Kasatochi Island
Photo by Steve Peek
The predatory rainbow beetle (Carabus vietinghoffi) has a classic Beringian distribution. It occurs widely throughout northern Asia and Alaska, with a few records from far western Canada. Being a wingless species, it disperses slowly and likely traveled on foot across the Bering Land Bridge. As one of the more handsome beetles in the Fairbanks area it is a memorable encounter for most who find it.
Photo by Derek Sikes

As Ray Troll sings, people feel a cuddly affection for big mammals that they don't extend to more distant branches of the evolutionary tree.

You want to save the wolves of course,

Yeah you wanna save the whales.

But what about the smallpox germs,

Or the slimy fish with all those scales,

The snakes, the spiders, the shrimp, the crab,

Don't they need lovin' too?

Charismatic Megafauna, you get all the love.

Not from Derek Sikes. The Curator of Insects and Associate Professor of Entomology -- bug science -- at the University of Alaska Museum of the North in Fairbanks has loved insects since his childhood days in Rhode Island.

"I was 5, maybe 4, watching ants swarm as they were getting ready to fly," he said. "I became so engrossed in watching them that I didn't notice they'd climbed into my clothing. When I ran into the house with ants spilling out of my pants it was probably a good indication that I was going to be an entomologist."

Sikes has pursued insects, arachnids and other assorted arthropods from Southeast to the Aleutians to the North Slope. He probably knows as much about Alaska's bugs as anyone. He'll be sharing some of that knowledge in a public talk at Campbell Creek Science Center on Jan. 22.

The title of his talk: "Charismatic Microfauna."

"I'll be speaking on topics of interest to me," he said, including the collective biomass of the billions of tiny animals in the state, which is more extensive than we may wish to think.

"It's often said that if you weighed all the mosquitoes in arctic Alaska it would weigh more than all the caribou," he said. "That's plausible, but I don't think anyone's actually gone out and got the data."

Alaska has about 30 species of mosquitoes and an estimated 8,000 species of land and freshwater animals belonging to the phylum Arthropoda. (The name means "jointed feet"; ocean-going members of the group include king crab.)

Worldwide, more than one million species, mostly insects, have been described by scientists and another 10,000 or more are "discovered" each year.

"The best estimates are a total of 8 to 12 million arthropod species, so we haven't even hit the halfway point in terms of documenting these very small animals," Sikes said.

Small, but numerous. One reference, "The Handy Biology Answer Book," claims "two out of every three organisms known on Earth are arthropods."

Alaska's numbers are only a sliver of the total. "Oregon has over 25,000 species of just insects," Sikes said. "Add in spiders and you probably have 30,000. That's the effect of the really harsh climate that we have."

Unlike birds, Alaska bugs don't migrate. They have to endure subzero temperatures that can beset large areas for months at a time.

But endure they do. Sikes cited one kind of moth can crawl around the North Slope as a caterpillar for seven years before earning its wings.

Some bugs burrow into the ground or huddle with an air pocket around them in snow. "It's warmer under the snow than above it," Sikes observed. Others dehydrate themselves or have developed a protein that works like antifreeze, "strategies" that keep fatal ice crystals from forming in their cells.

Mosquito eggs and larvae develop under ice in water that's usually very cold, but not frozen, a magnificently successful survival strategy, as most Alaskans will attest. But Sikes credits the buzzing nuisances with an important place in the ecosystem. "The larvae are an important food source for fish," he said. "Males are well-known pollinators -- and they don't drink blood. We should be thankful that none of the ones in Alaska transmit diseases to humans."

In fact, insects may be the most important animals around. "They're kind of like this glue in the food web," Sikes said. "They provide a huge food base for birds and other animals, and for plants. They pollinate, assist in decomposition, move fungus around.

"If all arthropods were to disappear overnight, the entire ecosystem would suddenly collapse."

Despite their vital role, bugs tend to stay in the background of human consciousness. "People notice the most attractive, the butterflies and dragonflies," Sikes said. "Or the scary ones: spiders, pests, yellow jackets. But if you add up everything in those two categories, it's just the tip of the iceberg. The majority fly under the radar."

If you were collect a random sample of insects in your yard on a summer day, the odds are high that most would be something you'd never noticed before.

"It's always funny to me when someone comes to us with a spider and says, 'I've lived in Alaska all my life and never seen this kind of spider,'" Sikes said. "Even entomologists who collect thousands of spiders around the state haven't seen most of the spiders we have up here, and we're always collecting. What we know is a very small piece of a very big pie."

The bigness of the bug pie is one thing that attracts Sikes to the field. It is increasingly rare for anyone to report a new species of megafauna -- a new kind of elephant or bear, tuna or crocodile.

"But one thing that's different about entomology is that there is so much more to discover," he said. "It's easier to make dramatic discoveries."

Just last year, for instance, Sikes and UAF student Jill Stockbridge published their description of a previously unknown flea-like critter, a species of snow scorpionfly found on Prince of Wales Island. It's not a scorpion and it doesn't fly and it isn't found in snow, "but that's the family name," Sikes explained. "They don't like it too hot. Where they're found in the Lower 48 they're most active in the spring when snow is melting. But they're active all summer long in Alaska where it's always cool."

In addition to finding new insects, Sikes follows the movements of some that are too well known -- like bed bugs.

"They're getting more and more common everywhere," he said. "In Alaska we've had a number of reports, even in the villages, where they become a real problem. You'd have to go back to the 1950s to see these kinds of numbers."

The resurgence is due to the success of pesticides some decades ago, he thinks. People quit using the pesticides when they quit seeing the bugs, figuring the job was done. In the meantime, some of the bugs became more resistant to the chemicals deployed to destroy them.

It's nothing new, Sikes said. "This species of insect has been living with humans as our unwelcomed guest since we were living in caves."

And they're good candidates to move with us into space. If survival of the fittest is an immutable law, few things are as fit as an Alaska arthropod. This reporter has watched a spider walking across snow at near zero temperatures. "People think of insects as being cold-blooded," Sikes said, "but they do make quite a bit of heat."

He recounted how science teacher Elizabeth Beks put a moose head in the woods behind the North Pole High School so that students could observe its decomposition. It was swarming with maggots when Sikes suggested they put a thermometer into the skull. The air temperature was in the 30s, but the inner temperature of the mass of maggots was nearly 100 degrees.

Even more surprising, Sikes said, was what he found on an island in the Aleutians. In 2008 Kasatochi Volcano, 60 miles west of Atka, buried the entire island in hot ash estimated to be 800 degrees Celsius, almost 1500 degrees Fahrenheit -- hot enough to melt plutonium.

When scientists approached the island as soon as they dared, Sikes expected to find the place as dead as the moon. "But there were quite a few survivors."

The ash may have fallen hotter or cooler in different places and some insects apparently survived in crevices or insulated by plant matter that was buried under the ash.

Seabirds have resumed nesting on the island, bringing with them nutrients from the ocean. Surviving arthropods are now rebuilding their numbers.

"There are already a couple of hot spots of diversity on the island," Sikes said. "It's a great lesson on the resilience of life."

Reach Mike Dunham at mdunham@adn.com or 257-4332.

 


By MIKE DUNHAM
mdunham@adn.com
Contact Mike Dunham at or on