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PUBLISHED: 1:46 PM on Wednesday, June 7, 2006
Invasive species
Bugs are back for the summer, some are new to Alaska

  Photo courtesy of the U.S. Forest Service The insect spruce aphid attacks needles on Sitka spruce and cause defoliation on coastlines.
You're not the only one around town this summer.

Rising temperatures mean more bugs.

Some are beautiful. Some bite.

Others are new - and dangerous - to Alaska.

The mosquitoes began hatching in May.

The bumblebees and bald-faced wasps are back at work, too.

Dragonflies hit the airways en masse later in the season.

They are the state's official insect, and Alaska boasts 32 species.

Representatives of more than half of these species spend summers in Juneau. In emerald, azure and silver these diaphanous winged creatures dart around Juneau's bogs.

Spaulding Meadows - thanks to its necklace of ponds - is among the best place to see dragonflies, according to John Hudson and Bob Armstrong, authors of "Dragonflies of Alaska."

This year, entomologists expect an exotic European invader to strike Juneau.

Its arrival is a local example of a worldwide problem: invasive species that can cause billions of dollars in damage and permanent changes to local ecosystems.

Until recently Alaska escaped serious invasions from foreign species-thanks to its rugged terrain and sparse population.

European underwing yellow moths sport a drab wing coat of brown or gray, which hides a stunning pair of deep yellow wings, fringed in black.

These moths hit Nova Scotia in 1979. Traveling about 400 miles a year, they spent the next 20 years spreading across the United States.

By 2000, they had invaded Washington state. Last year they appeared in Southeast Alaska, said James Kruse, butterfly expert and entomologist with the U.S. Forest Service in Fairbanks.

"Last summer we had two suspected sitings in Juneau, but the moths appeared in Saint Lazaria, outside of Sitka, in huge numbers," he said.

They also were found in Haines and Skagway.

European yellow underwings eat dandelions and grass, but they also like garden vegetables such as broccoli and cultivated flowers such as chrysanthemums.

They multiply quickly. One entomologist in Connecticut, where they were first sighted in 1993, calls them drunken bombers and said they're everywhere.

Kruse, formerly curator of entomology at the University of Alaska Museum in Fairbanks, said it's unclear if these moths will present danger to native ecology.

"They appear to be an agricultural pest," he said.

Kruse estimates there may be as many as 1,000 species of native moths in Alaska, and only a few hundred identified. He says there are more than 80 species of indigenous butterflies.

In Juneau, butterflies and moths spend much of June as leaf-eating caterpillars. By July, they reinvent themselves as winged creatures.

European yellow underwings aren't the only invasive insect expected to hit Southeast Alaska this summer.

Amber-marked birch leaf miner plagues urban areas and forests throughout south-central Alaska. Since the bug's introduction to the state in 2002, it has spread from Anchorage to the Kenai Peninsula and north to Talkeetna.

In early spring black adult flies, which look like common flies, drop larvae on new leaves. The worm-like maggots feed between leaf surfaces and create blotchy kidney shaped areas. It's not until mid-July or August that their impact becomes obvious--leaves on infested birch trees turn totally brown.

Last year larvae were found feasting on the innards of birch leaves in Skagway and Haines. In 2004, the U.S. Forest Service, in conjunction with other government agencies and municipalities introduced a biological control program-a tiny wasp that feeds on birch leaf miners-that appears to be curtailing the spread.

Spruce aphid defoliation almost doubled last year in Southeast Alaska.

The aphids attack the older needles on Sitka spruce and like trees along coastlines.

They decimated the western and southwestern beach fringes of Prince of Wales Island last year.

Over time an infested tree will brown from the bottom to top and its needles with thin. The damage these little green pests with large red eyes can do becomes apparent in early spring, particularly after warm winters. In early summer, after decimating one tree, these aphids move to new coniferous conquests.

In the Skagway river watershed, the Western balsam bark beetle killed some 785 acres of sub alpine fir in 2005. The beetles dig nuptial chambers beneath bark and leave a lesion-causing fungus in these holes.

The fungus is particularly damaging and can kill trees, long after beetles are gone. The damage to Skagway's balsams last year was far worse than earlier years.


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