Moth infestation casts pall on Alaska berry crop

This year's blueberry season in Alaska's most populous region is a bust, thanks to a plethora of leaf-eating caterpillars, Alaska pest management officials said.

A multi-year infestation of geometrid moths appears to be peaking in the south-central region of Alaska, which includes Anchorage, according to a mid-summer advisory issued by the University of Alaska Fairbanks Cooperative Extension Service.

Michael Rasy, statewide integrated pest management technician for the
University of Alaska Fairbanks Cooperative Extension Service, said the outbreak was first reported in 2009 on the southern Kenai Peninsula. The most severely affected areas this year include Eagle River, around Summit Lake on the Kenai Peninsula, and near Homer and Seward, where hundreds of trees have been defoliated. The culprits have been identified as the Bruce spanworm and the autumnal moth, which are both geometrid moths.

The moths, in caterpillar form, have munched blueberry bushes to the
point where they cannot bear fruit this year, the extension service said.

Rasy said the blueberry and salmonberry crops have has been affected in some areas on the Kenai Peninsula and around Anchorage. Bushes in a favorite spot off Hiland Drive and Arctic Valley Road near Eagle River have been denuded.

“There’s just nothing there,” he said. “Everything is brown and bare.”

In the Mat-Su area, willow, birch and high-elevation shrubs have been
especially affected, and on the Kenai Peninsula and elsewhere, alder, berries and hardwood species have been damaged.

The moth infestation, and resulting poor berry growth, is reported in the state's southeast panhandle as well, the extension service said.

Berry pickers have reported their disappointing findings, said Corlene Rose, integrated pest management program director at the extension service.

It is not just the blueberry crop that is suffering. The caterpillars have defoliated bushes that would normally be bearing ripe salmonberries (left), a raspberry-type fruit, and denuded willows, alders and birch trees, the extension service said.

Even though the plants munched by the caterpillars lack many of their leaves and berries, they are most likely not dead and are expected to recover once the infestation is over, the extension service added. The defoliated plants look dead, but most will likely survive, said Rasy. Usually it takes several years of continuous defoliation to kill native deciduous trees, shrubs and berries.

Blueberry picking is a common summer ritual in Alaska. Berries are baked into pies, preserved for long winters and, in Native villages, mixed with animal fat or fish oil to create a sweet delicacy called akutaq.

Bears depend on berries, too, so Alaskans might expect additional raids this fall by bears on trash cans and fish scraps, one state biologist said.

"I do not think we'll see dramatic impacts to the local bears but I do think we'll see bears searching for food in more urban areas because of the lack of berries," Ryan Scott, an Alaska Department of Fish and Game
biologist, said in an e-mail.

Despite this year's poor blueberry
crop, business was brisk this weekend at the Alyeska Blueberry Festival in the ski community of Girdwood, about 35 miles south of Anchorage.

Resort chefs served specialty dishes such as blueberry salad (left), salmon with blueberry sauce and blueberry parfait (lower right). Vendors at booths had more down-home blueberry items for sale, and bucket-toting visitors managed to find some blueberries on bushes near the ski lifts.

Dinah Merrill, a Girdwood local selling blueberry cobbler, blueberry muffins and blueberry lemonade (left), said she could
tell that this year's wild crop was not very good.

"I notice that some of the spots we go to are not doing so well," said Merrill, who admits that she depends on store-bought blueberries for many of her goods. "But we have good years and bad years."


Reuters,"Moth infestation casts pall on Alaska berry crop", by Yereth Rosen, accessed August 16, 2011

UAF News, "Moth outbreak results in defoliation", accessed August 16, 2011


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