Dillingham sees spike in speckled green fruitworm moths

May 17, 2017

Pilot-biologist Kara Hilwig took it upon herself to identify the brown moth species that is flying all around the town and tundra.

Speckled green fruitworm moth
Credit Kara Hilwig/ Togiak National Wildlife Refuge

From the harbor to the top of Warehouse Mountain, Dillingham is seeing an abundance of furry, brown moths this spring. Kara Hilwig, pilot-biologist at the Togiak National Wildlife Refuge, heard from an area gardener in the fall that there were more caterpillars than usual. Come spring, now there are a lot of moths.

“These moth are everywhere. I see them flying outside my office window. I see them crossing the road. They’re clumped on the willow catkins. I see them lapping up the sap on all the birch and alder trees around town,” says Hilwig.

Alaska is home to hundreds of moth species, so she called in reinforcements to identify this particular moth that has showed up in force. Clifford Ferris, co-author of “Butterflies of Alaska,” identified the moth as a speckled green fruitworm moth.

Why there should be such a spike in these moths is still a mystery. However, now that they are here, they are likely to dine on the greenery in the area.

“Anytime you have an outbreak of any sort of leaf eating insect, there’s always a risk of things getting defoliated, so leaves are taken off of the trees. But also it’s a food source,” Hilwig says, explaining that the moths provide abundant nutrition for young birds.

Overall, Hilwig thinks it is unlikely the eruption of these moths signals any larger ecological change. Upsurges like these are intermittent and short lived, and the speckled green fruitworm moth population could return to normal numbers within a few years. 

Contact the author at avery@kdlg.org or 907-842-5281.

Credit Kara Hilwig/ Togiak National Wildlife Refuge