Spruce Aphid (Elatobium abietinum) Damage
Observation: Symptoms of spruce aphid (Elatobium abietinum) damage on the east shore of Nuka Passage on the southern end of the Kenai Peninsula. I was not able to get on the ground to confirm the symptoms were caused by spruce aphids. The damage appears to be fairly recent taking place either this winter and spring (2016) or during 2015.
Resource:
Spruce Aphid, a Non-native Species, Continues to Spread Across Coastal Alaskan Forests – Briefing Paper, Technical Lead, Elizabeth Graham, Entomologist documents, "A notable expansion of its range has occurred over the last few years. Significant defoliation of Sitka spruce was found on the Kenai Peninsula and on the Kodiak Archipelago. The spruce aphid, is a non-native and invasive species that causes significant damage to Sitka spruce. It has been a persistent pest in Southeast Alaska since the 1960s. Spruce aphids actively feed in winter months and their populations are constrained by cold temperatures. Warming climate may be a contributing factor to the recent range expansion." Source: USDA Forest Service, Forest Health Protection, Juneau, AK
Spruce aphid damage mapped during aerial detection survey since 1987. Years with heavy aphid outbreaks are distinguished by color. Spruce aphids were confirmed on the Kenai Peninsula for the first time in 2015. (Courtesy of U.S. Forest Service)
Spruce Aphid Damage Nuka Passage (Photo by Nathan Lojewski)
Spruce aphids feeding on the needles of Sitka spruce. Feeding damage causes the needles to turn yellow, then brown, then fall off. (Courtesy of U.S. Forest Service)