Project Description: (2016-04-15) This project includes observations about trees that may be infested by spruce aphids Elatobium abietinum. According to the Alaska Region U.S. Forest Service - Symptoms of spruce aphid infestation have been observed on the Kenai Peninsula. "The spruce aphid is a small green, soft-bodied insect about 1 to 1.5 mm in size. Both winged and wingless forms occur. Spruce aphids feed by inserting their needle-like mouth-parts into host foliage and sucking the sap from the needles. First symptoms of feeding are yellow patches on the needles. If the population increases, discoloration intensifies and affected needles turn brown and drop prematurely." USDA
Start Date: April 15, 2016
Project Lead: Pending
Observer Invite: In recognition of the expansion of spruce aphid in Alaska, the LEO Network is inviting observations about outbreaks of spruce aphids. Photos showing infected trees as well as close-ups of aphids on branches preferred.
Recognizing Spruce Aphid According to US Forest Service, "Spruce aphids are small (1/16 of an inch), soft-bodied, mostly
wingless insects. They are light green when young and turn an olive green when mature. Winged adults have two pairs of wings, with the front pair being much larger than the hind pair. Like other aphids the spruce aphid has sucking mouth parts which they use to suck the sap from foliage. They feed gregariously and secrete “honeydew” which attracts ants. Foliage damage appears similar to some needle cast diseases. The presence of the insect is necessary to identify spruce aphid as the
cause." Source: Management Guide for Spruce Aphid
Reference Materials:
Forest Health Conditions in Alaska - 2013 – Entomology Species Updates, Defoliating Insects, "A Forest Health Protection Report - Spruce Aphid: Little defoliation was attributed to spruce aphid during the 2013 aerial detection survey. A small amount of damage, totaling 158 acres, was found near the Petersburg Airport on Mitkof Island, across from the airport on Kupreanof Island, and near Tee Harbor in Juneau. Weather plays a major role in controlling aphid populations, which cannot survive long exposures to temperatures <15 F. Southeast Alaska experienced a moderate winter in 2013, with temperatures rarely falling below 15 F in some areas, yet little damage was recorded. Spruce aphids reproduce asexually, which contributes to sudden increases in activity when conditions are ideal. Large scale outbreaks of spruce aphid have occurred in Southeast Alaska following mild winters in 1992, 1998, and 2010. Spruce needle aphids feed on older needles of Sitka spruce; often causing significant needle drop (Figure 27). After a few years of defoliation, some trees retain only the most recent year or two of foliage. Spruce aphids usually favor the same trees year after year and outbreak after outbreak." Source: Spruce Aphid Elatobium abietinum (Walker), Status of Insects, page 24, USDA.
Sap-Sucking Insects, Gall Fromers and Mites – "Symptoms/Signs: The spruce aphid is a small green, soft-bodied insect about 1 to 1.5 mm in size. Both winged and wingless forms occur. Spruce aphids feed by inserting their needle-like mouthparts into host foliage and sucking the sap from the needles. First symptoms of feeding are yellow patches on the needles. If the population increases, discoloration intensifies and affected needles turn brown and drop prematurely." Source: Field Guide to Insects and Diseases of Arizona and New Mexico Forests, USFS
Spruce and Giant Conifer Aphids – "Aphids derive their nutrition from plants by piercing the tissues and sucking the juices from the needles. The spruce aphid prefers older needles and does not attack the new growth until late summer when the newest foliage hardens and begins to resemble the older needles." Source: Forest Service Leaflet R10-TP-96 August 2001, USDA
Media:
Alaska Dispatch News – (2016-05-25) New bug brings back memories of spruce bark beetle devastation, "CHINA POOT BAY – It looks like the start of the spruce bark beetle kill of the 1990s, when mountainsides across the Kenai Peninsula turned gray, the biggest tree blight in North American history to that time. But it started just last year." Author: Charles Wohlforth
KTUU News 2 – (2017-06-12) Aphids bug Anchorage gardeners, "Jessie Moan, an entomologist with the UAF Cooperative Extension Service, said aphids can be "site specific" to sections of town or neighborhoods. So far she said researchers have not seen a large-scale outbreak of aphids this spring." By Mike Ross