Spruce aphid

Elatobium abietinum (Walker) (Hemiptera: Aphidae)

Orientation to pest

Spruce aphid, Elatobium abietinum (Walker), (known as "green spruce aphid" in some places) is native to part of Europe, where it feed on Norway spruce (Picea abies [L.] H. Karst). It is seldom a pest on this species in Europe, causing only infrequent, very minor local outbreaks. However, it is a major pest in northwestern Europe in plantations of North American Sitka spruce (Picea sitchensis [Bong.] Carr. Outside of Europe, spruce aphid is invasive in many areas with maritime climates and also the montane forests of the southwestern United States. In North America, spruce aphid occurs in natural forests on various spruce species, mostly in coastal areas of the Pacific northwestern United States and British Columbia. It also occurs in Arizona, where spruce aphid outbreaks damage Engelmann spruce (Picea engelmannii Parry ex Engelm.), killing 10 to 24% of infested trees, depending on the severity of injury. In maritime areas, spruce aphid is parthenogenic (females only), but in its native range and in Arizona the life cycle includes both parthenogenic and sexual forms.

Hosts commonly attacked

Spruce aphid feeds on virtually all spruce, including Norway (P. abies), Sitka (P. sitchensis), Englemann (P. engelmannii), and Colorado blue spruce (Picea pungens Englmann).

Distribution

In addition, to its native range in Europe, this aphid has invaded parts of Russia, Australia, New Zealand, Chile, and North America. It is found in British Columbia, Ontario, Quebec, California, North Carolina, Oregon, Arizona, Utah, and Washington.

Images of spruce aphid

Donald Owen, California Department of Forestry and Fire Protection, Bugwood.org 768x512 / 1536x1024	Elizabeth Willhite, USDA Forest Service, Bugwood.org 768x512 / 1536x1024	Andris Eglitis, USDA Forest Service, Bugwood.org 768x512 / 1536x1024
Figure 1. Spruce aphid, Elatobium abietinum	Figure 2. Damage to Sitka spruce from spruce aphid	Figure 3. Stand of Sitka spruce in Alaska showing damage of spruce aphid (areas in brown)

Important biological control agents related to this pest species

Generalist predators of this species have been noted, but parasitoids have not been studied. Pathenogenic fungi, especially species of Entomophthorales, are important natural enemies of spruce aphid.

Web links for information on spruce aphid

• Fact Sheet | USDA Forest Service, Southwestern Region
  From Field Guide to Insects and Diseases of Arizona and New Mexico Forests
• Gardening Advice Fact Sheet | The Royal Horticultural Society, United Kingdom
• Forest Health Note | Oregon Department of Forestry FHP
  Resource for the non-industrial private forest landowner
• Research Summary for Improving Resistance | University of Ulster, Northern Ireland
  Includes photos of some natural enemies of the spruce aphid

Articles

• Straw, N. A., J. E. L. Timms, and S. R. Leather. 2009. Variation in the abundance of invertebrate predators of the green spruce aphid Elatobium abietinum (Walker) (Homoptera: Aphididae) along an altitudinal transect Elatobium abietinum. Forest Ecology and Management 258: 1-10.
• Lynch, A. M. 2004. Fate and characteristics of Picea damaged by Elatobium abietinum (Walker) (Homoptera: Aphididae) in the White Mountains of Arizona. Western North American Naturalist 64: 7-17.