Green spruce aphid,
Elatobium abietinum,
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Fig. 55
Green spruce aphids feeding on the underside of needles. |
Fig.
56
Crown discolouration resulting from green spruce aphid infestation. |
Fig. 57
Chlorotic mottling due to attack by green spruce aphid. |
Fig.
58
Severe needle drop after attack by green spruce aphid. |
Distribution: Throughout
coastal B.C. wherever Sitka spruce occurs. Believed to be
introduced from Europe.
Tree Species Attacked: Sitka spruce, Norway spruce, and blue spruce are preferred; other spruce species may also be attacked. All ages of trees are susceptible, though damage is most severe on immature
spruce.
Insect Description & Damage Symptoms: Nymphs or adult aphids are found on the lower surface of needles where they suck the sap. Old needles are preferred over current growth. Nymphs are wingless, oval, and green, and approximately 0.1 cm long. Adults may be winged or wingless, and are 0.2 cm long, but are otherwise similar in body shape and colour to nymphs. Adults have a yellow-green head and dull red eyes. Eggs are oval-shaped and are yellowish-red to brown or black. Foliage discolouration and defoliation are most noticeable in spring. Individual needles exhibit chlorotic mottling. Infested crowns turn a dull green to brownish
colour.
Damage: The nymphs feeding habits cause foliage discolouration and subsequent needle drop. Severe and extensive damage is occasionally reported on the Queen Charlotte Islands, particularly on trees growing along the shoreline. In other areas, infestations tend to be sporadic in nature and rarely affect more than several hundred trees. Trees are usually only partially defoliated and recover with some loss in growth rate. Complete defoliation and mortality occur occasionally.
Similar Damage: None, except frost from previous years if it kills older needles. |
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Contact Tim Ebata
if you have comments on the presentation of this information.
BC Ministry of Forests
Forest Practices Branch
P.O. Box 9513 Stn. Prov. Gov.
Victoria, BC
V8W 9C2
Section phone: (250) 387-8739
Section fax: (250) 387-2136
Last updated March 12, 2002 |