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Genus Elatobium

Spruce & fir aphids

Species Overview: Genus Elatobium  Elatobium abietinum 

Genus Elatobium [Macrosiphini]

Small elongate-oval aphids the adult viviparae of which may be winged or wingless. Siphunculi are cylindrical, long, thin and pale, with a well developed apical flange. The cauda is pointed.

This genus comprises only 6 species which live on Spruce (Picea spp.), Fir (Abies spp) and some non-conifers. They are cryptic when feeding. Some species (and some populations within species) have retained a sexual stage in the life cycle, whilst others have lost it. They do not host alternate and are not attended by ants. One species is an important pest of spruce.

 

Elatobium abietinum (Green spruce aphid)

Apterae of Elatobium abietinum are pale to dark green, sometimes with a partial wax bloom giving the appearance of two darker green longitudinal stripes (see pictures below). The siphunculi are cylindrical, long, thin, pale and tend to be slightly s-curved. They are up to 2.5 times the length of the cauda which is pale and pointed. The body length of Elatobium abietinum apterae is 1.0-2.0 mm.

 

Elatobium abietinum spend all year on the needles of spruce, especially Sitka spruce (Picea sitchensis) and Norway spruce (Picea abies and, much less commonly fir (Abies spp.). The green spruce aphid has an unusual life cycle in that populations often continue to feed and reproduce through the winter. In spring and early summer alates are produced in response to the changing nutritional status of the host. They then migrate to other spruce where their nymphs aestivate for the summer before resuming development in autumn. The species is native to Europe, but it has now spread to Australia, New Zealand, Chile and North America. Populations in continental Europe have a sexual stage but elsewhere overwintering is by parthenogenetic forms.

Elatobium abietinum can be a serious forestry pest with colonies on spruce causing discoloration and loss of old needles, sometimes involving serious defoliation.

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Acknowledgements

We have made provisional identifications from high resolution photos of living specimens, along with host plant identity. In the great majority of cases, identifications have been confirmed by microscopic examination of preserved specimens. We have used the keys and species accounts of Blackman & Eastop (1994)  and Blackman & Eastop (2006)  supplemented with Blackman (1974) , Stroyan (1977) , Stroyan (1984) , Blackman & Eastop (1984) , Heie (1980-1995) , Dixon & Thieme (2007)  and Blackman (2010) . We fully acknowledge these authors as the source for the (summarized) taxonomic information we have presented. Any errors in identification or information are ours alone, and we would be very grateful for any corrections. For assistance on the terms used for aphid morphology we suggest the figure  provided by Blackman & Eastop (2006).

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