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Chaitophorus ramicola

Sallow stem aphid

On this page: Identification & Distribution  Biology & Ecology  Other aphids on the same host 

Identification & Distribution

Adult apterae of Chaitophorus ramicola are broadly oval, mainly very dull greyish olive to black with a more-or-less distinct paler spinal stripe (see three largest grey or grey striped individuals in first picture below). The dark cross bands on abdominal tergites 1 and 2 are separate from 3, and tergites 3-6 may also have separate or only partially fused bands (cf. Chaitophorus capreae  which does not have darkened cross bands). The antennae and legs are dark. The fused 4th and 5th rostral segments are 1.0-1.3 times as long as the second hind tarsal segment. The body length of adult Chaitophorus ramicola apterae is 1.4-2.6 mm.

Images copyright Marco de Haas, all rights reserved.

Chaitophorus ramicola alates have narrow dorsal abdominal cross-bands.

Chaitophorus ramicola feeds on the thin stems of sallows (broad-leaved Salix species) such as great sallow (Salix caprea) and grey sallow (Salix cinerea) (cf. Chaitophorus salicti  which feeds on sallow leaves). Chaitophorus ramicola is usually attended by ants (see second picture above). Sexual forms (apterous males and oviparae) develop in October. The sallow stem aphid is found in north, central and eastern Europe, Iran and Kazakhstan.

 

Biology & Ecology

Ant attendance

Chaitophorus ramicola is unrecorded in Britain, so we are indebted to Marco de Haas for providing pictures of a colony he found in the central part of the Netherlands.

The colony was on sallow (Salix caprea) and was attended by jet black ants (Lasius fuliginosus).

Image copyright Marco de Haas, all rights reserved.

There have been only a few studies carried out on Chaitophorus ramicola, most notably by Iakovlev et al. (2017).  They studied the trophic position and seasonal changes in the diet of the red wood ant Formica aquilonia as indicated by stable isotope analysis. Most aphid colonies tended by Formica aquilonia belonged to four species. The aphid species Symydobius oblongus  and Chaitophorus populeti  were predominant from May to September, and Chaitophorus ? ramicola and Aphis fabae  were predominant from July to September. Honeydew collected from these four most common aphid species was probably a primary source of carbohydrate for Formica aquilonia during the summer. Tree-dwelling aphids such as Chaitophorus ramicola were found to be more important to red wood ants than grass-inhabiting aphid species like Aphis fabae.

 

Other aphids on same host:

Blackman & Eastop list over 120 species of aphids  as feeding on willows (Salix species) worldwide, and provide formal identification keys. Chaitophorus ramicola has not yet been found in Britain, so does not appear in the lists below.

Acknowledgements

We are especially grateful to Marco de Haas for the photos, which were taken in the central part of the Netherlands.

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).

Useful weblinks 

References

  • Iakovlev, I.K. et al. (2017). Trophic position and seasonal changes in the diet of the red wood ant Formica aquilonia as indicated by stable isotope analysis. Ecological Entomology 42(3), 263-272. Abstract