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Identification & Distribution:

Apterae and alatae are darkish brown to orange-reddish, sometimes with dark green segmental markings. There is usually a dusting of greyish wax powder on the ventral surface of adults which may extend as stripes on to the dorsum of the abdomen. The siphuncular cones are small. The legs have the hind tibiae dark for up to two thirds their length; the femora are mostly dark brown but paler proximally. The body length is 2.4-4.6 mm.

 

The first image above shows an dark brown adult aptera on larch in July. Note the small siphuncular cones often surrounded by rather pale cuticle, and the lack of hair-bearing sclerites on abdominal tergites 2-6 (the latter distinguishes the species from Cinara laricis which occurs commonly on larch). The second image shows a more orange-brown aptera in October.

 

The images above are micrographs of dorsal and ventral views of an aptera in alcohol. Key distinguishing characteristics for this species are that the fourth rostral segment is from 0.15 to 0.25 mm in length, and that the fourth antennal segment is clearly longer than the sixth including the terminal process.

Oviparae have been reported to be dark brown with darker sclerotized blotches and no pericaudal wax ring (Carter & Maslen, 1982 ), but this does not agree with our observations as can be seen in the first image below. This shows a light reddish-brown ovipara with a marked pericaudal wax ring. They also reported that males were winged, whereas we have regularly found what appear to be brachypterous males.

 

They feed on young twigs and shoots of larch (Larix spp.). The egg laying females (oviparae) occur in October. They are found in Europe excluding Scandinavia and the Iberian peninsula; also in parts of Asia.

 

Biology & Ecology:

The eggs which were laid on larch the previous year hatch in spring to give the fundatrices (stem mothers). As with Cinara acutirostris, Buchholz & Scheurer (2000)  showed that a period of frost (-5 to -15°C) for several weeks produced a higher ratio of hatching fundatrices than a period of around 0°C temperature.

 

These two images taken in September and July shows groups of young nymphs feeding on the branches. As with many other species, they cluster together when feeding to create a sink effect which improves the flow of nutrients. As well as feeding in aggregations of its own species, Cinara cuneomaculata can often be found in multispecies aggregations.

The aphid in the centre of the picture above with a pericaudal wax ring is an ovipara of Cinara cuneomaculata, whilst the other aphids around the ovipara belong to a different species of larch aphid - Cinara laricis.

 

Binazzi & Scheurer (2009)  report that this species is independent from ant attendance, but we have found that ants are usually present. In the first picture above, taken in late August, a southern wood ant (Formica rufa) is stroking an old viviparous female to promote honeydew production. The copious honeydew crystallizes to Lärchenmanne which is highly regarded by beekeepers in central Europe. In the second image the ant has taken up its defensive posture with its abdomen swung forward ready to spray formic acid.

 

We have so far not observed any predation on this species (possibly because of protection by the ants), but at least one species of parasitoid is often present. The first image shows a parasitized aphid known as a 'mummy'. The adult braconid parasitoid which emerged from this mummy is shown in the second image. Identification is a little uncertain but it appears to be Pauesia pini, a species recorded as parasitizing both of the larch species of Cinara (Wiaçkowski et al., 2001. )

 

Damage and control

We are not aware of any work quantifying the effects of infestation by this species on the timber yield of larch, but it seems safe to assume that foresters regard this aphid as harmful, and beekepers see it as beneficial! Börner & Franz (1956) reported that dense 'overpopulated' colonies caused a local yellowing of the foliage.

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).

Useful weblinks 

References

  •  Binazzi, A. & Scheurer, S. (2009). Atlas of the honeydew producing conifer aphids of Europe. Aracne. 132 pp. Introduction 

  •  Blackman, R. L. & Eastop, V.F. (2006). Aphids on the World's Herbaceous Plants and Shrubs. Vols 1 & 2. J. Wiley & Sons, Chichester, UK. Full text 

  •  Dixon, A.F.G. & Thieme, T. (2007). Aphids on deciduous trees. Naturalist's Handbooks 29. Richmond

  •  Börner, C. & Franz, H. (1956). Die Blattläuse des Nordostalpengebietes und seines vorlandes. Ost. zool. Z. 6, 297-411.

  •  Buchholz, S. & Scheurer, S. (2000). The influence of the length of frosty periods on emergence of fundatrices of selected Cinarinae (Sternorrhyncha, Lachnidae). Entomologica Brasiliensia 22, 143-147. Abstract 

  •  Carter, C.R. & Maslen, N.R. (1982). Conifer Lachnids. Forestry Commission Bulletin No. 58, 75pp.

  •  Heie, O.E. (1980-1995). The Aphidoidea, Hemiptera, of Fennoscandia and Denmark. (Fauna Entomologica Scandinavica) E.J. Brill, London

  •  Stroyan, H.L.G. (1977). Homoptera: Aphidoidea (Part) - Chaitophoridae and Callaphidae. Handbooks for the identification of British insects. 2 (4a) Royal Entomological Society of London. Full text 

  •  Stroyan, H.L.G. (1984). Aphids - Pterocommatinae and Aphidinae (Aphidini). Handbooks for the identification of British insects. 2 (6) Royal Entomological Society of London.

  •  Wiaçkowski, S.K. et al. (2001). Aphid parasitoids (Hymenoptera: Aphididae) of Central and Southern Poland. Wiad. entomol. 20 (1-2), 57-65.Full text