InfluentialPoints.com
Biology, images, analysis, design...
Aphids Find them How to ID AphidBlog
"It has long been an axiom of mine that the little things are infinitely the most important" (Sherlock Holmes)

 

 

Identification & Distribution

Adult apterae of Cinara nuda (in the first picture below, the two highly reflective dark brown aphids are adult) have the dorsal abdomen uniformly shiny dark brown with little or no wax, and without a pattern of dark markings (cf. Cinara pini  where the dorsum has a pattern of dark markings interspersed with a coating of pale grey wax). Dorsal abdominal hairs are short and sparse. The antennal terminal process bears 5-7 hairs between the apex and the primary rhinarium (cf. Cinara pini where the antennal terminal process bears 4 hairs between the apex and the primary rhinarium). The body length of the adult Cinara nuda aptera is 3.3-4.3 mm.

Alate Cinara nuda (see second picture above) also have the abdominal dorsum shiny, but with a little wax laterally and on the metanotum. The antennal terminal process is 0.040-0.055 mm long and bears 5-7 hairs between the apex and the primary rhinarium.

Cinara nuda is mainly found on Scots pine (Pinus sylvestris), but may also be found on mountain pine (Pinus mugo). It forms large ant-attended colonies on the trunk and on basal parts of older branches of young trees, or on 2- to 8-year-old parts of leading shoots of older trees. In summer smaller groups may be found under bark. Apterous males and oviparae have been found in central Europe in August to October and males have been found by us in England (see second micrograph above) as early as June. Cinara nuda is found over much of Europe and has also been found in China.

 

Biology & Ecology

Scheurer (1971)  provided a detailed account of population trends of Cinara nuda and its predators and parasitoids over three years. Overwintering eggs hatched from late March through April to give fundatrices which survived into June. In some years there was quite a high proportion of unfertilized eggs because of a shortage of males. The nymphs sat concentrically around the parent aphid for the first 4-5 days after birth, and then moved to find their own site. A high proportion of the first daughter generation was winged. Aphid numbers reached a peak in May/June before declining sharply as a result of emigration and predation by syrphid and coccinellid larvae and losses from a parasitic wasp. The high mobility of populations could explain their sudden mass appearance in certain pine groves. Aphid numbers then increased again in September when sexuales developed. Oviparae and males could be found up to the end of October or, in one year, into November.

All the colonies we have found have been attended by southern wood ants (Formica rufa, see pictures above and below).

We have not found this to be a common species, with all our observations coming from Flatropers Wood in East Sussex.

They also appeared to form mixed species colonies with Cinara pini, although the lack of adult apterae prevented confirmation of identification.

 

Other aphids on same host:

Blackman & Eastop list 30 species of aphid  as feeding on Scots pine (Pinus sylvestris) worldwide, and provide formal identification keys.

Of those aphid species, Baker (2015)  lists 15 as occurring in Britain: Cinara brauni,  Cinara nuda, Cinara pilosa, Cinara pinea,  Cinara pini,  Cinara pinihabitans, Essigella californica,  Eulachnus agilis,  Eulachnus brevipilosus,  Eulachnus rileyi,  Pineus orientalis, Pineus pini,  Pineus strobi, Prociphilus pini and Schizolachnus pineti. 

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

  • Scheurer, S. (1971). Biologische und ökologische Beobachtungen an auf Pinus lebenden Cinarinen im Bereich der Dübener Heide (DDR) während der Jahre 1965-1967. Hercynia N. F., Leipzig 8(2), 108-144. Full text