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:

In life, apterae of Cinara pruinosa are brown or dark green, sometimes with a bronze metallic tinge. They may or may not be wax-powdered along the sides of the dorsum and on the underside of the body (see pictures below), apparently depending on whether or not they are ant-attended. The adults of Cinara pruinosa usually have blotchy blackish markings in a pattern resembling the letter omega (Ω) on tergites 1-3. The legs are conspicuously hairy, with long hairs on the outer side of the hind tibia, all or many of the hairs exceeding 0.12 mm (cf. Cinara piceicola  which has only short hairs on the outer side of the hind tibia - less than 0.12 mm long). The tibiae are pale except for the apical one third of the femora, and the bases and distal halves of the tibiae and tarsi. The second tarsal segment is shorter than the maximum diameter of the cones. The two terminal segments of the rostrum are 1.1-1.5 times longer than the second tarsal segment. Cinara pruinosa adults have prominent black siphuncular cones (cf. Cinara piceicola  which have usually small and rather faintly pigmented siphuncular cones.) The body length is 2.4-5.0 mm.

The alate (see first picture below) is brown or green with a pattern of white wax spots down the midline and along the sides of the dorsum. Cinara pruinosa can form very large colonies on the shaded side of spruce branches (see second picture below).

The micrographs below show dorsal and ventral views of an apterous adult of Cinara pruinosa in alcohol. Note the long hairs on the legs and the prominent black siphuncular cones.

Oviparae are somewhat smaller than the viviparae and have a pericaudal wax ring (see picture below in life cycle section). Both alate and apterous males have been recorded (the latter possibly in error).

Cinara pruinosa occurs in small colonies on the woody twigs of Spruce (Picea spp.) in spring, but later found at base of trunk and on roots in ant shelters. Oviparae and alate males occur in September-October, but anholocyclic overwintering on roots also occurs. Cinara pruinosa is found throughout most of Europe eastward to Turkey, and in North America (where it is often recorded as Cinara palmerae).


Biology & Ecology:

Life cycle

Cinara pruinosa usually overwinters as eggs which are are laid on the bark of younger twigs. Pintera (1966)  reports that some apterae overwinter on the roots in chambers specially prepared by ants.

We have found thriving colonies of Cinara pruinosa as early as March (see picture below).

Carter & Maslen (1982)  report that alates (see picture below ) occur from June till August, and that their progeny develop on roots or the base of the trunk of spruce trees.

Oviparae with pericaudal wax rings (see picture below) and alate males with prominent black genitalia can be found in October and November.

We have already noted the two colour forms of Cinara pruinosa. We have found the green form (see below) somewhat less common than the brown form.

The ground colour is sometimes yellowish or gold rather than green as shown below.

Competition / coexistence

Cinara pruinosa often lives in close association with another species of spruce aphid, Cinara piceicola, sharing feeding sites. The picture below on the left shows a Cinara pruinosa (the aphid with the prominent black siphuncular cones) with an ovipara (with pericaudal wax ring) and two apterae of Cinara piceicola on spruce in October.

Each species is thought to benefit in this type of association with the group of aphids creating a feeding sink which increases the flow of nutrient to that part of the plant.

Ant attendance

We have sometimes found Cinara pruinosa to be attended by southern wood ants (Formica rufa) as can be seen in the pictures below. Binazzi & Scheurer (2009)  reported that Cinara pruinosa is optionally dependent on ants.

These immatures were taken from an ant-attended colony and had no wax dorsally. They were reared through to adults without the accompanying ants to check identification. These adults developed the 'typical' wax markings of Cinara pruinosa shown in the identification section (above top left).


It therefore appears that either Cinara pruinosa only develops its wax coating if it is not being attended by ants, or that the ants remove any wax coating that is produced. This would imply that the wax is primarily for defense against predators, with unwaxed colonies being defended by the ants.

In Sweden mixed populations of Cinara piceicola and Cinara pruinosa are attended by the wood ant Formica aquilonia. Johansson & Gibb (2012)  compared clear-cuts (leaving 5-10 trees/ ha), middle-aged and mature spruce-dominated stands of boreal forest for the quality and quantity of aphid honeydew obtained by these ants. Wood ants harvested less honeydew in clear-cuts which contributed to a reduction in size and abundance of wood ant workers and mounds.

The pictures below show what happens if Cinara pruinosa is not attended by ants. The only unattended colony we have found appeared quite different with heavy wax powdering of all the colony - to such an extent that we originally misidentified the colony below as belonging to another species, namely Cinara costata.  This picture shows a group of fourth instar nymphs.

The picture below shows an adult aptera from the unattended colony.


Natural enemies

Where Cinara pruinosa is attended by ants we have found neither predators nor parasites. Where it was unattended, we found potential predators present near the aphid colonies - specifically of the larch ladybird (Aphidecta obliterata) shown below.

When Aphidecta was put on a branch with aphids, it rapidly started devouring them. This does not prove that it is an important or even frequent predator, but it certainly shows that it will eat them when hungry!

The other predator we have found is the larva of a species of Syrphidae - possibly a Didea species.


Other aphids on same host:

Blackman & Eastop list about 170 species of aphids  as feeding on spruces (Picea) worldwide, and provide formal identification keys.

Of the 28 aphid species Blackman & Eastop list as feeding on Norwegian spruce (Picea abies) Baker (2015)  lists 16 as occurring in Britain: Adelges abietis,  Adelges laricis,  Adelges nordmannianae, Adelges viridis, Cinara costata,  Cinara piceae,  Cinara piceicola,  Cinara pilicornis,  Cinara pruinosa, Elatobium abietinum,  Pachypappa tremulae,  Pachypappella lactea, Pineus cembrae, Pineus orientalis, Pineus pineoides, and Prociphilus xylostei.


Damage and control

There is some evidence that populations respond favourably to use of fertilizer in nursery spruce trees. Wellenstein (1960)  reported that when 5-year-old potted Spruce, artificially infected with Cinara pruinosa, were fertilized with nitrogen, calcium, potassium, phosphorus, or trace elements, aphid populations on nitrogen and calcium-fed plants increased rapidly and then quickly declined. On potassium and phosphorus-fed plants the increase was slower, but greater and more lasting.

These mixed species colonies are usually ant-attended so one needs to assess the effect on growth of having both the aphids and the ants. Usually the growth of deciduous trees responds positively to wood ant - aphid mutualism as the ants destroy many harmful herbivores. In contrast, wood ant-aphid mutualism has been shown to suppress the growth of Scots pine. This may be because unlike deciduous trees, conifers have relatively few defoliating insects. Kilpelainen (2003)  found that wood ant-aphid mutualism was associated with a clear positive but non-significant  height growth response in individual 5-year-old Norway spruce seedlings, but had a small significant negative effect on the stem growth of individual fast-growing 30-year-old Norway spruces. They concluded that effects at the stand level were negligible, because only a small number of trees were heavily infested.


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 


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

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

  •  Johansson, T. & Gibb, H. (2012). Forestry alters foraging efficiency and crop contents of aphid-tending red wood ants, Formica aquilonia. PLoS ONE 7(3):e32817.  Full text 

  •  Kilpelainen, J. et al. (2009). Does the mutualism between wood ants (Formica rufa group) and Cinara aphids affect Norway spruce growth? Forest Ecology and Management 257 238-243. Abstract 

  •  Pintera, A. (1966). Revision of the genus Cinara Curt. (Aphidoidea, Lachnidae) in Middle Europe. Acta entomologica bohemoslavika 63, 281-321.

  •  Wellenstein, G. (1960). Ergebnisse vierjahriger Untersuchungen uber die Steigerung der Waldbienentracht. (Four years' results of trials to increase the honey harvest from the forest.) Zeitschrift fur Angewandte Entomologie 47(1), 32-41.