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Identification & Distribution

Adult apterae of Cinara laricifex (see first picture below) are black to dark brown to red-brown to bronze. There is wax-dusting ventrally and sometimes a little intersegmentally, but there is little or no wax on the dorsum (however see description of immatures below). Cleared specimens of Cinara laricifex can be readily distinguished from those of the other species feeding on Larix by the apparent lack of setae on the dorsum of the abdomen - setae are present, but are very short (0.02-0.03 mm) and are sited on small flat sclerites. The apical rostral segments (RIV+V) are usually less than 0.7 times longer than the second hind tarsal segment (HTII). The femora are mainly dark, although paler right at the base. The hind tibiae have most of the basal half pale, the pale section occupying at least 0.25 of the total tibia length (cf. Cinara laricifoliae which has the hind tibia mainly dark with a short pale section towards the base of length less than 0.2 of the total length of the tibia). The siphuncular cones are black. The body length of adult Cinara laricifex apterae is 2.5-3.5 mm. Immatures (see second and third pictures below) are variably waxed, with some fourth instars having extensive wax markings intersegmentally, lateral wax patches and a dorsal longitudinal white stripe.

Images above by permission, copyright Claude Pilon, all rights reserved.

The alate Cinara laricifex (shown as clarified slide mount below) is very dark in life, with long hairs, especially at the front of the head, the abdomen and the legs.

Images public domain from CBG Photography Group, Centre for Biodiversity Genomics(CC-0).

Note:
Cinara laricifex has been confused in the past with a Palaearctic species, Cinara laricis, (e.g. Kalman, 1954) - despite the fact that Cinara laricifex more closely resembles Cinara cuneomaculata, which has been found feeding on Larix laricina planted in Europe.

Cinara laricifex feeds on tamarack (Larix laricina). In springtime the fundatrices, which are dark brown often with a bronze lustre, occur singly or in groups of two or three. The second and subsequent generations occur in small colonies, consisting of a few females and their nymphs on new growth near the tips of twigs. Later they form colonies on the branches or trunk. Sexuales develop in autumn - the males are alate. The oviparae, which do not do not possess a pericaudal wax ring, attach their eggs to bark near the tips of the small branches. Cinara laricifex is found in Canada and the north-eastern USA.

 

Biology & Ecology

Cinara laricifex is very similar to a closely related species, Cinara laricifoliae (image not shown). Cinara laricifex lives east of the Rockies on Larix laricina, whilst Cinara laricifoliae lives on Larix occidentalis west of the Rockies in British Columbia. Bradley (1961) makes the point that, for allopatric (geographically isolated) populations, it cannot be assumed that they would be unable to breed together (i.e. reproductive isolation) as is the case of sympatric (living in the same location) species. The test used to decide the taxonomic status of such populations is inference, based on the degree of difference between similar sympatric species. Though similar in many respects, Cinara laricifex and Cinara laricifoliae exhibit morphological differences as great as those found between many sympatric species and are therefore considered to be true species.

Image above by permission, copyright Claude Pilon, all rights reserved.

As is common among Cinara species, Cinara laricifex populations are nearly always attended by ants (see picture below).

Image above by permission, copyright Claude Pilon, all rights reserved.

Bradley (1961) listed which species of ants attend the various Cinara species in Canada. Those recorded for Cinara laricifex are Formica fusca and an indeterminate Formica species.

Batulla & Robinson (1984) looked at the hymenopterous parasitoids of aphids in Manitoba. The only primary parasitoid attacking Cinara laricifex on Larix laricina was a Pauesia species. They also recorded the hyperparasitoid Dendrocerus from this aphid.

 

Other aphids on the same host

Cinara laricifex has only been recorded on one species of larch, tamarack (Larix laricina).

Blackman & Eastop list 7 aphid species of aphid as feeding on Larix laricina worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists 2 as occurring in Britain (Show British list).

 

Damage and control

We can find no reference to Cinara laricifex causing damage to larch trees.

Acknowledgements

We are especially grateful to Claude Pilon for pictures of Cinara laricifex (for more of his excellent pictures see, and, and).

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

  • Batulla, B.A. & Robinson, A.G. (1984). Hymenopterous parasitoids of aphids (Homoptera: Aphididae) in Manitoba.Proceedings of the Entomological Society of Manitoba 40, 30-38. Full text

  • Bradley, G.A. (1961). A study of the systematics and biology of aphids of the genus Cinara in Canada.PhD thesis, McGill University, Montreal, Canada. Full text

  • Kalman, Dale Archibald (1954). Forest Aphididae of Nova Scotia Full text