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Lachninae : Eulachnini : Cinara oregonensis
 

 

Cinara oregonensis

Pine cone aphid

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

Identification & Distribution

Available descriptions of this aphid of Cinara oregonensis are rather inadequate and sometimes conflicting. Wilson (1915) described adult apterae as shining brown, with the dorsum dusky to black, and (after mounting) with a dark black band from the base of the abdomen to the cauda. Palmer (1952) and subsequent authors described them as shining, light brick-red to rust-red. The images here show most apterae to be brick red with dusky pleural bands, but a few larger individuals (adults?) have the entire dorsum dusky to black (see dark aphid top of first picture below). The antennae are pale yellow with the apices of segments III-V and all of segment VI dark. The rostrum is long, reaching to the tip of the abdomen or slightly beyond. The abdomen has broad transverse sclerotized bars on tergites VII and VIII. The legs are mainly pale, but with knees, apices and distal two-thirds of the tibiae dusky. Hairs are fine, fairly numerous, erect, and on the tibiae are 1.5 times the tibial diameter. The siphuncular cones are black and rather small, each bearing 15-20 hairs. The cauda is rounded and dark. The body length of adult Cinara oregonensis apterae is 2.5-3.0 mm.

Images above copyright Ward Strong under a Creative Commons Attribution 3.0 License.

The alate viviparous female is dark brown to black; the abdomen has the dorsum of each segment black. Antennal segment III has about 3 to 6 irregular-sized round secondary rhinaria of medium size; segment IV has 1-2, and segment V has 2.

Cinara oregonensis is monoecious on lodgepole pine (Pinus contorta) and ponderosa pine (Pinus ponderosa). It has so far only been found living among scales of young cones, but Wilson (1915) suggested that this species may extend its feeding to the shoots later in the season. Palmer (1926, 1952), however noted that the second generation nearly all acquired wings and migrated to newly developed cones. In September-October oviparae and apterous males developed, and eggs were laid on the underside and at the bases of scales of cones. She found the species apparently rare, but abundant where occurring, noting they were difficult to detect on account of their protective coloration, unless their presence was betrayed by the attendant ants. The pine cone aphid is found in western USA and Canada.

 

Other aphids on the same host

Cinara oregonensis has been recorded on 2 pine species (Pinus contorta, Pinus ponderosa).

Acknowledgements

We are grateful to Ward Strong for making his images of Cinara oregonensis available for use under a creative commons licence.

We have used the species accounts and keys given by Wilson (1915) and Palmer (1926) (both as Lachnus oregonensis) and Palmer (1952), together with information from Roger Blackman & Victor Eastop in Aphids on Worlds Plants. We fully acknowledge these authors and those listed in the reference sections as the source for the (summarized) taxonomic information we have presented. Any errors in 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

  • Palmer, M.A. (1926). Life history studies of seven described species of the genus Lachnus. Annals of the Entomological Society of America 19(3), 300-330. (p. 311) Abstract

  • Palmer, M.A. (1952). Aphids of the Rocky Mountain Region: including primarily Colorado and Utah, but also bordering area composed of southern Wyoming, southeastern Idaho and northern New Mexico. Thomas Say Foundation, Denver. Full text

  • Wilson, H.F. (1915). Miscellaneous aphid notes, chiefly from Oregon. Transactions of the American Entomological Society 41(2), 85-108. (p. 103) Full text