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Aphidinae : Macrosiphini : Pterocomma populifoliae
 

 

Pterocomma populifoliae

Grey-pink poplar bark aphid

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

Identification & Distribution

Adult apterae of Pterocomma populifoliae (see first picture below) are pinkish to brown, variably dusted with greyish wax, and with pale to dusky orange siphunculi. Their antennal and median frontal tubercles are poorly developed. There are usually some secondary rhinaria (0-25) on antennal segment III, but none on other segments (cf. Pterocomma bicolor, which has no secondary rhinaria on antennal segment III). The rostrum extends nearly to the hind coxae. Abdominal tergites II-VII normally each have a pair of conical marginal tubercles that are somewhat smaller than the tubercles on the pronotum. The siphunculi have a well developed flange, and are cylindrical to weakly-swollen on apical half (cf. Pterocomma smithiae, whose siphunculi are normally swollen on the basal half). The siphunculi have dispersed imbrication in addition to the normal subapical striae (cf. Pterocomma bicolor which has no such imbrication on the siphunculi). The cauda and anal plate are rounded. The body length of adult Pterocomma populifoliae apterae is 2.2-3.8 mm.

Note: Richards (1967) emphasises the risk of confusing this species with Pterocomma bicolor, which it closely resembles. The key diagnostic characters for Pterocomma populifoliae are presence of secondary rhinaria on antennal segment III, and presence of dispersed imbrications on the siphunculi. The colour difference is not considered a reliable diagnostic character.

Images above copyright Whitney Cranshaw under a Creative Commons Attribution 3.0 License.

Pterocomma populifoliae alatae (not pictured) are grey to light brown with a series of paired, median dorsal wax-dusted spots. The wax-dusted spots are also present in immature alatae (see second picture above). Siphunculi of the alate are pale, yellowish to dusky yellow. The abdomen has brown marginal sclerites, usually with paired median dorsal sclerites on segments II-VIII, with the pairs on segments VII and VIII sometimes fused to give bands.

Pterocomma populifoliae is found on poplar/aspen (Populus spp.), especially balsam poplar (Populus balsamifera), bigtooth aspen (Populus grandidentata), and quaking aspen (Populus tremuloides). It commonly colonises the roots or at bases of stems of young trees. The species is holocyclic, with oviparae and alate males occurring in September. It is found in north-eastern USA and Canada.

 

Other aphids on the same host

Pterocomma populifoliae has been recorded on 4 poplar species (Populus angustifolia, Populus balsamifera, Populus grandidentata, Populus tremuloides).

Acknowledgements

We are grateful to Whitney Cranshaw, for making his images of Pterocomma populifoliae available for use under creative commons licences.

We have used the keys and species accounts of Richards (1967), together with information from Roger Blackman & Victor Eastop in Aphids on Worlds Plants. We fully acknowledge these authors 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

  • Richards, W.R. (1967). The Pterocomma of Canada and Greenland with notes on the phyletic position of the Pterocommatini (Homoptera: Aphididae). The Canadian Entomologist 99(10), 1015-1040. Abstract