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Aphidinae : Macrosiphini : Capitophorus shepherdiae
 

 

Capitophorus shepherdiae

Buffaloberry oleaster aphid

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

Identification & Distribution

Adult apterae of Capitophorus shepherdiae (see first picture below) are pale yellowish green to greenish yellow, with short transverse intersegmental dashes and spots of darker green; the cauda and anal plate are pale, and the legs, antennae and siphunculi are pale basally, but dusky distally. The antennae of the apterae are 5-segmented, with the terminal process 2.0-2.8 times the base of the last antennal segment (cf. Capitophorus hippophaes, which has the terminal process 5.5-8.98 times the base of that segment). The rostrum is acute with the tip rather needlelike, reaching between the second and third pairs of coxae. The dorsal cuticle is conspicuously pitted, and bears 3 dorsolateral and 1 lateral row of capitate hairs set on tubercles. The siphunculi are distinctly swollen subapically on the inner side (cf. Capitophorus elaeagni and Capitophorus similis, which have the siphunculi cylindrical or tapering, or only very slightly swollen). The cauda is short and tapering to broadly spoon-shaped, not longer than the apical rostral segment (RIV+V) and bearing 5 hairs (cf. Capitophorus hippophaes & Capitophorus hudsonicus, which have the cauda much longer than RIV+V and bearing 6-9 hairs). The body length of adult Capitophorus shepherdiae apterae is 1.3-2.3 mm.

Images above copyright Andrew Jensen under a cc by-nc-sa licence

The alate vivipara of Capitophorus shepherdiae (see second picture above) has the head and thorax dark brown to blackish, and the abdomen light green with dusky markings on the lateral areas, 3 on each side, and a quadrate patch from tergites III to the center of VI. The antennae are blackish beyond the base of segment III, with 17-24 secondary rhinaria on segment III and 7-8 on segment IV. The siphunculi are dusky apically.

The primary host of Capitophorus shepherdiae is buffaloberry (Shepherdia argentea). Some aphids apparently persist on this host throughout the summer, but morphologically similar aphids have been found on ragweed (Ambrosia spp.) in California and Washington, so there may be partial host alternation (for more see Jensen in Aphidtrek). This has yet to be confirmed by transfer tests. Capitophorus shepherdiae is confined to western USA where Shepherdia is found.

 

Other aphids on the same host

Primary hosts

Capitophorus shepherdiae has been recorded on 1 species of buffaloberry (Shepherdia argentea).

Secondary hosts

Capitophorus shepherdiae has (provisionally) been recorded on 2 ragweed species (Ambrosia acanthicarpa, Ambrosia psilostachya).

Acknowledgements

We are grateful to Andrew Jensen for making his pictures available for use under creative commons licences.

We have used the keys and species accounts of Gillette & Bragg (1916), Palmer (1952) and Corpus-Raros & Cook (1974), along 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 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

  • Corpus-Raros, L. & Cook, E.F. (1974). A revision of North American Capitophorus Van der Goot and Pleotrichophorus Borner (Homoptera: Aphididae). Smithsonian Contributions to Zoology 156, 1-143. Full text

  • Gillette, C.P. & Bragg, L.C. (1916). Two new aphids, Capitophorus shepherdiae and Siphocoryne aquatica (Hem., Hom.). Entomological News 27, 445-448.

  • 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. Full text