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Aphidinae : Macrosiphini : Epameibaphis atricornis
 

 

Epameibaphis atricornis

Dark knobbed-cornicle aphid

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

Identification & Distribution

Adult apterae of Epameibaphis atricornis (see first picture below) are brownish green, heavily dusted with grey-white wax powder, and with mainly black siphunculi, paler at the tips (cf. Epameibaphis frigidae and Epameibaphis utahensis, which have mainly pale siphunculi). They are dusky on the head and lateral areas on abdominal segments III-V, and there are two rows of dorsolateral spots and solid bands on tergites VII & VIII. The antennae are black except segments II and III, and bear no secondary rhinaria. Antennal tubercles are absent, and the vertex is nearly flat. Hairs on the body are blunt to capitate. The legs are black, except the front femora, which are dusky to pale (cf. Epameibaphis frigidae and Epameibaphis utahensis on Artemisia tridentata, which have pale legs). The siphunculi are mostly cylindrical, but with the flange swollen, so that the apex is knob-like (cf. all other aphid genera on Artemisia, none of which have knobbed siphunculi). The cauda is dusky and tapering. The body length of adult Epameibaphis atricornis apterae is 1.2-1.4 mm.

Both pictures above copyright Jesse Rorabaugh under a public domain licence (CC0).

The Epameibaphis atricornis alate (see clarified slide mount second picture below) has the head and thorax dark brown to black. The abdomen has dusky lateral areas, broken bands on abdominal segments I-V, and solid bands on tergites VII-VIII. The antennae (except the base of segment III), siphunculi and legs are black, excepting the anterior femora which are dusky to pale on anterior side. There are very few secondary rhinaria on the antennae, with up to 4 on segment III, and none on IV-V.

Both pictures above copyright Jesse Rorabaugh under a public domain licence (CC0).

Epameibaphis atricornis are monoecious on California sagebrush (Artemisia californica), long-leaved sage (Artemisia longifolia) and big sagebrush (Artemisia (= Seriphidium) tridentata). They are probably holocyclic, but sexual morphs have not yet been recorded. It is found in the western states of the USA.

 

Other aphids on the same host

Epameibaphis atricornis has only been recorded on 3 Artemisia species (Artemisia californica, Artemisia longifolia, Artemisia tridentata).

Acknowledgements

We are grateful to Jesse Rorabaugh for making his images of Epameibaphis atricornis available for use under a public domain licence.

We have used the species accounts given by Gillette & Palmer (1933) 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

  • Gillette, C.P. & Palmer, M.A. (1933). New species of aphids from Colorado. Annals of the Entomological Society of America 26(2), 348-367 (p. 348) Full text

  • 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