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Aphididae : Aphidinae : Macrosiphini : Epameibaphis


Genus Epameibaphis

Knobbed-cornicle aphids

On this page: Epameibaphis atricornis

Epameibaphis [Macrosiphini]

The genus Epameibaphis is related to Pseudoepameibaphis, Flabellomicrosiphum and the palaearctic genus Coloradoa. It was established by Oestlund (1922), and was reviewed by Knowlton & Smith (1936). The vertex is nearly flat. There are few, or no, secondary rhinaria on the apterae, but the alate has round rhinaria on segment III. They have the typical stiletto-shaped apical rostral segment of aphids feeding on Anthemideae. The hairs on the body are long, many of them blunt, enlarged, or flattened at their tip. The siphunculi are cylindrical with a conspicuous knob-shaped apex. The wing venation is as in the genus Aphis.

There are three species of Epameibaphis, monoecious on Artemisia and Seriphidium. They are most likely all holocyclic, and are found in the Western USA.


Epameibaphis atricornis (Dark knobbed-cornicle aphid) Western USA

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 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.

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.



We are grateful to Jesse Rorabaugh for putting his images in the public domain.

We have used the keys and species accounts of Knowlton & Smith (1936) together with those of Roger Blackman & Victor Eastop in Aphids on Worlds Plants. We fully acknowledge these authors (see references below) 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


  • Oestlund, O.W. (1922). Report of the State Entomologist of Minnesota 19 pp. 132-133.

  • Knowlton, C.F. & Smith, G.F. (1936). The aphid genus Epameibaphis in Utah. Proceedings of the Entomological Society of Washington 38(5), 89-91. Full text