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Aphididae : Aphidinae : Aphidini : Brachyunguis
 

 

Genus Brachyunguis

Waxy amaranth aphids

On this page: Brachyunguis tamaricis

Brachyunguis [Aphidini]

Brachyunguis aphids are usually grey or green and, apart from the North American species, are often coated with mealy wax. They are generally without body sclerotization, apart sometimes from darkening of the head, and the presence of small marginal sclerites on the thoracic tergites and separate sclerites on the 7-8th abdominal tergites. The clypeus is often globose, but the extent of its enlargement varies considerably. The antennal terminal process is usually shorter, but is occasionally equal to or slightly longer, than the base of the apical antennal segment. Secondary rhinaria are absent in the apterous viviparous females. In the majority of species the apical rostral segment is shorter than the second segment of hind tarsus; it is rarely equal to or a little longer than it. The first tarsal segments have 3:3:2 hairs. The siphunculi are very short, pale or rarely dark, and subcylindrical or conical. The cauda is conical, triangular, or finger-shaped, and is pale or dark, with 6-12 hairs. The genus has been divided into the subgenera Brachyunguis s. str. and Xerophilaphis, but the justification for this has been challenged (see Blackman in Aphids on World's Plants).

Brachyunguis has about 40 species which feed mostly on plants in the Amaranthaceae (= Chenopodiaceae), but have also been found on various other families including the Apiaceae, Asclepiadaceae, Asteraceae, Brassicaceae, Cuscutaceae, Pistaceae, Polygonaceae, Sapindaceae, Solanaceae and Zygophyllaceae. The species of Brachyunguis are distributed in arid regions of Southern Europe, Northern Africa, Asia, and America. Kadyrbekov (2001) gave a brief diagnosis of the genus in his description of xerobiont taxa from the subtribe Aphidina.

 

Brachyunguis tamaricis (Common tamarisk aphid)

Adult apterae of Brachyunguis tamaricis are light green with a reddish area around the siphuncular bases (see first picture below). They have a rather patchy coverage of light grey wax, which gives them a velvety grey-green appearance and obscures the reddish patches around the siphunculi. Their antennae are 5- or 6-segmented. When 6-segmented, antennal segment III is about as long as antennal segment VI or shorter (cf. Brachyunguis tamaricophilus which, when the antennae are 6-segmented, has antennal segment III much longer than segment VI). The apical rostral segment (R IV+V) is 0.6-0.75 times as long as the second hind tarsal segment (HT II) (cf. Brachyunguis tamaricophilus, for which R IV+V is 0.8-0.9 times the length of HT II). The siphunculi of Brachyunguis tamaricis are rather short, only 0.63-1.0 times as long as the cauda. The cauda is finger-like (cf. Brachyunguis tamaricophilus, which has a triangular cauda). The body length of adult Brachyunguis tamaricis apterae is 0.9-1.7 mm.

Images above copyright Dr László Érsek, all rights reserved.

The alate Brachyunguis tamaricis may be less heavily waxed than the aptera (see second picture above). They have 2-8 secondary rhinaria on antennal segment III, 0-2 on segment IV and 0-1 on segment V.

Brachyunguis tamaricis feed only on tamarisk (Tamarix species). Sexual forms (oviparae and apterous males) have been recorded in Europe (France & Portugal) in autumn. They may be attended by ants. Brachyunguis tamaricis occurs in south, central and eastern Europe (not in Britain), North Africa and south-west and central Asia.

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Acknowledgements

We have made provisional identifications from high resolution photos of living specimens, along with host plant identity. In the great majority of cases, identifications have been confirmed by microscopic examination of preserved specimens. We have used the keys and species accounts of Kadyrbekov (2001) along with Blackman & Eastop (1994) and Blackman & Eastop (2006) We fully acknowledge these authors 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).

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References

  • Kadyrbekov (2001). Contribution to the systematic of the xerobiont supraspecific taxa from subtribe Aphidina (Homoptera, Aphididae). Tethys Entomological Research 3, 89-98.