Exallandra cinctifacies (Speiser)
Speiser (1910) described Syrphus cinctifacies from Tanzania. Vockeroth (1969), in his revision of the Syrphini, erected a new genus for this species, Exallandra.
Synonyms:
Syrphus cinctifacies Speiser, 1910: 119.
Speiser (1910) described Syrphus cinctifacies from Tanzania. Vockeroth (1969), in his revision of the Syrphini, erected a new genus for this species, Exallandra.
Synonyms:
Syrphus cinctifacies Speiser, 1910: 119.
Exallandra cinctifacies (Speiser, 1910).
Speiser, P. (1910) 5. Cyclorapha. Pp. 113-198. In: Sjostedt, Y. (ed.), Wissenschaftliche Ergebnisse der schwedischen zoologischen Expedition nach dem Kilimandjaro, dem Meru und den umgebenden Massaisteppen, Deutsch-Ostafrikas 1905-1906. P. Palmquists Aktiebolag, Stockholm. Vol. 2, part 10, 202 pp., 2 pls.
Very small slender dark species with small and rather variable yellow markings on thorax and abdomen.
In external structural characters, E. cinctifacies is extremely similar to the many species of Melangyna. However, the colour pattern and terminalia are strikingly different, and the reduction of the subscutellar fringe offers a convenient recognition character for both sexes. Generic separation of this species was reasonable for Vockeroth (1969). The distribution is disjunct from that of the typical and largest subgenus of Melangyna, but less so than that of the two small Papuan and Australian subgenera of the latter genus. These, however, have terminalia very little different in general structure from those of Melangyna s. str. and can be reasonably considered congeneric with them. Exallandra may be separated from Sphaerophoria by the much smaller genitalia and by the Syrphus-type abdominal colour pattern (Vockeroth 1969).
Adapted from Vockeroth (1969).
Head: Eye bare. Face yellow with broad well-defined black vitta on its entire length; face slightly protuberant, the tubercle abrupt but small.
Thorax: Scutum black, brownish-pollinose medially and laterally, shining sublaterally; postpronotum, and usually a triangular area immediately behind it, bright yellow, the yellow mark usually not extending to suture. Scutellum dull yellow, at least lateral margin black, sometimes entire margin plus a discal spot black. Pleura black, subshining, with bright yellow markings of very varied extent. Subscutellar fringe sparse, absent from about median third of scutellum. Dorsal katepisternal pile patch extending below middle of katepisternum but broadly separated throughout from the greatly restricted ventral patch. Metasternum bare or haired. Posteromedian apical angle of metacoxa without tuft of pile.
Abdomen slender, tapering almost uniformly from base in male, elongate oval in female, unmargined. Terga 2 to 5 each with a pair of slender oblique dull yellow maculae, those of terga 3 and 4 sometimes confluent medially, those of 2 and 5 sometimes absent. Sterna shining black, in female posterior corners of 5 and all of 6 reddish.
Male genitalia: Surstylus articulated along posterior part of ventral margin of tergite 9, sub cylindrical basally, greatly expanded and slightly compressed apically, with broad rounded apical emargination giving it a weakly bifurcate appearance; outer surface with sparse scattered setae dorsally and apically; inner surface on apical fourth with short stout black setulae which become shorter and denser near ventral apex. Sternite 9 dorsally extending far caudad, articulating with a very short surstylar apodeme, in ventral view very broad, with broad and deep emargination bearing a pair of short broad triangular submedian processes. Superior lobe very large, sub quadrangular, strongly compressed, posteroventral margin with slight incurved flange bearing a few rather long setae, posterodorsal angle with long, slender, depressed, slightly curved, finger-like process. Aedeagal base in the form of a broad shallow trough; each lateral margin produced caudad as a compressed, tapering, slightly downcurved process with extreme apex turned sharply mediad; ventral margin produced ventrad and forward as a pair of strongly depressed, rather slender, apically truncate processes; dorsal margin directed sharply forward. Distal portion of aedeagus articulated far ventrad (at base of ventral processes), strongly compressed, sub quadrate in profile, the dorsal portion weakly sclerotized, the remainder membranous and extremely delicate.
GenBank accession number for this species are: protein-coding COI gene (EU241742), rRNA 28S gene (EU241790) and 18S gene (EU241843).
Body length: 5.2 to 7.2 mm (Vockeroth 1969).
Mengual et al. (2008a) studied the phylogenetic relationships of the subgenera of Allograpta and included Exallandra and several species of Sphaerophoria. Exallandra cinctifacies was recovered as sister group of Sphaerophoria loewii, embedded in the Allograpta + Spherophoria clade. This position suggest that Exallandra can be synonym of Sphaerophoria.
Species known from Tanzania, Kenya, Liberia, South Africa and Congo.