Roeseliana fedtschenkoi ( Saussure, 1874 )

Massa, Bruno, Tagliavia, Marcello, Buzzetti, Filippo Maria, Fontana, Paolo, Carotti, Giovanni, Bardiani, Marco, Leandri, Fausto, Scherini, Roberto & Verde, Gabriella Lo, 2023, A taxonomic revision of the Palaearctic genus Roeseliana (Orthoptera: Tettigoniidae: Tettigoniinae: Platycleidini): a case of ongoing Mediterranean speciation, Zootaxa 5270 (3), pp. 351-400 : 362-363

Roeseliana fedtschenkoi ( Saussure, 1874)

Figs. 6e , 10

Saussure, 1874. Mém. Soc. Sci. nat. Antrop. Ethnogr. Univ. Moscou, 11: 45 ( Decticus (Platycleis) fedtschenkoi ); type locality and depository: Uzbekistan, Maracanclam et prope Bairakum ad flumen Jaxartem (Samarkand, Syr Daria) (syntypus, ZMUM) .

Found near Samarkand on June 8, 1869 (larva) and May 17, 1871 in Bayrakum.

Brown-green or yellowish-green color. The head is wide, smooth; the top of vertex is broad and blunt, on its sides above the eyes there is a horizontal brown stripe, separated or bordered by a yellowish line, extending from the eyes; vertex is decorated with three pale longitudinal lines, from which the lateral lines follow the edges of the brown stripes. The antennae are dark, green at the base. Mesothorax width the same as its length; the upper surface of mesothorax is wide, flat, slightly convex at the front end, slightly concave in the middle; the middle lobe is very weakly expressed, the lateral lobes are blunt; the rear edge is cut off, slightly turned upwards; the folded edge comes onto the lateral lobes of pronotum; the latter is bordered by a whitish stripe and decorated with irregular brown spots (or the area along the lobes and along the edges of the lobes is brown); rear part of side lobes of pronotum is blunt cut.

The colour is green-brown or yellow-green. The head is broad and smooth; the apex of the head is broad and obtuse; on the sides, above the eyes, there is a horizontal brown stripe which divides a yellowish stripe or surrounds it, there are three pale lines running along the brown stripe, of these, the lateral ones reach the ends of the brown stripe. Width of the front part of the thorax equal to the length; the upper surface is broad and flat, slightly convex in the fore margin and slightly concave in the middle; the lobe of the middle is not very pronounced, the lateral lobes are a little obtuse, the hind edge is truncated, slightly raised; this raised edge joins with the lateral keels; in the anterior part of the pronotum there is a pale line with irregular brown flecks; the posterior edge of the lateral keels is cut obtusely at the point where they go towards the posterior side of the anterior part of the pronotum.

Tegmina red-yellow, rounded at the apex, cover the entire abdomen except its three posterior segments; the veins of the elytra are brown, with the exception of a green “shoulder” vein, which is arcuately curved and gives five brown branches near its middle. The tympanum is poorly developed, the stridulatory file is poorly developed and is covered in the anterior part by the pronotum; the mirror is not closed, it has only the outer vein. The wings are rudimentary.

The legs and body are concolourous. The hind femora are adorned with a longitudinal brown stripe. The ventral side of abdomen is pale. The supra-anal plate is incised with an oblong impression in the form of A on its surface; this depression is narrow, rounded-blunt at the apex, surrounded by hairs, has prominent sharp edges; the supra-anal plate is deeply incised at the apex. This notch has almost the same shape as the depression on the surface of the plate; the corners of the edges of the notch continue into triangular tongue-like spines. The cerci are long, somewhat protruding from the stylet-like processes of the subgenital plate; on their apical third, they are each armed with one sausage-like process, which apex is black. The subgenital plate is large, with an impression at its base, equipped with three strongly developed ribs, rounded at the free edge and incised in the form of V. The cerci are long, a little protruding from the plate cavity, in the distal third there is a black spine.

Remarks. Saussure (1874) wrote that tegmina cover the entire abdomen, excluding three posterior segments, tegmina of the syntypes cover only one third of abdomen ( Fig. 10 ). In addition, Saussure (1874) compared the species with Platycleis brevipennis (Charpentier, 1825) (currently synonym of R. roeselii ), pointing out that R. fedtschenkoi is larger, has shorter tegmina, supra-anal plate of different shape and less developed tympanum. Later, Stshelkanovtzev (1907) recorded another male from Sossyur ( Turkmenistan) and described the female from Lake Balkhash ( Turkmenistan), pointing out that it was similar to R. roeselii , with tegmina apex less obtuse, shorter ovipositor, bigger size, but the subgenital plate very similar to that of R. roeselii .

Thanks to the kindness of A. Gorochov, O. Korsunovskaya, V. Savitsky, and A. Ozerov we were able to examine the photo of the supra-anal plate of the syntype ( Figs. 6e , 10 ), finding that it is very similar to that of R. pylnovi , including the male titillators, apically hooked, but different from R. roeselii , whose titillators are differently shaped.

All authors agree with the validity of this taxon, with the exception of Heller (1988), who has considered it synonymous with R. roeselii (see above, R. roeselii ). Tarbinsky (1932) considered R. pylnovi synonym of R. fedtschenkoi ; indeed, in many museums there are specimens from Caucasian area identified as R. fedtschenkoi . According to Ĝtz (1969), R. fedtschenkoi ( vasilii included), R. pylnovi , R. ambitiosa , R. azami , and R. minor constitute a ‘Rassenkreis’, a ring of neighbouring populations that exhibit a pattern of geographical replacement of one type by another. However, he treated vasilii , pylnovi , ambitiosa , minor and azami as subspecies of fedtschenkoi , without having studied specimens of true R. fedtschenkoi . Stolyarov (2005) followed the same arrangement. More recently, Chobanov & Mihajlova (2010) and Iorgu et al. (2013) treated R. fedtschenkoi as a subspecies of R. roeselii . See R. roeselii , Tables 2 and 4 . The song of R. fedtschenkoi is presently unknown.

Distribution. This species has been described from Uzbekistan, later it was collected in Turkmenistan, and probably it is restricted to the East Asia, while in West Asia and North Europe it is replaced by R. pylnovi and R. roeselii . According to Stolyarov (2005) it should be present also in Azerbaijan, Dashkesan, but specimens from this country could eventually belong to R. pylnovi .

Figures

FIGURE 6. Dorsal view of the male supragenital plate and cerci of four taxa of Roeseliana.

FIGURE 10. Habitus of five taxa of the genus Roeseliana.