Trichocera (Saltrichocera) chuluuta, Petrašiūnas, Andrius & Podėnas, Sigitas, 2011

Petrašiūnas, Andrius & Podėnas, Sigitas, 2011, Notes on winter flies Trichoceridae (Diptera) of Mongolia with description of new species, Zootaxa 3031, pp. 61-68 : 63-66

Trichocera (Saltrichocera) chuluuta sp. nov.

( Figs. 1–9 )

Etymology. The name of the species refers to the district of Mongolia – Chuluut Soum, where the holotype and several paratypes were collected.

Material examined. Holotype Male, MONGOLIA: Arkhangay Aimag, Chuluut Soum, Khurmen/Davaat Gol (river), 15 km SSE of Chuluut/Jargalant, N47.42580 E100.30130, elevation 2104 m, 15 July 2004, ultraviolet trap, SRP 04071503, ( Fig. 10 ). The holotype belongs to the collection of the Mongolian Academy of Sciences, Ulaanbaatar; it is on long-term loan to the Academy of Natural Sciences of Philadelphia.

Paratypes: MONGOLIA: 1 male, Bayan Olgiy Aimag, Ulaanhus Soum, Ulastoi Gol, 2 km E of Khokh Military Outpost, N 49.31857 E 0 88.36612, elevation 2392 m, 8 July 2008, coll. S. Podėnas, MAIS 0 8070802, (MZVU-T0053, specimen and genitalia are stored in glycerin in separate microvials that are pinned, with labels pined below the vials); 1 male, Arkhangay Aimag, Ikhtamir Soum, NW braid of Khoit Tamir Gol ~ 25 km SW of Ikhtamir, N47.50523 E100.93208, elevation 1728 m, 14 July 2004, ultraviolet trap, SRP 04071402 (labeled as paratype 1); 1 male (labeled as paratype 2), 1 female, Arkhangay Aimag, Chuluut Soum, Khurmen/Davaat Gol 15 km SSE of Chuluut/Jargalant, N47.42580 E100.30130, elevation 2104 m, 15 July 2004, ultraviolet trap, SRP 04071503 (female MZVU-T0052, specimen and genitalia are stored in glycerin in separate microvials that are pinned, with labels pined below the vials).

Diagnosis. Medium-sized species. Body coloration brown. Metepisternum with one or two setae. Male terminalia with bridge high and narrow, bilobous at the end. Gonostylus with large mesal process at 1/2 of its length. Ninth sternite with wide desclerotized area at posterior margin. Female with slender, weakly bent ovipositor, 1.1 times longer than sternite VIII; setulose area narrow, clearly delimited, tergites 9 and 10 fused at the dorsal side ( Fig. 7 ). Body length 7–8 mm, wing length ~ 8 mm.

Description. Head. Antenna ( Fig. 1 ) similar in male and female, three times as long as the length of the head, reaching the base of the abdomen if bent backward. First flagellomere slightly broader than following ones; it is 1.5–1.6 times as long as second flagellomere and 2–2.3 times as long as pedicel. All consecutive flagellomeres starting from third are slightly longer and thinner than the previous one. Length of verticils 2.5 to 3 times exceeds that of pubescence.

Thorax and pleura uniformly brown. Metepisternum of holotype and all paratypes with two small setae, except paratype 1 that has only one. Wing tinged with brownish, veins brown. Sc ventrally covered with setae all along its length, but only 5 (in males) and 10 (in female) setae are situated dorsally. R2+3+4 longer than R2+ 3 in holotype, but R2+3+4 shorter or subequal to R2+ 3 in all paratypes. Discal cell narrow ( Fig. 2 ), 2.4–2.5 times as long as wide. Length ratio of basal, median and distal sections of M1+2 is about 1: 1.6: 2. A2 dorsally covered with macrotrichia up to the bend, and is situated close and parallel to the wing margin. Legs uniformly brown. Tarsal claw of male ( Fig. 3 ) uniformly arched and exceeds half length of last tarsal segment.

Abdomen greyish brown. Male terminalia ( Figs. 4, 5, 6 ): ventrobasal lobe of gonocoxite wide at base and narrowing towards the tip, bridge high, bilobous at the end, beak-like in lateral view. Gonocoxite about twice as wide as gonostylus and forms a distinct lump-like structure on its distal dorsal part that is covered by dense setae ( Fig. 5 ). Gonostylus with apical lobe directed meso-ventrally and covered with dense setae. It has large mesal process at middle. Sternite 9 with wide desclerotized area at posterior margin. Complex of aedeagus ( Fig. 6 ) narrow in basal part. Parameres of moderate length, parallel to each other, except just slightly diverging tips. Lateral apodemes rounded. Basal apodemes uniformly broad, directed to each other ventrally. Aedeagal apodeme finger-shaped, comparatively short, about one-seventh length of aedeagus.

Female terminalia ( Figs. 7, 8, 9 ): ovipositor slightly (~ 1.1 times) longer than sternite VIII, slender, almost straight. Setulose area narrow, clearly delimited, covering about 0.4 length of ovipositor ( Fig. 7 ). Genital plate with slight medial incision of a blunt angle, lateral edges of the genital plate near the fork are clearly bent down, forming a distinct dark ridge; fork of the vaginal apodeme semicircular, apodeme itself slightly wider at the proximal half, narrowing towards apex ( Fig. 8 ). Supragenital plate with acute tip and two bristles. Length of sclerotized part of spermathecal duct half as long as diameter of spermatheca ( Fig. 9 ).

Remarks. The correspondence of males to female was established by general body coloration, shape of d-cell and similar form of antennae. Moreover, two males and one female were caught at the same time in the same location (SRP 04071503).

The new species could be distinguished from all Trichocera by peculiarities of structure of male terminalia. Mesal process of gonostylus resembles that of T. colei Alexander ( Krzemińska, 2001: fig. 1) T. sakaguchii Alexan- der ( Krzemińska, 2001: figs. 11–15), T. tetonensis Alexander ( Krzemińska, 2001: figs. 16–18) and T. ticina Starý and Podėnas (Starý & Podėnas, 1995 : figs. 1–3) by being positioned at the middle of the length of the gonostylus. T. (S.) chuluuta sp. nov. yet has mesal process directed towards the basal part of gonostylus compared to that directed towards the distal end of gonostylus in T. sakaguchii or T. ticina while process of T.tetonensis is thicker. The general form of gonostylus of T. ticina is also rather similar to that of new species, but the apical lobe of T. (S.) chuluuta sp. nov. is directed meso-ventrally compared to more dorsal direction in T. ticina . The three above mentioned species differ externally from the newly described species in the form of gonocoxal bridge and ninth sternite, which is complete, without desclerotized area.

The newly described species has a gonocoxal bridge similar in lateral view to that of T. kotejai Krzemińska (Krzemińska, 1992 : figs. 4–8) and T. salmani Alexander ( Pratt & Pratt, 1984: fig. 17; Byers & May, 1978: figs. 1– 3), but differs by the form of gonostylus, which has long and thin outgrowth both in T. kotejai and T. salmani compared to short mesal process in T. chuluuta sp. nov.; sternite 9 has a rather deep pit in the center in T. kotejai or is complete in T. salmani , but not desclerotized as in the newly described species.

The shape of the ovipositor of T. (S.) chuluuta sp. nov. resembles that of T. kotejai ( Krzemińska 1992: figs. 9– 10), T. borealis Lackschewitz ( Dahl & Krzemińska, 2008: fig. 2), T. brevis Krzemińska (Krzemińska, 2002b : figs. 1–4) and T. recondita Starý (Starý, 2000 : figs. 11–12), but the new species could be separated from them by the different form of the fork of the vaginal apodeme and the supragenital plate as well as the different form of antennal flagellomeres. Supragenital plate has four bristles in T. kotejai and T. brevis compared to only two in T. chuluuta sp. nov.; distal lateral parts of the fork of the vaginal apodeme are very short in T. borealis compared to the ones in the newly described species, although the fork of apodeme in T. chuluuta sp. nov is robust and forming almost a circle like that in T. brevis . The genital plate in T. recondita is almost quadrangular and the fork of the vaginal apodeme is wide compared to more trapezoid plate and narrow fork, not clearly different in width from the rest of the vaginal apodeme in T. chuluuta sp. nov.

The newly described species doesn’t fully fit the original description of the subgenus by having gonostyles with outgrowths that are considered as distinguishing feature for subgenus Metatrichocera . On the other hand, the aedeagal complex is typical, so we assign T. chuluuta sp. nov. to the subgenus Saltrichocera .

Figures

FIGURE 10. Type locality of Trichocera (Saltrichocera) chuluuta sp. nov.

FIGURES 1 – 9. Trichocera (Saltrichocera) chuluuta sp. nov. 1) male antenna, proximal segments (holotype); 2) wing; 3) male tarsal claw (MZVU-T 0053); 4) general view of male terminalia, lateral view; 5) general view of male terminalia, ventral view; 6) male terminalia, aedeagal complex, lateral view (MZVU-T 0053); 7) ovipositor, lateral view; 8) genital plate; 9) spermatheca with sclerotized part of spermathecal duct (7 – 9 paratype, MZVU-T 0052). Bars = 0.25 mm. Abbreviations: br, bridge; mp, mesal process; gncx, gonocoxite; gnst, gonostylus; ba, basal apodeme; la, lateral apodeme, p, paremere; va, vaginal apodeme; gp, genital plate; sg, supragenital plate; VIIIs, sternite VIII.