Allotrichoma tskarishdidae Stuke, 2022

Stuke, J. H., 2022, Faunistic and taxonomic remarks on European Allotrichoma Becker, 1896 (Diptera: Ephydridae) with the description of a new species from Georgia, Russian Entomological Journal 31 (3), pp. 297-311 : 304-306

Allotrichoma tskarishdidae Stuke , sp.n.

Figs 12 , 24.

HOLOTYPE. Male: (1) “ Georgia, Mariini Canal / 3.4 km N Jandari / (41.473°N 45.167°E) / 2.07.2019, Stuke leg. / 2473 [cross written]”; (2) “ Holotypus / Allotrichoma tskarishdidae / sp.n. ♂ / Stuke det. 2021”. The specimen is pinned using a minuten and is in excellent condition. The abdomen is dissected, macerated and stored in a glycerine microvial pinned underneath the specimen. The holotype will be preserved in the collection of the Museum für Naturkunde – Leibniz Institute for Evolution and Biodiversity Science, Berlin, Germany ( ZMB).

PARATYPES: GEORGIA: 1♂, 30.vi.2019, Debeda River N Kirach-Mughanlo [41.340°N 45.051°E] ; 1♂, 30.vi.2019, Debeda River W Didi Mughanlo [41.389°N 44,943°E] ; 1♂, 30.vi.2019, Kura River 1.9 km ESE Ilmazo [41.418°N 45.042°E] .

DESCRIPTION HOLOTYPE (♂). Length about 1.4 mm. Wing length = 1.2 mm. Head height = 0.4 mm.

Head black. Gena-eye-ratio (in lateral view genal height measured at the maximum eye height: eye height) = 0.2. Antenna black, slightly silver dusted. Arista black, with 4 long branches. Eye red brown, all ommatidia about same size, no ommatrichia recognized. Eye height-length-ratio (in lateral view maximum eye height: maximum eye length) = 1.3. Ocelli forming an almost isosceles triangle. Frons silver grey to brown dusted with fronto-orbital plate and lunule densely silver dusted. Frontal triangle indistinct, large, reaching to ptilinal suture. Face not protruding, silver dusted. Facial ratio (distance between the oral margin and the dorsum of the ptilinal fissure: narrowest distance between the compound eyes across the face) = 1.0. Clypeus black, short, slightly silver grey dusted. Gena silver dusted Occiput silver grey dusted. Palpus black. Proboscis inconspicuous. Chaetotaxy: large ocellar seta inserted lateral to anterior ocellus; no setulae between ocelli; 1 large proclinate postocellar seta; 1 outer and 1 inner vertical seta of about the same size; no paravertical seta; regularly arranged line of postocular setae; 1 proclinate and 1 reclinate fronto-orbital setae; no frontal setulae; 2 large inclinate facial setae and 2 minute facial setulae; 1 prominent genal seta and 3–4 genal setulae.

Thorax covered with brown to silver grey dusting. Scutum with lines of short black setulae. Scutum and scutellum grey dusted; scutum with a central stripe and 2 sublateral stripes of distinct brown dusting. Anepisternum and katepisternum with scattered setulae. Pleura silver grey dusted with a brown spot dorsally at the anepisternum and dorsally at the notopleuron. Chaetotaxy: 2–4 lines of acrostichal setae; 0+1 dorsocentral setae; 1 prescutellar seta; 1 presutural supra alar seta; 1 postpronotal seta; 2 notopleural seta, posterior inserted above level of anterior; 1 postalar seta; 1 large apical, 1 large lateral, 1 small lateral and 2 small central scutellar setae; 1 posterodorsal katepisternal seta; 2 setae at posterior margin of anepisternum. Wing hyaline, completely covered with microtrichia. Veins light brown. Costa without seta between subcostal break and R 4+5. Alula small, with long brown setulae at its hind margin. Costal index I (straight line distance between the apices of R 1 and R 2+3 [section 2 of Costa]: straight line distance between the apices of R 2+3 and R 4+5 [section 3 of Costa]) = 2.6. Costal index II (straight line distance between the apices of R 4+5 and R 2+3 [section 3 of Costa]: straight line distance between the apices of Media and R 4+5 [section 4 of Costa]) = 2.5. R 4+5 vein-ratio (straight line distance along vein R 4+5 between crossvein r-m and branch of R 4+5 and R 2+3 [section 1 of R 4+5]: distance apicad of r-m [section 2 of R 4+5]) = 0.1. M vein-ratio (straight line distance along vein M between crossveins dm-cu and r-m [section 1 of M]: distance apicad of dm-cu [section 2 of M]) = 0.4. Costa reaching apex of media. Radial vein R 4+5 almost straight. Haltere whitish with light brown base. Legs black to brown with bases and apices of tibiae yellow brown and three basal tarsomeres yellow. Legs silver grey dusted with the exception of hind side of shining hind femur and hind tibia. Legs covered with short black setulae. Hind metatarsus ventrally with dense golden setulae.Fore femur posterodorsally with 5–6 black setae; middle femur anterodorsally with 4 setae. Metatarsus IItibia II-ratio (length metatarsus 2: length tibia 2) = 0.4.

Abdomen black. Tergites grey dusted and covered with black setulae. Tergite III-IV-ratio (length tergite 3 medially: length tergite 4 medially) = 0.8. Tergite IV-V-ratio (length tergite 4 medially: length tergite 5 medially) = 0.5. Sternites 2–5 each with 2–5 black setulae. No process of sternite 5 (“medial process at 5th sternal flap” sensu Mathis and Zatwarnicki 2012) but with a pair of triangular extensions and base of sternite 5 with long posterior directed setae ( Fig. 24). Cercus-epandrium-surstylus-complex as shown in Fig. 12 . Epandrium with 2 strong setae. Cercus with 2 large apical inwards curved setae and 3 smaller, subapical, ventral, upwards curved setae. Surstylus completely fused with epandrium and not distinct. Its position might be marked by a row of ventrally directed setulae ( Fig. 12 ). Postgonite long, straight, with broad base, with two lateral directed small setulae and no obvious seta at its base. Phallus apodeme triangular with the muscle attachment slightly backwards directed. Phallus elongated and without any obvious characters.

Female: Females cannot currently be identified.

DIAGNOSIS: Allotrichoma tskarishdidae sp.n. belongs to a group of Allotrichoma species that is easily recognised by this set of characters: (i) face only shallowly convex and not protruding nor with a tubercle; (ii) sternite 5 without distinct process ( Fig. 24); (iii) surstylus, cercus and epandrium fused. Four Allotrichoma species are known from the Palaearctic and from the Arabian Peninsula to belong to this quadripectinatum -species group: A. choanum Mathis et Zatwarnicki, 2017 (United Arabian Emirates), A. hatta Mathis et Zatwarnicki, 2017 (United Arabian Emirates), tuareg Giordani Soika, 1956 ( Algeria, Morocco) and A. quadripectinatum ( Becker, 1903) [ Fig. 29 ]. This quadripectinatum species group shares impor-

Remarks on European Allotrichoma 305 tant characters with the dyna species-group as defined by Mathis and Zatwarnicki [2012]. With the set of characters given in their cladogram [ Mathis, Zatwarnicki, 2012: 10, Figure 2 ] an assignment to one of their species-groups is not possible. To distinguish the species of the quadripectinatum species group the shape and setulation of the terminalia has to be taken into account. Allotrichoma tskarishdidae sp.n. is distinguished from all other species by (iv) the presence of 2 dominant, moderately long and (in dorsal view) medially curved setae at the tip of the cercus and additional upcurved setae ventrally to these ( Fig. 12 ), (v) the lack of obvious setae at the postgonite and (vi) a finger like tip of cercus ( Fig. 12 ).

14 15 13 16 18 17 21 19 22 20 23 24

ETYMOLOGY: Allotrichoma tskarishdidae sp.n. is dedicated to Tskarishdida (-). In Georgian myths Tskarishdida is a half-fish and half-woman deity of rivers and lakes.

DISTRIBUTION: The records of this species are confined to a small area of the Kura river and its tributary. All locations are situated in Georgia close to the border with Azerbaijan ( Fig. 32 ).

ECOLOGY: All specimens were collected at the sparsely vegetated shores of rivers.

Figures

Figs 9–12. Epandrium, cercus, surstylus of European Allotrichoma, dorsal view (above) and lateral view (below): 9 — sicanum Canzoneri, 1980; 10 — strandi Duda, 1942; 11 — trispinum Becker, 1896; 12 — tskarishdidae sp.n. Рис. 1—12. Эпандрий, церки и сурстили европейских видов Allotrichoma, сверху (верхний рис.) и сбоку(ниЖний рис.): 9 — sicanum Canzoneri, 1980; 10 — strandi Duda, 1942; 11 — trispinum Becker, 1896; 12 — tskarishdidae sp.n.

Fig. 29. Records of Allotrichoma quadripectinatum [Becker, 1903] (based on the data presented in this paper and data from Becker [1903], Beschovski, Zatwarnicki [2002], El-Hawagry et al. [2018], Giordani Soika [1956, as A. bellicosum], Stuke [2012], Vite [1991, as A. bellicosum]). Рис. 29. Распространение Allotrichoma quadripectinatum [Becker, 1903] (по данным представленной статьи и работ Becker [1903], Beschovski, Zatwarnicki [2002], El-Hawagry et al. [2018], Giordani Soika [1956, как A. bellicosum], Stuke [2012], Vite [1991, как A. bellicosum]).

Figs 1–4. Epandrium, cercus, surstylus of European Allotrichoma, dorsal view (above) and lateral view (below): 1 — bezzii Becker, 1896; 2 — bifidum Papp, 1974; 3 — filiforme Becker, 1896; 4 — laterale (Loew, 1860); ce — cercus; ep — epandrium; pce — protruding part of cercus; su — surstylus. Рис. 1—12. Эпандрий, церки и сурстили европейских видов Allotrichoma, сверху (верхний рис.) и сбоку (ниЖний рис.): 1 — bezzii Becker, 1896; 2 — bifidum Papp, 1974; 3 — filiforme Becker, 1896; 4 — laterale (Loew, 1860); ce — церк; ep — Эпандрий; pce — выступаюЩаЯ часть церка; su — сурстиль.

Fig. 32. Records of Allotrichoma tskarishdidae sp.n. Рис. 32. Распространение Allotrichoma tskarishdidae sp.n.