Athyroglossa (Athyroglossa) kuraensis, Introduction, 2021

Introduction, Jens-Hermann Stuke, 2021, New European species of Athyroglossa Loew, 1860 (Diptera: Ephydridae) from Finland and the Republic of Georgia, Bonn zoological Bulletin 70 (1), pp. 85-95 : 88-94

Athyroglossa (Athyroglossa) kuraensis spec. nov.

( Figs 2 , 6 , 12 , 18 , 24 )

urn:lsid:zoobank.org:act:30B1D772-4884-464B-B308-86441830440B

Type material

Holotype. GEORGIA: ♂; (1) “ Georgia , Debeda River / n Kirach-Mughanlo / (41,340°N 45,051°E) / 30.06.2019, Stuke leg. / 2459 [cross written]”. – (2) “ Holotypus / Athyroglossa kuraensis ♂ / spec. nov. ♂ / Stuke det. 2020”. [The specimen is pinned using a minuten and is in excellent condition ( Fig. 2 ). The holotype will be pre- served in the collection of the Museum für Naturkunde – Leibniz Institute for Evolution and Biodiversity Science, Berlin, Germany ( ZMB).]

Paratypes. GEORGIA: 4 ♂♂, 1 ♀; 30.vi.2019, Debe- da River E of Kirach-Mughanlo [41,334°N 45,068°E] ; 4 ♂♂, 2 ♀♀; 30.vi.2019, Debeda River N of Khan- ji-Gazlo [41,357°N 45,005°E], leg. Stuke. – 7 ♂♂, 3♀♀; 30.vi.2019, Debeda River n Kirach-Mughanlo [41,340°N 45,051°E], leg. Stuke. – 1 ♀; 30.vi.2019, Kura River 1.6 km E of Ilmazo [41,428°N 45,043°E], leg. Stuke. – 1 ♀; 30.vi.2019, Kura River 2.0 km ESE Ilmazo [41,420°N 45,044°E], leg. Stuke.

Description (holotype, ♂)

Body length about 2.3 mm. Wing length = 1.8 mm. Head height = 0.7 mm.

Head black. Gena-eye-ratio (in lateral view genal height measured at the maximum eye height:eye height) = 0.7. Scape black, pedicel and first flagellomere orange brown. First flagellomere strongly white dusted. Arista black, with 9 dorsal rays, basal rays slightly longer than width of basal aristomere. Eye brown, all ommatidia about same size, with minute ommatrichia. Eye height-length-ratio (in lateral view maximum eye height:max- imum eye length) = 1.5. Ocelli forming an isosceles tri- angle. Frons shining. Frontal triangle indistinct, reaching forward to the ptilinal fissure. Frontal triangle polished, interfrontal vitta otherwise fine longitudinal wrinkled. Facial grooves with indistinct facial carina. Ventral face bulging and stretching ventrally beneath the clypeus. Facial grooves and parafacia strongly silver dusted. Clypeus large, slightly wider than high, shiny, slightly microsculptured. Gena large, polished in upper ⅔ and microsculptured in ventral ⅓. Anteroventral margin and posteroventral margin of gena forming an angle of about 65°. Postcranium subshining. Palpus brown, without se- tae. Proboscis reaching to mouth edge. Chaetotaxy head: 1 ocellar seta; 1 postocellar seta about as long as vertical setae; 1 outer and 1 inner vertical seta; several minute postorbital setae; 1 distinct reclinate fronto-orbital-seta and 2 minute proclinate front-orbital setae; 1 large dorsal and about 8 minute (difficult to see) facial setae; 1 dis- tinct proclinate genal seta.

Thorax black. Scutum finely microsculptured, scutel- lum more roughly microsculptured. Scutum and scute- llum covered with short, brown, scattered setulae that are not arranged in lines. Scutum medially subshining to slightly dusted, laterally shining. Scutellum subshin- ing. Anepisternum with several setulae. Posterior half of anepimeron, meron, katatergite, subscutellum and dorsal half of mediotergite dusted. Other pleurae shining. Chae- totaxy thorax: no acrostichal seta; 0+1 dorsocentral seta; 0 prescutellar seta; 1 intra-alar seta; 0 supra-alar seta; 1 small postpronotal seta; 2 notopleural seta, posterior inserted above level of anterior; 0 postalar seta; 1 sub- apical + 1 lateral scutellar seta, both situated on small tu- bercles; 1 small katepisternal seta; 1 small anepisternal seta. Wing membrane hyaline, indistinctly darker around dm-cu. Veins white but dm-cu, middle part of R 2+3, mid- dle part of R 4+5 and apex of CuA 1 dark brown. Wing com- pletely covered with microtrichia. Alula about twice as wide as long. Dark brown setulae at hind margin of alula about as long as alula.

Costal index I (straight line distance between the api- ces of R 1 and R 2+3 [section 2 of costa]:straight line dis- tance between the apices of R 2+3 and R 4+5 [section 3 of costa]) = 3.0. Costal index II (straight line distance dis- tance between the apices of R 4+5 and R 2+3 [section 3 of costa]:straight line distance between the apices of Me- dia and R 4+5 [section 4 of costa]) = 2.1. 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]:dis- tance apicad of r-m [section 2 of R 4+5]) = 0.2. 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]) = 0.5. Base and stem of halter light brown, knob of halter white. Legs black with apex of fore and hind tibiae yellow and middle tibia yellow. All 3 basal tarsomeres light yellow. Legs partly silver to grey dusted with middle tibia completely dusted. Legs covered with small setulae. Obvious are slightly longer posteroventral setulae on the fore femur. Middle tibia distally with 2 ventral setae. Metatarsus II-tibia II-ratio (length meta- tarsus 2:length tibia 2) = 0.5. Fore femur distally with 5 inconspicuous posteroventral short spines.

Abdomen black. Tergites laterally reflexed under. Terg- ites smooth. Tergite 1 completely dusted. Tergites 2 + 3 broadly dusted in the middle. Tergite 4 broadly dusted in anterior 2/3 of the middle, tergite 5 only with a small central macula. Tergites covered with single brown setu- lae. Tergite III-IV-ratio (length tergite 3 medially:length tergite 4 medially) = 0.8. Tergite IV-V-ratio (length terg- ite 4 medially:length tergite 5 medially) = 2.2.

Description of male postabdomen and sternites based on 3 dissected paratypes: Sternites 3–5 as shown in gated, pointed, dorsally almost straight, and ventrally with a subapical indentation. Pregonite distinct, with an almost circular base and a pointed anterior tip.

Variability. The colouration of mid tibia varies between yellow and light brown. The amount of dusting on scu- tum may be less in older specimens.

Female. Females do not differ from males other than in characters of the postabdomen.

Diagnosis. Athyroglossa kuraensis spec. nov. has a reduced postocellar seta, white halteres, dark brown to black fore and hind tibiae and white basal fore tarsomeres and therewith can be only confused with A. nudiuscula . A. nudiuscula Loew, 1873 is compared with A. kuraensis spec. nov. in the key below. The most obvious diag- nostic character of A. kuraensis spec. nov. is the slightly dusted scutum and scutellum. With the table of the West Palaearctic species of Mathis & Zatwarnicki (1990) A. kuraensis spec. nov. will be identified as non-Euro- pean A. argyrata . Both species share important charac- ters, such as dusting of the scutum and scutellum, white veins at the wing base and antenna that are partly orange. However, A. argyrata has a distinctly microsculptured face below the antennal grooves (polished in A. kuraensis ), light yellow orange hind tibia (brown to black in A. kuraensis ), dorsally shining middle tibia (completely dusted in A. kuraensis spec. nov.) and obviously dusted parafacial and facial ridge (only parafacial partly dusted in A. kuraensis spec. nov.).

Etymology. This species is named after the Kura river. The type material originates from the Kura and its tribu- tary, the Debeda river.

Distribution. Although Ephydridae have been collect- ed all over eastern Georgia and suitable habitats with other Athyroglossa species have been visited regularly, A. kuraensis spec. nov. has only been recorded thus far from a very small area at the border with Azerbaijan ( Fig. 27).

Ecology. All specimens of A. kuraensis spec. nov. were collected by sweeping at shores of the Debeda or Kura rivers or a nearby gravel pit with little or no vegetation. Sympatric species of Athyroglossa recorded at the locations are A. nudiuscula and A. ordinata . However, A. kuraensis spec. nov. was the most numerous species among the collected specimens of Athyroglossa .

Figures

Fig. 2. Habitus of Athyroglossa kuraensis spec. nov., holotype, ♂.

Figs 3–8. ♂; sternites 3–5 (ventral view) of European Athyroglossa. 3. Athyroglossa fennica spec. nov. 4. A. flaviventris (Meigen, 1830). 5. A. glabra (Meigen, 1830). 6. A. kuraensis spec. nov. 7. A. nudiuscula Loew, 1873. 8. A. ordinata Becker, 1896.Abbreviations: S3 = sternite 3; S = sternite 5.

Figs 9–14. Epandrium, surstylus and cercus (dorsal view) of European Athyroglossa. 9. A. fennica spec. nov. 10. A. flaviventris (Meigen, 1830). 11. A. glabra (Meigen, 1830). 12. A. kuraensis spec. nov. 13. A. nudiuscula Loew, 1873. 14. A. ordinata Becker, 1896. Abbreviations: ce: cercus, ep: epandrium, su: surstylus.

Figs 15–20. Epandrium, surstylus, hypandrium and cercus (lateral view) of European Athyroglossa. 15. A. fennica spec. nov. 16. A. flaviventris (Meigen, 1830). 17. A. glabra (Meigen, 1830). 18. A. kuraensis spec. nov. 19. A. nudiuscula Loew, 1873. 20. A. ordinata Becker, 1896. Abbreviations: ce = cercus; ep = epandrium; hyp = hypandrium; hypb = hypandrial bar; phyp = projection of hypandrium; su = surstylus.

Figs 21–26. ♂; Hypandrium (ventral view) of European Athyroglossa. 21. A. fennica spec. nov. 22. A. flaviventris (Meigen, 1830). 23. A. glabra (Meigen, 1830). 24. A. kuraensis spec. nov. 25. A. nudiuscula Loew, 1873. 26. A. ordinata Becker, 1896. Abbreviations: hypb = hypandrial bars; phyp = projection of hypandrium.