Tachydromia pandellei ( Séguy, 1941 )

Gonçalves, Ana Rita, Grootaert, Patrick, Andrade, Rui, Paulo, Octávio S. & Mengual, Ximo, 2021, Revision of the morphology, phylogenetic relationships, behaviour and diversity of the Iberian and Italian ant-like Tachydromia Meigen, 1803 (Diptera: Hybotidae), European Journal of Taxonomy 732, pp. 1-56 : 30-33

Tachydromia pandellei ( Séguy, 1941)

Figs 1 , 11 , 16 G–H, 18 I–J, 19B, 21 A, C

Ariasella pandellei Séguy, 1941: 4 .

Tachydromia pandellei Shamshev & Grootaert 2018: 425 (comb. nov.).

Diagnosis

Overall shiny black with distinct yellow parts. Wing dimorphic: male stenopterous; wing with cordiform (French populations) or lobed apex (Spanish populations); stalk-like portion yellow to light brown; lobed apex with basal half hyaline, distal half black; female stenopterous, stalk-like portion yellowish with minute lobed apex pale brown. Antennae yellow with brownish postpedicel; palpi yellow; proboscis black; postpedicel roundish, approximately as long as pedicel. Legs overall yellow with brownish hind femora and tibiae, tarsomeres yellow and black. Abdomen black, tergites and sternites overall covered with grey microtrichia and setae.

Type material examined

Lectotype (here designated in order to fix the identity of the species) FRANCE • 1 ♂; Hautes-Pyrénées, Arrens-Marsous ; 28 Jun. 1879; L. Pandellé leg.; MHNP-1256 .

Paralectotypes FRANCE • 2 ♂♂, 2 ♀♀; Hautes-Pyrénées, Arrens-Marsous ; 28 Jun. 1879; L. Pandellé leg.; MHNP- 1256 .

Additional material examined

FRANCE • 2 ♂♂, 1 ♀ (all male terminalia studied, RBINS); Hautes-Pyrénées, Arrens-Marsous ; 42°57′20.3″ N, 0°12′52.1″ W; 18 Jun. 2017; A.R. Gonçalves and E. Marabuto leg. • 2 ♂♂, 1 ♀; Hautes-Pyrénées, Arrens-Marsous, Arrens , Route d’Aste; 42°56′14.9″ N, 0°13′45.9″ W; 18 Jun. 2017; A.R. Gonçalves and E. Marabuto leg. • 3 ♂♂, 6 ♀♀; Hautes-Pyrénées, Barèges , Touët et Labach; 42°54′08.1″ N, 0°06′04.0″ E; 19 Jun. 2017; A.R. Gonçalves and E. Marabuto leg. • 1 ♀; Hautes-Pyrénées, Campan ; 42º 55′ 31″ N, 0º11′49″ E; 20 Jun. 2017; E. Marabuto leg.

SPAIN • 5 ♀♀; Burgos, Villasur de Herreros ; 42º18′26.4″ N, 3º19′59.1″ W; 15 May 2014; A.R. Gonçalves and R. Andrade leg.; RBINS • 4 ♂♂, 4 ♀♀; Burgos, Pancorbo ; 42º38′42.4″ N, 3º06′17.1″ W; 11 May 2015; A.R. Gonçalves and R. Andrade leg. • 1 ♂, 5 ♀♀; same collection data as for preceding; ZFMK • 2 ♂♂, 6 ♀♀; Basque Country, Araba / Álava ; 42°59′02.6″ N, 2°49′59.4″ W; 17 Jun. 2017; A.R. Gonçalves leg.

Redescription

Similar to Tachydromia cantabrica sp. nov. except for the following:

Male

MEASUREMENTS. Body length: 2.4–2.8 mm (n = 5). Wing length: 0.9–1.1 mm (n = 5).

HEAD. Ocellar tubercle glabrous. Lateroclinate ocellars 2 times as long as postpedicel. Proclinate verticals 1.5 times as long as postpedicel, numerous very long setae on occiput.

ANTENNA. Scape and pedicel yellow, postpedicel brown. Postpedicel oval, 2 times as long as wide and slightly longer than pedicel; stylus slightly more than 3 times as long as scape, pedicel and postpedicel combined.

PALPUS. Brown in ground colour.

THORAX. Poorly differentiated sclerites, with slightly distinguishable postpronotal lobe, notopleuron, episternum, mesopleuron, pteropleuron, sternopleuron and hypopleuron. Postpronotal lobe very small, mesonotum somewhat humped, scutellum well defined but very short, postscutellum longer and metanotum well developed. Prosternum and episternum densely covered by grey microtrichia. Postpronotal lobe bearing 12 setae laterally, notopleuron with 1 strong, prominent, very long seta, plus 3 smaller ones; 3 setae near base of wing, prescutellum bearing 4 setae, inner setae longer.

WING. Lobed apex cordiform. Stalk-like portion rigid, yellow except for brown basal portion; lobed apex with basal half hyaline (appearing silver under certain light conditions), distal half black ( Fig. 21A ).

LEGS. Overall yellow, except for following brown to black portions: posterodorsal surface of coxae, apical ¼ dorsal surface, posterior and anterior surfaces of hind femur, most of hind tibia, tarsomere 5 of fore and mid-legs, distal apex of tarsomeres 1 and 2, distal ½ of tarsomere 3, distal ¾ of tarsomeres 4 and 5. Mid tibia anteroventral apical spur produced into distinct and long apical elongation ( Fig. 19B ), longer than diameter of tibia at apex; mostly glabrous ventrally but dorsally covered by microtrichia, with a few distinct setae and, on basal half margin, 3 short, stout, curved setae. Elongation mostly glabrous, with a few setae arising marginally and apically.

TERMINALIA ( Fig. 11 ). Right epandrial lamella with long, erect setae mostly on apical half. Right surstylus bifurcated into short projection and very long and slender projection; mostly glabrous but with long, curved lateral setae and 2 denticle-like setae at distal margin of longer projection; short projection with similar setae at distal margin. Right cercus slightly longer than left, both enclosed in epandrial lamellae. Left epandrial lamella as long as left cercus. Left surstylus subcylindrical, narrowing proximately, 4 times as long as wide, as long as right cercus, with setae on lateral margins and apical ½.

Female

Similar to male, except for following features: stenopterous (length of wing (n = 2): 0.7–0.8 mm), with very minute lobed apex, stalk-like portion yellowish with lobe light brown, covered by grey microtrichia ( Fig. 21C ); legs covered with regular rows of setae, with distinct circle of setae on fore femur and anteroapical setae on coxae, but no other distinctive hairs or setae; spur on mid tibia absent; cercus pale brown with grey microtrichia and setae.

Variability

There is a variability in the shape of the wing lobe in males between the populations sampled in the French Pyrenees compared with those from Spain. In the former, the lobed apex is distinctively large and cordiform, while in the latter the lobed apex is comparatively smaller and oval.

Distribution

Spain and France. It is known from the French Pyrenees and a few localities in the northern Spanish province of Burgos and the Basque Country.

Figures

Fig. 1. Currently known distribution of the Iberian ant-like Tachydromia Meigen, 1803. Each dot represents a presence point, with each colour corresponding to a different species. When two species co-occur in the same area, their presence is represented by a smaller dot on top of a dot of regular dimension, each of those with the colour corresponding to the co-occurring species. The dots surrounded by a black circle with a vertical line represent localities previously known.

Fig. 11.Terminaliaof thetopotypeofTachydromia pandellei(Séguy, 1941)from France, Hautes-Pyrénées, Arrens-Marsous, lectotype (RBINS). A. Right surstylus and right epandrial lamella. B. Epandrium with cerci. C. Left epandrial lamella and left surstylus. D. Right surstylus. Scale bar: 0.1 mm.

Fig. 16. Habitus of live specimens of the Iberian ant-like Tachydromia Meigen, 1803 and the Italian flightless Tachydromia. Males are pictured in the left column, females in the right.A–B. T. iberica (Arias, 1919). C–D. T. semiaptera (Gil Collado, 1923). E–F. T. pieltaini (Gil Collado, 1936). G–H. T. pandellei (Séguy, 1941). I–J. T. apterygon Plant & Deeming, 2006 (Italy).

Fig. 18. Mounted specimens of the Iberian ant-like Tachydromia Meigen, 1803. Males are pictured in the left column, females in the right. A–B. T. cantabrica Gonçalves, Grootaert & Andrade sp. nov. C–D. T. iberica (Arias, 1919). E–F. T. semiaptera (Gil Collado, 1923). G–H. T. pieltaini (Gil Collado, 1936). I–J. T. pandellei (Séguy, 1941). Scale bars: 1 mm.

Fig. 21. Drawings of the tip of stenopterous wings and images obtained by scanning electron microscope (SEM) of the micropterous wings. Males are pictured in the left column, females in the right. A, C. T. pandellei (Séguy, 1941). B–C. T. pieltaini (Gil Collado, 1936). D–E. T. semiaptera (Gil Collado, 1923). F–G. T. stenoptera Gonçalves, Grootaert & Andrade sp. nov. Scale bars: A–D, F = 50 µm; E, G = 10 µm.

Fig. 19. Images obtained by scanning electron microscopy of the spur-like structures present on the apical portion of the male mid tibia. A. T. lusitanica (Grootaert, Shamshev & Andrade, 2009). B. T. pandellei (Séguy, 1941). C. T. pieltaini (Gil Collado, 1936). D. T. ebejeri Gonçalves, Grootaert & Andrade sp. nov. E–F. T. semiaptera (Gil Collado, 1923). G. T. stenoptera Gonçalves, Grootaert & Andrade sp. nov. H. T. cantabrica Gonçalves, Grootaert & Andrade sp. nov. I. T. nigrohirta Gonçalves, Grootaert & Andrade sp. nov. J. T. apterygon Plant & Deeming, 2006. Scale bars: 10 µm.