Solieria variabilis Gilasian & Ziegler, 2025

Gilasian, Ebrahim & Ziegler, Joachim, 2025, A new species of the genus Solieria Robineau-Desvoidy (Diptera: Tachinidae) from Iran, Journal of Insect Biodiversity and Systematics 11 (1), pp. 227-237 : 229-233

Solieria variabilis Gilasian & Ziegler sp. nov. ( Figs 2, 3, 4A)

https://zoobank.org/ urn:lsid:zoobank.org:act:E5B22DDD-0109-4F18-A200-B85B360969BA

Type material. Holotype ♂ (pinned) “ IRAN: Mazanderan Province / Kandovan (Kuhha-ye Alborz) / north of Tehran / 36°10'20.8''N 051°18'55.8''E / 25.VII.2005 2570 m / legit Joachim Ziegler // 28.851” [white labels]; “ HOLOTYPUS ♂ / Solieria variabilis / Gilasian & Ziegler 2024” [red label]; collected on flowers of Mentha longifolia var. asiatica (Boriss.) Rech.fil. ( Lamiaceae ) [ ZMHB]. Paratypes: 3 ♂♂ (pinned) [coll. nos. 28.850, 28.852 ‒853], same data as holotype [ HMIM, ZMHB]; 1 ♀ [photographed (see Fig. 4A) and pinned, coll. no. 28.835]; same data as holotype except 24.VII.2005 [ ZMHB]; 1 ♂ (pinned) [coll. no. 26.877] Iran, Kohgiluyeh & Boyer-Ahmad Province, Dena Protected Region, northeast of Si Sakht (Kuh-e Dihar), northwest of Yasuj, 30°53'15.4''N 051°30'42.2''E, 08.VII.2004, 3200 m, on flowers of Euphorbia heteradenia Jaub. & Spach ( Euphorbiaceae ), leg. J. Ziegler [ ZMHB]; 3 ♂♂ (pinned) [coll. nos. 26.634‒636] Iran, Chaharmahal & Bakhtiari Province, Guganak, northwest of Shahr-e Kord, 32°33'10.8''N 050°19'54.6''E, 03.VII.2004, 2200 m, on flowers of Euphorbia spec. ( Euphorbiaceae ), leg. J. Ziegler [ HMIM, ZMHB]; 1 ♂ (pinned) Iran, Chaharmahal & Bakhtiari Province, Chelgerd, Guganak, 02.VII.2004, 2200 m, leg. E. Gilasian [ HMIM]; 1 ♂ [coll. no. 26.772] Iran, Chaharmahal & Bakhtiari Province, Sabz Kuh Protected Area (Kuh-e Kalur), southeast of Naghan, south of Shahr-e Kord, Valley, 31°46'22.2''N 050°58'56.9''E, 05.VII.2004, 2550 m, on flowers of Rhabdosciadium aucheri Boiss. ( Apiaceae ), leg. J. Ziegler [ ZMHB]; 2 ♂♂ 2 ♀♀ (glued to a card point) Iran, Kermanshah Province: Gheshlagh, 1544 m, 34°40'17''N 047°06'41''E, 01.VII. 2015, Malaise trap, M. Zardouei [ HMIM, CZB].

Etymology. The name “ variabilis ” (Latin, adjective, nominative singular feminine) means “variable” and refers to the colouration of palpi, scutellum, abdomen and legs which varies within this species in many different degrees between dark and yellowish.

Diagnosis. Frons in male at its narrowest point 0.84–0.98 and in female 1.07–1.23 times as wide as an eye in dorsal view respectively; fronto-orbital plate in male without proclinate and latero-reclinate orbital setae; palpus varied from basal brownish-yellow and apical dark brown to fully brown; fore claw long, about 1.00–1.30 times as long as tarsomere 5; abdomen without discal setae, with a pale and indistinct dorsal longitudinal vitta; dorsolateral portions of syntergite 1+2 and tergite 3 mostly yellowish-orange, but sometimes more or less darkened up to completely black.

Description. Male (holotype) ( Fig. 2A). Statements given in square brackets refer to the variation found among the paratypes. Overall length: 8.6 [6.8–8.8] mm.

Colouration and microtrichosity. Head predominantly brown; genal dilation with black setulae; frontal vitta brown; lunule and facial ridge brownish-orange; face, gena, parafacial, fronto-orbital plate and occiput covered with grey microtrichosity; upper 1/3 of back of head with 2[1‒4] often irregular rows of black setulae; posteroventral setulae of occiput pale; scape and dorsal portion of pedicel brownish-orange [pedicel rarely entirely brown], other parts of antenna blackish brown; prementum blackishbrown; palpus dark brown in apical half and brownish-yellow basally [dark brown part varies greatly between apical third to full length]; thorax black, predominantly covered with grey microtrichosity, scutum before median suture with 2 lateral semi-triangular and 2 median narrow longitudinal black vittae extending to postalar callus laterally and to first postsutural dorsocentral setae medially (strictly dorsal view); scutellum black with orange apical half [varies from fully black to orange with basal black margin], covered with grey microtrichosity (in dorsal view); wing hyaline; calypter white; tegula and basicosta yellowish-orange; halter yellowish-orange; legs predominantly orange, tarsi black, mid and hind femora entirely orange [sometimes ventral 1/5 of mid and hind femora black], fore femur orange, posterolateral basal third black [varies from black with small yellowish apical anterolateral area to dominant yellow with at least a small black posterolateral basal area]; abdomen entirely covered with grey microtrichosity, with a pale and indistinct dorsal longitudinal vitta; dorsolateral portions of syntergite 1+2 and tergite 3 yellowish-orange [sometimes reduced or entirely black]; tergite 5 black with an orange apical margin [rarely fully black]; terminalia brown, syncercus dark brown.

Head ( Figs 2C‒D). Eye bare; height of gena in lateral view about 0.28 [0.20–0.30] times as long as vertical diameter of eye; face 0.95 [0.90‒1.00] times as long as frons in lateral view; frons at its narrowest point 0.86 [0.84–0.98] times as wide as an eye in dorsal view; frontal vitta medially almost 0.85 [0.80–1.00] times as wide as fronto-orbital plate; medial vertical seta nearly 0.62 [0.55–0.75] times as long as vertical diameter of eye; lateral vertical seta present, about 0.65 [0.55–0.65] times as long as medial vertical setae; ocellar setae proclinate [or latero-proclinate]; postocellar setae parallel, 0.90 [0.80–0.90] times as long as ocellar setae; occiput convex; frons with 10 [10–14] frontal setae descending to base of postpedicel; facial ridge bare, parafacial bare; fronto-orbital plate with a few scattered setulae outside of frontal setae, without proclinate orbital setae and without latero-reclinate orbital seta; fronto-orbital plate at level of scape nearly 0.50 [0.40–0.60] times as wide as transverse diameter of eye; parafacial at its narrowest point almost 0.28 [0.22–0.33] times as wide as transverse eye diameter and 0.90 [0.60–1.00] times as wide as postpedicel in lateral view; vibrissa arising at level of lower facial margin and 0.80 [0.65–0.85] times as long as face; lower facial margin visible in lateral view; postpedicel about 2.00 [1.60–2.60] times as long as pedicel and about 2.10 [1.80–2.90] times as long as wide; arista thickened almost on basal 1/4 [1/5–1/3], first and second aristomeres short, as long as wide; prementum short, about 3.9 [3.0–4.0] times as long as wide; palpus 1.1 [1.0–1.3] times as long as prementum, sub-cylindrical, apically only slightly widened.

Thorax. Prosternum and proepisternum bare; postpronotum with 3 setae, inner seta weaker; scutum with 2+1 acrostichal, anterior small [usually 1+1 acrostichal], 2+3 dorsocentral, 1+3 intra-alar, 2 notopleural, and 3 supra-alar setae; first postsutural supra-alar seta long, nearly as long as posterior notopleural seta; postalar callus with 2 setae; anatergite bare below lower calypter; katepimeron bare; katepisternum with 3 (2+1) setae; one anepimeral seta, well differentiated from adjacent setulae; postmetacoxal area membranous; scutellum with 2 pairs of marginal setae, subapical setae long and divergent, 1.2 [1.0–1.3] times as long as basal setae, apical and lateral marginal setae absent.

Wing. Second costal section with short setulae ventrally; costal seta not differentiated from other costal setae; third costal section almost 1.70 [1.70–2.10] times as long as fourth costal section; fourth costal section (between veins R 2+3 and R 4+5) about 1.90 [1.40–2.70] times as long as second costal section (between subcostal break and vein R 1) and 3.20 [2.30–3.30] times as long as sixth costal section; vein R 4+5 with 2–3 [2–4] basal setulae dorsally and with 2–3 [2–4] basal setulae ventrally; cell r 4+5 open; section of vein M between crossveins r-m and dm-cu about 2.00 [1.80–2.40] times as long as section between dm-cu and bend of M; bend of M forming an obtuse angle without appendix; crossvein dm-cu nearly 4 times as long as crossvein r-m.

Legs. Fore leg: coxa bare on anterior and posterior surfaces; tibia with 2 long posterior setae and with a row of short anterodorsal and a few posterodorsal setae; preapical anterodorsal seta much shorter than very long preapical dorsal seta, preapical posterodorsal seta very short [or indistinct]; tarsomere 1 nearly 1.80 times as long as tarsomere 2 and 0.60 times as long as tibia; claw long, about 1.25 [1.00–1.30] times as long as tarsomere 5. Mid leg: tibia with 1 anterodorsal, 2 posterior and 1 ventral setae. Hind leg: tibia with a nearly complete row of irregular anterodorsal, 3–4 posterodorsal, 2–3 anteroventral and 2 distinct preapical dorsal setae, one strong seta each in size of preapical dorsal setae in the middle of anterodorsal and posterodorsal rows.

Abdomen. Middorsal depression of syntergite 1+2 not extending to posterior margin of that segment; syntergite 1+2 with 1 pair of median marginal, 2‒3 pairs of lateral marginal and 2–4 pairs of lateral discal setae; tergite 3 with 1 pair of median marginal and 1–4 pairs of lateral marginal setae; tergite 3 nearly 0.65 [0.60–0.70] times as long as wide; tergites 4–5 each with a complete row of marginal setae; tergite 5 nearly 0.70 [0.60–0.75] times as long as tergite 4.

Terminalia ( Fig. 3). Sternite 5 nearly as long as wide, with a deep median V-shaped depression posteriorly, each lobe with one tooth ( Fig. 3E); syncercus and surstylus as in Figures 3A‒B, surstylus curved inwards in a hook shape; pregonite hook shaped, without setulae ( Fig. 3C); postgonite rudimentary, tiny; aedeagus with an epiphallus dorsobasally ( Fig. 3D).

Female ( Figs 2B, 4A). Body length 6.1–9.2 mm. Differs from male as follows: mid and hind femora almost entirely orange; frons at its narrowest point 1.07–1.23 times as wide as an eye in dorsal view; frontal vitta medially almost 0.6 times as wide as fronto-orbital plate; frons with 7–10 frontal setae; fronto-orbital plate with 1 upper latero-reclinate and two proclinate orbital setae.

Remarks. We studied the catalogue of O’Hara & Wood (2004) and the descriptions of the species with Nearctic distributions ( Bigot, 1889; Coquillett, 1895, 1897, 1910; Townsend, 1908; Reinhard, 1967) and found no species identical with Solieria variabilis sp. nov.. The males of Solieria variabilis sp. nov. have a body length of 6.8‒8.8 mm and are larger on average than those of other Palaearctic species. Males of S. borealis , S. pacifica and S. vacua differ from males of Solieria variabilis sp. nov. by their fronto-orbital plate with proclinate and latero-reclinate orbital setae. The new species resembles S. aureola , S. fenestrata , S. inanis , S. munda and S. murina in the lack of such orbital setae ( Figs 2C‒D). The frons of S. variabilis sp. nov. at its narrowest point in the male is 0.84‒0.98 times as wide as an eye in dorsal view ( Fig. 2D) and therefore is much wider than in males of S. aureola , S. inanis , S. munda and S. murina with frons 0.3–0.6 times as wide as an eye. Solieria variabilis sp. nov. is most similar to S. fenestrata in morphological characters and structure of the male terminalia ( Fig. 5A). Since the two species S. fenestrata and S. pacifica have also been found in the Middle East ( Table 1), their differences to S. variabilis sp. nov. is described here in more detail. The frons of S. variabilis sp. nov. in male at its narrowest point is 0.84‒0.98 times as wide as an eye in dorsal view and therefore wider than in males of S. fenestrata with frons 0.6‒0.8 times as wide as an eye. Also the coloration of abdomen is different. Abdominal tergites 2‒4 in S. fenestrata are yellowish-orange with dorsal longitudinal black vitta ( Fig. 4B) while in S. variabilis they are entirely black or black with yellowish-orange dorsolateral portions of syntergite 1+2 and tergite 3. The males of S. variabilis sp. nov. are easy to distinguish from males of S. pacifica . The latter has wider frons with proclinate and latero-reclinate orbital setae ( Fig. 4D), short fore claw, and different male terminalia ( Fig. 5B), but the colouration of abdomen is similar ( Figs 2A, 4D).