Clistoabdominalis hyrcania, Kazerani & Kehlmaier, 2018

Kazerani, Farzaneh & Kehlmaier, Christian, 2018, A new species of the genus Clistoabdominalis Skevington (Diptera: Pipunculidae) from Iran, with a key to the Western Palaearctic species of the Clistoabdominalis ruralis group, Zootaxa 4425 (3), pp. 582-588 : 583-587

Clistoabdominalis hyrcania sp. nov.

Type material. HOLOTYPE: Golestan province, Shast-Kola ; 36°44'1'' N, 54°23'53'' E, 849 m, 10.viii.2017, 1♂, leg. F. Kazerani, coll. RIFR.

Description. MALE ( Figs 2 , 3 ). Body length 3.2 mm; wing length 3.5 mm; eyes meeting for a slightly shorter distance (0.7 times) than frons length. Head. Face and frons greyish white dusted, parallel-sided. Clypeus greyish white dusted ( Fig. 2b ). Palpus about 1/8 the height of eye, yellowish white with dark tip ( Fig. 2b ). Proboscis yellowish brown with light apical hairs ( Fig. 2b ). Occiput greyish white dusted. Antenna with pedicel dark brown, with 2–3 minute dorsal and ventral bristles. Postpedicel pointed, yellowish brown with white outer border, about 2.5× as long as deep (in its widest part). Arista about 2× as long as postpedicel, dark brown, with thickened base ( Fig. 2b ). Thorax. Black, narrowly golden dusted along dorsal, frontal and lateral margins. Postpronotal lobe yellow. Pleura greyish dusted. Scutellum dark brown, slightly greyish dusted. Wing. Membrane very slightly and evenly infuscated ( Fig. 2a ); covered with microtrichia except at base; pterostigma brown and complete; third costal segment about 0.6× as long as fourth costal segment, cross vein r-m reaches cell dm at 1/3 of its length, apical section of R4+5 about 3.5× as long as proximal section, halter white with darkened knob. Legs. Coxae and trochanters brown, fore and mid femora dark brown except yellow in apical 1/5, femora lacking any distinct ventral black spines; tibia mostly yellow, fore and mid tibia brown in apicoventral half, hind tibia brown in basal half, tarsal segments yellow except distitarsus; pulvilli shorter than distitarsus ( Fig. 2a ). Abdomen. Tergites 2–5 mostly dusted dorsally, with silver posterolateral patches extending onto posterior corners of dorsum; silver dusting most extensive dorsally on tergite 1. Sternites 2–5 dark brown and rectangular in dorsal view, covered by scattered minute bristles; sternite 6 pollinose and swollen internally. Genitalia. Epandrium dark brown and asymmetrical ( Fig. 3c ); wrapping around dorsally and visible in dorsal view. Cerci yellow. Surstyli yellowish brown; in strictly dorsal view pointed apically with yellow bristles; both surstyli boot-shaped in dorsal view; right surstylus with a medial protuberance; left surstylus without protuberance medially ( Figs 2d , 3d ). In lateral view, both surstyli with a triangular apicoventral projection and a short finger-like apex ( Figs 2e–f , 3e–f ). In ventral view, gonopods subequal, right one clearly longer ( Figs 2c , 3a ); phallic guide straight, rather short, cone-shaped, and with a small hook-like apex in lateral view ( Figs 3a–b ); phallus trifid and gently bent ( Fig. 3a ). FEMALE. Unknown.

Differential diagnosis. Due to its strong resemblance with C. dilatatus , known from western and central Europe and redescribed and illustrated by Kehlmaier (2005a), C. hyrcania sp. nov. is attributed to the C. ruralis species group. Among other features, the C. ruralis group lacks a ventral projection on the syntergosternite 8 (present in the C. electus group), and has a non-deflected hypandrium (basally deflected by about 90° in the C. trochanteratus group). The males of C. hyrcania sp. nov. can be separated from those of C. dilatatus by comparing the lateral shape of the surstyli (see Figs 2e–f and 3e–f , in comparison with Kehlmaier 2005a: figs 9i and 9k). In lateral view, both species exhibit a ventroapical triangular projection on both surstyli which is more pronounced in C. hyrcania sp. nov. ( Figs 3e–f ). In addition, the actual apices of the surstyli are more elongated, a feature that can also be observed from strictly dorsal view ( Fig. 3d ).

Etymology. The specific epithet ‘ hyrcania ’ is the Persian spelling of Hyrkania [Үρκανία], the Greek noun for the historical region composed of the land south-east of the Caspian Sea, where the type locality of the new species is found. It is to be treated as a noun in apposition.

An identification key to the males of the Clistoabdominalis ruralis species group from the Western Palaearctic region

1 Left surstylus in lateral view with an apicoventral projection ( Figs 1f , 2f ; Kehlmaier 2005a: Figs 9k, 11l)............... 2 - Left surstylus in lateral view without an apicoventral projection................................................ 4 2 Left surstylus in lateral view with an apicoventral projection situated at its apex ( Kehlmaier 2005a: Fig. 11l). Right surstylus shaped differently, with blunt apex ( Kehlmaier 2005a: Fig. 11j).................................. C. ruraliS (Meigen) (Distribution: a widespread Palaearctic species, apparently absent from boreal/subarctic regions.)

- Left surstylus in lateral view with an apicoventral projection situated clearly before its apex ( Figs 1f , 2f ). Right surstylus almost shaped identical............................................................................... 3

3 Apicoventral projections of surstyli large ( Figs 1e–f )..... C. hyrcania sp. nov. (Distribution: only known from northern Iran)

- Apicoventral projections of surstyli small ( Kehlmaier 2005a: Figs 9i, k)..................................................................... C. dilatatuS (De Meyer) (Distribution: restricted to France, Portugal, Spain and Switzerland)

4 In strictly dorsal view, both surstyli are sickle shaped, with a long inner fingerlike projection ( Kehlmaier 2005a: Fig. 10j)..................................................................................... C. imitator (De Meyer) (Distribution: Mediterranean species, known from France, Israel, Portugal and Spain)

- In strictly dorsal view, both surstyli are of different shape, the left one being roughly triangular ( Kehlmaier 2005a: Fig. 1 2f ; Kehlmaier 2005b: Fig. 9c)............................................................................. 5

5 Syntergosternite 8 without a membranous area. In dorsal view, fingerlike projection of right surstylus narrow ( Kehlmaier 2005b: Fig. 9a). Phallic guide shorter and broader than in the following species ( Kehlmaier 2005b: Fig. 9c)........................................................ C. SinaienSiS (De Meyer) (Distribution: only known from Egypt and Iran)

- Syntergosternite 8 with a membranous area. In dorsal view, fingerlike projection of right surstylus rather broad ( Kehlmaier 2005a: Fig. 12f). Phallic guide longer and narrower than in the above species ( Kehlmaier 2005a: Fig. 12a)................................................. C. tumiduS (De Meyer) (Distribution: France, Greece, Italy, Spain and Switzerland)

Figures

FIGURE 1. A typical aspect of the Shast-Kola forest where the holotype of Clistoabdominalis hyrcania sp. nov. was collected.

FIGURE 2. Clistoabdominalis hyrcania sp. nov.. a: male habitus, lateral view. b: head, lateral view. c: male genitalia capsule, ventral view. d: surstyli, strictly dorsal view. e: right surstylus lateral view. f: left surstylus, lateral view.

FIGURE 3. Clistoabdominalis hyrcania sp. nov.. a: male genitalia capsule, ventral view. b: phallic guide, lateral view. c: syntergosternite 8 and ejaculatory apodeme, dorsal view. d: surstyli, strictly dorsal view. e: right surstylus lateral view. f: left surstylus lateral view. Scale bars: 0.1 mm.