Clinocera gracilis, Sinclair & Plant, 2022

Sinclair, Bradley J. & Plant, Adrian R., 2022, Clinocera Meigen of Thailand (Diptera: Empididae: Clinocerinae), Zootaxa 5200 (6), pp. 525-549 : 532-533

Clinocera gracilis sp. nov.

( Figs 4 , 8–10 , 20 , 24 )

urn:lsid:zoobank.org:act:70E1014D-FA33-4ECC-ACB4-DC49D43F9D81

Type material. HOLOTYPE, ♂ labelled: “ THAILAND: Loei Province / Phu Hin Rong Kla Nat. Park / Huai Man Daeng Noi at trail / 16°57′N 101°03′E, 1600 m / 14.xii.2002 – 17.i.2003, Malaise ”; “HOLOTYPE/ Clinocera / gracilis/ Sinclair & Plant [red label]” ( QSBG) . PARATYPES: THAILAND. Loei Province: same data as holotype (1 ♂, CNC) ; same data as holotype except, 14.xi.–14.xii.2002 (5 ♂, 2 ♀, CNC; 1 ♂, 1 ♀, ISUI) ; same data as holotype except, v.2002 – i.2003 (1 ♀, CNC) ; same data as holotype except, 22–23.vii.2002 (1 ♂, ISUI) ; same data as holotype except, 10.ii.–17.iii.2003 (1 ♀, CNC) ; same data as holotype except, 21.x.–18.xi.2002 (1 ♀, CNC) ; T535 (1 ♀, CNC) . Kamphaeng Phet Province: T6303 (1 ♀, QSBG) ; T6304 (1 ♂, QSBG) ; T3679 (1 ♀, QSBG) ; T6299 (1 ♂, QSBG) . VIETNAM. Vinh Phú, Tam Dao, Hill Stn. , SE town , 930 m, 21°27′N 105°39″E, MT, primary for, dry streambed, 7–31.v.1996, B. Hubley (11 ♂, 7 ♀, ROM) ; Con Tum, edge of Nhoc Mi River , 2 kmS Ngoc Linh , 15°05′14.8″N 107°55′38.9″E, MT, riparian veg., 7–12.ix.1998, D.C. Currie (2 ♀, ROM) .

Additional material examined. THAILAND. Nakhon Si Thammarat: T4306 (1 ♂, 1 ♀, QSBG).

Recognition. This species is distinguished from the other Thailand species of Clinocera by the faint bluish pruinescence on face extending dorsally between antennae to ocellar triangle; pleura with whitish pruinescent band along dorsal margin of katepisternum and lateral margin of scutum; pleura dark brown, contrasting with yellow coxae and yellowish brown femora; fore femur with long, slender anteroventral and posteroventral rows of setae, length subequal to width of femur; male clasping cercus dark, slender and arched.

Description (wing length 2.1–2.5 mm). Male. Head: Oval, dark brown. Face narrower than width of antennal bases, narrower at mid-length, without lateral setulae; lower third of face with bluish pruinescence tapered to median stripe between antennal bases to ocellar triangle ( Fig. 4 ). Ocellar triangle with pair of divergent ocellar setae, longer than pair of vertical setae. Antenna brown; arista-like stylus nearly 2.5 times length of remaining antenna. Thorax: Scutum brown, with thin pruinescence, lateral margin from postpronotal lobe to notopleuron with whitish pruinescence; dark spot at base of wing ( Fig. 9 ). Pleura brown with thin pruinescence; whitish pruinescent band along dorsal margin of katepisternum (in oblique view). Several very minute acrostichals anterior to first dc; 5 dc; 1 pprn, strong, similar to dc; 1 presut spal; 1 strong upper npl, lower npl slender; 1 posterior psut spal; 1 pal; 2 sctl, similar to prescutellar dc. Laterotergite with several brownish setae. Legs: Coxae yellow and ventral faces of femora yellowish brown, remaining segments brown. Fore femur with anteroventral and posteroventral rows of long, slender, pale setae, length nearly subequal to width of femur. Hind tibia with strong dorsal and ventral setae on distal third, length nearly subequal to width of tibia. Wing: Narrow; infuscate; pterostigma absent; single long basal costal seta present; cell dm produced distally. Halter pale brown. Abdomen: Sclerites dark brown, with thin pruinescence, similar shade to thorax; tergite 7 thinly sclerotized medially. Terminalia ( Figs 8 , 10 ): Hypandrium triangular, subequal in length with epandrium, tapered distally, without lateral setae. Phallus straight with expanded apex of shaft and horn-like expansion posteriorly; distiphallus flattened, arched apically, more than one-half length of shaft. Ejaculatory apodeme small, slender. Epandrium oval, with short, thin setae. Clasping cercus very narrow, darkly pigmented, gently arched digitiform, flattened, with tapered apex; peg-like setae on inner apex. Surstylus triangular, tapered to rounded or pointed apex, posterior margin without prominent crest.

Female. Similar to male, except as follows: fore femur with anteroventral row of short, dark setae.

Etymology. This species is named in reference to the slender clasping cercus.

Distribution and Ecology. Clinocera gracilis sp. nov. appears to favour mid-elevations (930–1,600 m) and has a wide distribution covering north, northwest and peninsular Thailand and two broadly separated locations in the north and south-central regions of Vietnam ( Fig. 24 ). The record from Nakhon Si Thammarat in southern Thailand is south of the Isthmus of Kra, indicating that the species has crossed this significant biogeographic boundary. Adults have been captured in northern Thailand during January and March (hot dry season), July (wet season), November and December (cold dry season), whereas the Nakhon Si Thammarat specimens were taken in April when conditions were wet ( Fig. 20 ).

Remarks. This species is very similar to C. chilamche Smith from Nepal in colour patterns and slender clasping cercus (differs by shape of apex of phallic shaft and shape of surstylus). Also the shape of the clasping cercus is similar to the Chinese species C. sinensis Yang & Yang and C. wui Yang & Yang , but the shape of the surstylus differs (unfortunately details of the phallic shaft were not illustrated for the latter two species).

Figures

FIGURE 20. Phenology of Clinocera univittata sp. nov. and C. gracilis sp. nov. Adult abundance (note log10 scale) is plotted against month number (1–12 = January–December).

FIGURES 1–4. Species of Thailand Clinocera. 1, C. abbreviata sp. nov., head, thorax, foreleg, lateral view, scale bar = 0.25 mm; 2, C. areeluckorum sp. nov., male habitus, lateral view, scale bar = 0.5 mm; 3, C. courtneyi sp. nov., face, frontal view, scale bar = 0.25 mm; 4, C. gracilis sp. nov., head, oblique anterior view, scale bar = 0.25 mm. Abbreviations: oc s – ocellar seta(e).

FIGURES 5–8. Male terminalia of Thailand Clinocera, lateral view. 5, C. abbreviata sp. nov.; 6, C. areeluckorum sp. nov.; 7, C. courtneyi sp. nov.; 8, C. gracilis sp. nov. Abbreviations: cerc pl—cercal plate; cl cerc—clasping cercus; distph—distiphallus; ej apod—ejaculatory apodeme; epand—epandrium; hypd—hypandrium; ph—phallus; sur—surstylus. Scale bars = 0.1 mm

FIGURES 9–12. Species of Thailand Clinocera. 9, C. gracilis sp. nov., head, thorax, foreleg, lateral view, scale bar = 0.25 mm; 10, C. gracilis sp. nov., male terminalia, oblique view, scale bar = 0.1 mm; 11, C. rostrata sp. nov., male habitus, lateral view, scale bar = 0.5 mm; 12, C. spatulata sp. nov., head, thorax, lateral view, scale bar = 0.25 mm.

FIGURES 21–28. Distribution of new Clinocera species in East Asia. 21, C. abbreviata sp. nov., 22, C. areeluckorum sp. nov., 23, C. courtneyi sp. nov., 24, C. gracilis sp. nov., 25, C. univittata sp. nov., 26, C. rostrata sp. nov., 27, C. spatulata sp. nov., 28, C. srisukai sp. nov. Occurrence data for each species is plotted with an accuracy of one degree (1°) of latitude and longitude.