Dolichocephala incus, Sinclair & Plant, 2017

Sinclair, Bradley J. & Plant, Adrian R., 2017, Dolichocephala Macquart of Thailand (Diptera: Empididae: Clinocerinae), Zootaxa 4358 (3), pp. 551-568 : 556-557

Dolichocephala incus sp. nov.

( Figs 4 , 10, 11, 20, 26)

Type material. HOLOTYPE, ♂ labelled: “THAILAND: Chiang Mai/ Doi Inthanon NP Kew Mae Pan/ 18°33.163′ N98°28.8′E 2200m / Malaise Trap, 27.ix.–5.x.2006 / Y. Areeluck leg. T350”; “HOLOTYPE/ Dolichocephala / incus / Sinclair & Plant [red label]” (QSBG). PARATYPES: THAILAND. Chiang Mai Province: Doi Inthanon NP, Kew Maepan Trail, 18°33.162′N 98°28.81′E, 2200 m, MT, 23.ii.–2.iii.2007, Y. Areeluck leg. T1771 (1 ♂, 2 ♀, QSBG); Doi Inthanon NP, Kew Maepan Trail, 18°33.162′N 98°28.81′E, 2200 m, MT, 8–15.xii.2006, Y. Areeluck leg. T1878 (1 ♂, 1 ♀, CNC); Doi Inthanon NP, Kew Maepan Trail, 18°33.162′ N98°28.81′E, 2200 m, MT, 9–16.ii.2007, Y. Areeluck leg. T1795 (1 ♀, CNC); Doi Inthanon NP, Summit marsh, 18°35.361′ N98°29.157′E, 2500 m, MT, 29.iv.–6.v.2007, Y. Areeluck leg. T1852 (1 ♂, CNC); Doi Inthanon NP, Kew Mae Pan, 18°33.163′N 98°28.8′E, 2200 m, MT, 12–19.x.2006, Y. Areeluck leg. T370 (2 ♂, CNC); Doi Inthanon NP, Kew Maepan Trail, 18°33.162′N 98°28.81′E, 2200 m, MT, 16–23.iii.2007, Y. Areeluck leg. T1929 (3 ♀, CNC); Doi Inthanon NP, Summit marsh, 18°35.361′N 98°29.157′E, 2500 m, MT, 23.ii.–2.iii.2007, Y. Areeluck leg. T1770 (1 ♂, CNC); Doi Inthanon NP, Kew Maepan Trail, 18°33.162′N 98°28.81′E, 2200 m, MT, 12– 19.i.2007, Y. Areeluck leg. T1931 (1 ♂, 3 ♀, CNC); Doi Inthanon NP, Summit marsh, 18°35.361′N 98°29.157′E, 2500 m, MT, 1–8.v.2007, Y. Areeluck leg. T1823 (1 ♂, QSBG); Doi Inthanon NP, summit marsh, 18°35.361′N 98°29.157′E, 2500 m, MT, 15–22.vii.2006, Y. Areeluck leg. T70 (1 ♀, QSBG); Doi Phahompok NP, Kiewlom2/ Montane Forest, 20°3.426′N 99°8.553′E, 2112 m, MT, 14–21.ix.2007, P. Wongchai leg. T6160 (1?, QSBG).

Additional material. THAILAND. Chiang Mai Province: Doi Inthanon NP, Kiew Maepan, 18.55817°N 98.48103°E, 2210 m, moist hill evergreen forest, MT, multiple dates 2014, Srisuka & Plant leg. QSBG-2014–09, 2014–83, 2014–156, 2014–214, 2014–215, 2014–273 (4 ♂, 5 ♀); Doi Inthanon NP, summit (behind office), 18.58689°N 98.48723°E, 2534 m, moist hill evergreen forest, MT, multiple dates 2014, Srisuka & Plant leg. QSBG-2014–07, 2014–78, 2014–125, 2014–126, 2014–233, 2014–269, 2014–270 (13 ♂, 8 ♀); Doi Inthanon NP, summit (Angka) 18.58892°N 98.48481°E, 2545 m, Rhododendron scrub in moist hill evergreen forest at edge of Sphagnum bog, MT, multiple dates 2014, Srisuka & Plant leg. QSBG-2014–08, 2014–57, 2014–80, 2014–127, 2014–155, 2014–271, 2014–287, 2014–323 (26 ♂, 17♀).

Recognition. This is a brown species distinguished by the short R2+3, ending in costa well proximal to branching of radial fork, short auxiliary crossvein and anvil-shaped distiphallus.

Description (wing length 1.8–1.9 mm). Male. Head: Slender, tapered ventrally. Clypeus and face with greyish pruinescence, extending dorsally to near base of ocellar triangle; occiput subshiny, lacking pruinescent stripe. Ocellar triangle with pair of stout upturned setae. Antenna light brown.

Thorax: Scutum brown, subshiny, without bluish pruinescent medial stripe. Pleura with whitish pruinescent stripe from just above fore coxa straight posteriorly to below posterior spiracle. Several very minute acrostichals anterior to first dc; 5 dc; 1 pprn; 1 presut spal; 1 upper npl, lower npl short, slender; 1 pal; 2 sctl, distinctly shorter than prescutellar dc. Laterotergite with several brownish setulae.

Legs: Fore coxa, femora and tibiae yellow, tarsi darkening apically; mid and hind coxae brown, concolourous with pleura.

Wing (Fig. 11): Narrow; infuscate; single long basal costal seta present; base of R4 straight, joining R5 at nearly right angles; base of cell r4 truncate; R4 nearly straight, with long auxiliary crossvein connecting to R2+3 nearly twice length of base of R4; R2+3 short, ending in costa proximal to base of R4 and auxiliary crossvein; irrorations distinct: base of cell r1 with slender spot; 2 large spots in cell r2+3; one spot each in cells r4, m1, m2 and m4; cell r5 with 2 distinct subapical spots; cell dm without distinct spot; cell bm infuscate. Halter pale white.

Abdomen: Sclerites brown, shiny, concolourous with thorax. Terminalia ( Fig. 4 ): Robust. Hypandrium subtriangular, with 3 lateral setae. Phallus arched, base robust with posterolateral ridge, well sclerotized; apical half with pale, divergent, membranous lateral ridge; distiphallus sclerotized, anvil-shaped; apex membranous tapered apically. Ejaculatory apodeme slender. Epandrium rounded with several long marginal dorsal setae. Clasping cercus subtriangular, tapered to rounded apex, arched medially; outer face with 2 long setae. Cercal plate with 2 long setae. Lobe of subepandrial sclerite present, hooked tip extended beyond surstylus and epandrium. Surstylus sickle-shaped, long, slender and arched apically, outer margin with long setae.

Female. Similar to male. Cercus long, length about 2X basal width.

Etymology. The species name is from the Latin incus (anvil), a noun in apposition and is reference to the shape of the distiphallus.

Distribution. This species is restricted to moist hill evergreen forest biotopes at or above 2,100 m on the summit areas of the mountains Doi Inthanon (Thanon Thongchai Range) and Doi Phahompok (Daen Lao Range) in northern Thailand ( Fig. 20 ).

Remarks. Peak adult activity apparently occurs at the start of the dry season in January and the early monsoon period in May ( Fig. 26 ).

Figures

FIGURE 26. Phenology of adult abundance of Dolichocephala incus sp. nov. caught on Doi Inthanon and Doi Phahompok.

FIGURES1–4. Male terminaliaof Dolichocephala spp.inThailand,lateral view.1. D.bicolor sp.nov.; 2. D.curvatasp. nov.; 3. D. immaculata sp. nov.; 4. D. incus sp. nov. Scale bars = 0.1 mm. Abbreviations: cl cerc—clasping cercus; distphdistiphallus; sbepand scl—subepandrial sclerite.

FIGURES 17–23. Distribution of Dolichocephala spp. in Thailand at a resolution of 0.25° of latitude and longitude with symbols scaled to 0.5°. 17. D. bicolor sp. nov.; 18. D. curvata sp. nov.; 19. D. immaculata sp. nov.; 20. D. incus sp. nov.; 21. D. longicercasp. nov.; 22. D. srisukai sp.nov.; 23. D. thailandensis sp. nov.