Dolichocephala longicerca, Sinclair & Plant, 2017

Sinclair, Bradley J. & Plant, Adrian R., 2017, Dolichocephala Macquart of Thailand (Diptera: Empididae: Clinocerinae), Zootaxa 4358 (3), pp. 551-568 : 557-559

Dolichocephala longicerca sp. nov.

( Figs 5 , 12, 21)

Type material. HOLOTYPE, ♂ labelled: “THAILAND: Chiang Mai/ Doi Inthanon NP Summit marsh/ 18°35.361′ N98°29.157′E/ MT, 9–16.ii.2007; 2500m / Y. Areeluck leg. T1794”; “HOLOTYPE/ Dolichocephala / longicerca / Sinclair & Plant [red label]” (QSBG). PARATYPE: THAILAND. Chiang Mai Province: Doi Inthanon NP, Kew Mae Pan, 18.55817°N 98.48103°E, 2200 m, MT, 6.xii.2013 – 14.i. 2014, Srisuka & Plant leg. QSBG-2014–09 (1 ♀, QSBG).

Recognition. This is a brown species distinguished by the spot in cell r2+3, at least two spots in cell m4 and the elongate clasping cercus with hooked apex.

Description (wing length 1.7 mm). Male. Head: Slender, tapered ventrally. Clypeus and face with greyish pruinescence, extending dorsally as narrow stripe around ocellar triangle and joining to form “V” on upper occiput. Ocellar triangle with pair of stout upturned setae. Antenna brown.

Thorax: Scutum brown, subshiny, with bluish pruinescent medial stripe anteriorly. Specimen damaged, shrunken, scutal and pleural details not clearly visible. Laterotergite with several brownish setulae.

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

Wing (Fig. 12): Narrow; infuscate; single long basal costal seta present; base of R4 straight, joining R5 at nearly right angles; base of cell r4 truncate; R4 slightly sinuous, with long curved auxiliary crossvein connecting to R2+3 slightly longer than length of base of R4; R2+3 short, ending in costa just proximal to or nearly opposite to base of R4; irrorations distinct: base of cell r1 with slender spot; two large spots in cells r2+3 (proximal section), m2, m4 and dm; one spot each in cells r2+3 (distal section) and r4; three spots in cell m1; cell r5 with 2–3 distinct subapical spots; cell bm infuscate. Halter brown.

Abdomen: Sclerites brown, shiny, concolourous with thorax. Terminalia ( Fig. 5 ): Hypandrium elongate, cylindrical and arched, with 3 lateral setae. Phallus strongly bent sub-basally, well sclerotized, arched posteriorly; distiphallus with sclerotized cap, membranous convoluted sac beneath cap. Ejaculatory apodeme slender. Epandrium rounded with several long, stout marginal dorsal setae. Clasping cercus elongate, digitiform with hooklike apex, bearing several short apical setae and several subapical setae subequal to width of cercus; apex with peglike inner seta. Cercal plate with 2 long setae. Lobe of subepandrial sclerite slender with tapered apex, projecting slightly beyond surstylus and epandrium. Surstylus very slender, slightly arched, without marginal setae.

FIGURES 8–12. Habitus and wing images of Dolichocephala spp. in Thailand. 8. D. bicolor sp. nov., female, lateral view; 9. D. bicolor sp. nov., male, dorsal view; 10. D. incus sp. nov., female, lateral view; 11. D. incus sp. nov., wing; 12. D. longicerca sp. nov., female, lateral view. Scale bars = 1 mm. Abbreviations: R2+3—second branch of radius; R4—third branch of radius.

Female. Not examined.

Etymology. The species name is in reference to the elongate clasping cercus. Distribution. This species is restricted to moist hill evergreen forest biotopes at or above 2,200 m on the

summit areas of the mountain Doi Inthanon (Thanon Thongchai Range) in northern Thailand ( Fig. 21 ). Remarks. Adults were captured between December and February indicating activity during the latter part of

the cold season and during the dry season.

Figures

FIGURES 5–7. Male terminalia of Dolichocephala spp. in Thailand, lateral view. 5. D. longicerca sp. nov.; 6. D. srisukai sp. nov.; 7. D. thailandensis sp. nov. Scale bars = 0.1 mm. Abbreviations: cl cerc—clasping cercus; distph—distiphallus; phphallus.

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.