Clinocera abbreviata, Sinclair & Plant, 2022

Clinocera abbreviata View in CoL sp. nov.

( Figs 1 View FIGURES 1–4 , 5 View FIGURES 5–8 , 19 View FIGURE 19 , 21 View FIGURES 21–28 )

urn:lsid:zoobank.org:act:F5163A91-CC66-4B24-86F1-AEAF976A772F

Type material. HOLOTYPE, ♂ labelled:“ THAILAND: Chiang Mai / Doi Inthanon NP summit marsh / 18°35.361′N 98°29.157′E 2500m / Malaise trap 2–10.xi.2006 / Y. Areeluck leg. T386” ; “HOLOTYPE/ Clinocera / abbreviata/ Sinclair & Plant [red label]” ( QSBG) GoogleMaps . PARATYPES: THAILAND. Chiang Mai Province: T386 (5 ♂, 8 ♀, CNC; 7 ♂, 17 ♀, QSBG) .

Additional material examined. THAILAND. Chiang Mai Province: T38 (2 ♂); T64 (2 ♂); T65 (12 ♂, 2 ♀); T66 (1 ♂); T71 (11 ♂, 2 ♀); T118 (7 ♂, 5 ♀); T119 (4 ♂, 3 ♀); T124 (2 ♂, 6 ♀); T177 (3 ♂); T184 (2 ♂, 1 ♀); T233 (1 ♂); T239 (12 ♂, 14 ♀); T240 (15 ♂, 48 ♀); T246 (491 specimens); T247 (1 ♂, 2 ♀); T251 (1534 specimens); T253 (22 ♂, 88 ♀); T341 (3 ♀); T343 (1 ♂, 5 ♀); T344 (1018 specimens); T345 (124 ♂, 193 ♀), (544 specimens); T346 (47 ♂, 167 ♀); T350 (306 ♂, 271 ♀), (1341 specimens); T351 (104 ♂, 130 ♀), (1158 specimens); T352 (31 ♂, 124 ♀); T353 (1 ♂); T362 (1 ♀); T363 (2 ♂, 9 ♀), (694 specimens); T364 (53 ♂, 50 ♀); T370 (53 ♂, 89 ♀); T374 (15 ♂, 15 ♀); T375 (1 ♂, 4 ♀); T380 (5 ♂, 9 ♀); T1771 (2 ♂, 2 ♀); T1794 (7 ♂, 6 ♀); T1806 (4 ♂, 5 ♀); T1812 (2 ♂, 14 ♀); T1813 (1 ♂, 1 ♀); T1823 (2 ♀); T1840 (12 ♂, 26 ♀); T1844 (1 ♂); T1846 (2 ♂, 3 ♀); T1847 (3 ♂, 2 ♀); T1852 (43 ♂, 64 ♀); T1853 (8 ♂, 18 ♀); T1860 (2 ♂, 7 ♀); T1877 (3 ♂, 6 ♀); T1878 (2 ♂, 9 ♀); T1893 (1 ♂, 4 ♀); T1929 (1 ♂); T1931 (2 ♀); T1950 (6 ♂, 9 ♀); T1951 (1 ♂, 1 ♀); T6160 (1 ♀); QSBG-2014-6 (2 ♀); QSBG-2014-7 (1 ♀); QSBG-2014-8 (2 ♀); QSBG-2014-9 (5 ♂, 13 ♀); QSBG-2014-25 (1 ♂, 1 ♀); QSBG-2014-55 (2 ♀); QSBG-2014-56 (4 ♀); QSBG-2014-57 (2 ♂, 3 ♀); QSBG-2014-79 (10 ♂, 41 ♀); QSBG-2014-80 (93 ♂, 166 ♀); QSBG-2014-83 (3 ♀); QSBG-2014-125 (8 ♂, 22 ♀); QSBG-2014-126 (189 ♂, 83 ♀); QSBG-2014-127 (104 ♂, 42 ♀); QSBG-2014-129 (2 ♂, 1 ♀); QSBG-2014-153 (1 ♂, 5 ♀); QSBG-2014-154 (191 ♂, 71 ♀); QSBG-2014- 155 (130 ♂, 97 ♀); QSBG-2014-156 (13 ♂, 15 ♀); QSBG-2014-157 (99 ♂, 74 ♀); QSBG-2014-176 (15 ♂, 1 ♀); QSBG-2014-177 (17 ♂, 4 ♀); QSBG-2014-179 (23 ♂, 7 ♀); QSBG-2014-212 (2 ♂); QSBG-2014-213 (2 ♂, 3 ♀); QSBG-2014-214 (2 ♂); QSBG-2014-215 (9 ♂, 5 ♀); QSBG-2014-232 (21 ♂, 59 ♀); QSBG-2014-233 (174 ♂, 438 ♀); QSBG-2014-234 (24 ♂, 57 ♀); QSBG-2014-269 (60 ♂, 79 ♀); QSBG-2014-270 (359 ♂, 878 ♀); QSBG-2014-271 (137 ♂, 216 ♀); QSBG-2014-272 (6 ♂, 9 ♀); QSBG-2014-273 (269 ♂, 165 ♀); QSBG-2014-285 (3 ♂); QSBG-2014-286 (2 ♂, 12 ♀); QSBG-2014-287 (13 ♂, 23 ♀); QSBG-2014-288 (68 ♂, 53 ♀); QSBG-2014-323 (1 ♂); QSBG-2014-325 (2 ♀) (divided between CNC and QSBG).

Recognition. This species is distinguished from the other Thailand species of Clinocera by the ocellar setae shorter than the vertical setae; dark pleura; clasping cercus with straight apical margin.

Description (wing length 2.4–2.8 mm). Male. Head: Oval, dark brown. Face narrower than width of antennal bases, slightly narrower at mid-length, with lateral setulae; pale bluish pruinescence covering entire lower face, tapered to antennal bases, faded between antennal bases to ocellar triangle. Ocellar triangle with pair of divergent ocellar setae, shorter than inner vertical setae ( Fig. 1 View FIGURES 1–4 ). Antenna brown; arista-like stylus less than twice length of remaining antenna. Thorax: Scutum brown, with thin pruinescence; yellow on postpronotal lobe and postalar ridge; dark spot at base of wing. Pleura brown with thin pruinescence. Several very minute acrostichals anterior to first dc; 5 dc; 1 pprn, thin and reduced; 1 presut spal; 1 strong upper npl, lower npl slender, similar to pprn; 1 posterior psut spal; 1 pal, thin; 2 sctl, similar to prescutellar dc. Laterotergite with several brownish setae. Legs: Coxae and ventral faces of femora yellow, remaining segments brown. Fore femur with anteroventral and posteroventral rows of short, slender, dark setae, length variable from one-half to one-quarter width of femur. Hind tibia with strong dorsal and ventral setae on distal half, nearly subequal to width of tibia. Wing: Narrow; infuscate; pterostigma absent; single long basal costal seta present; cell dm produced distally. Halter yellowish brown. Abdomen: Sclerites dark brown, with thin pruinescence, similar shade to thorax. Terminalia ( Fig. 5 View FIGURES 5–8 ): Hypandrium triangular, similar size to epandrium, tapered distally, without lateral setae. Phallus straight with expanded apex of shaft and rounded expansion posteriorly with narrow crest lower on shaft; distiphallus slender, arched apically with expanded tip, more than one-half length of shaft. Ejaculatory apodeme slender. Epandrium rectangular, with long, thin setae. Clasping cercus digitiform, flattened, with straight apical margin; inner face with peg-like setae confined to extreme anterior and dorsal margins. Surstylus rectangular, with rounded anterior apex, with narrow lateral ridge; dorsal margin without prominent posterior crest.

Female. Similar to male, except as follows: face dull brown; fore femur without row of posteroventral setae.

Etymology. This species is named in reference to the shortened ocellar setae.

Distribution and Ecology. Clinocera abbreviata sp. nov. is only known from Northern Thailand ( Fig. 21 View FIGURES 21–28 ). It is extremely abundant on the mountain Doi Inthanon (10,803 specimens) where it occurs in MHE habitats above 2,200 m and rarely (<0.1% of abundance) at lower elevations in EM and DL habitats.A single female specimen was collected at 2,112 m in MHE on the mountain Doi Phahompok (located approximately 176 km NE of Doi Inthanon). Empidoidea communities at 2,036 –2,105 m on Doi Phahompok share many species with those at 1,639 –2,210 m on Doi Inthanon, although both mountains have many endemic species ( Plant et al. 2020). The MHE habitat is very similar on both mountains so the abundance of this species on Doi Inthanon and rarity on Doi Phahompok is curious.

Although C. abbreviata sp. nov. has been reported in all months of the year, its seasonal abundance phenology is distinctly bimodal with a small peak (16.4% of total abundance) in April–June early in the wet season and a major peak (82.4%) during September–October occurring as the wet season changes to dryer cooler weather ( Fig. 19 View FIGURE 19 ). Because sample size was large in two different years (2006/7 and 2014) when most specimens were collected, and trapping efficiency was similar (similar numbers were caught in individual traps over one year period), it is possible to discern inter-annual variations in phenology. The early wet season peak was somewhat larger in 2014 compared to 2006/7 and the second peak was slightly retarded. Sex ratio (♂: ♀) was 1.23 during the early peak and 0.60 during the late peak when females were more numerous.

Although rather more specimens were caught in Malaise traps set closer to water courses and intermittent streamlines than in traps set well away from any lotic habitat such as on ridge tops, there is no real evidence that C. abbreviata sp. nov. is associated with flowing water. The forest floor of MHE habitats is extremely wet during the rainy season and it is likely that immature stages are associated with such places.