Sericomyia khamensis Thompson & Xie

Xie, Hongyan, Cunningham, Saul A., Yeates, David K. & Thompson, F. Christian, 2014, A new sericomyiine flower fly from China (Diptera: Syrphidae), Zootaxa 3860 (1), pp. 81-86 : 83-85

Sericomyia khamensis Thompson & Xie , sp. nov.

Type material. Holotype male from CHINA, Sichuan, Xiangcheng, site 9, 30 June 2006, J. Ash and HongYan Xie. Paratypes: same data as holotype (2 males, 2 females); Yunnan, Zhongdian, site 5, 29 May 2006, HongYan Xie (1 male); [same locality], 29 June 2006, J. Ash & HongYan Xie (1 female); [same locality], site 23, 12 July 2006, HongYan Xie & T. Fitz-Simon (1 female). Holotype deposited in China Agriculture College, Beijing ( BAC), paratypes in ANIC and USNM.

Etymology. The epithet is an adjective based on the historic name of the region, Kham (eastern Tibet), where the species was found.

Length (in mm). Body: males (n = 6): 8.4–9.9, females (n = 2): 9.7–11.1 (overall average 9.60). Wing: males 7.8–9.3, females 8.8–10.0 (overall average 8.75).

Description. Male (fig. 1): Head. Black except face yellow laterally; face sparsely white pollinose laterally, shiny medially, bare; gena shiny, white pilose; frontal triangle gray pollinose, black pilose; vertical triangle gray pollinose, black pilose except for a few yellow pili in middle of ocellar triangle; broadly dichoptic; occiput sparsely gray pollinose except denser and white near eye, white pilose; antenna black, black pilose. Thorax. Black; postpronotum sparsely gray pollinose, white pilose; scutum black pollinose, black pilose except notopleuron and postalar callus white pilose; scutellum sparsely gray pollinose, white pilose; pleuron sparsely gray pollinose, white pilose; calypter white. Wing: microtrichose, hyaline except for black on basal 1/2 (costal cell to cell dm black) and medially from costal margin across crossvein r–m to discal cell; tegula and basicosta black. Legs: Black except reddish apical 1/5 of metatibia and basal 3 metatarsomeres; coxa and trochanters black pilose; pro- and mesofemora black pilose except white pilose posteriorly; metafemur black pilose; tibiae yellow pilose; tarsi pale pilose on basal 3 tarsomeres, black pilose on apical 2 tarsomeres. Abdomen. First tergum black, black pollinose, black pilose; 2nd tergum black, shiny except black pollinose on basomedial 1/3, black pilose except with long white pile on lateral 1/4; 3rd tergum black except apical margin brownish, shiny, black pilose; 4th tergum red, shiny, red pilose; genitalia black, red pilose; 1st sternum black, gray pollinose, white pilose; 2nd and 3rd terga black, shiny, white pilose; 4th tergum black except reddish brown apically and laterally, shiny, red pilose. Male genitalia as figured (figs 2–5), of typical sericomyiine structure with asymmetric surstyles, with right surstyle quadrate with dorsal and ventral lobes, with left surstyle with only elongate apically curved dorsal lobe; paramere (superior lobe) serrate apically.

Female: Similar except for normal sexual dimorphism, 5th tergum orange, red pilose; genitalia black; cercus orange.

Remarks. All types were collected as part of a study of the pollination of the yellow poppy ( Meconopsis integrifolia [ Papaveraceae ] (Cunningham et al., in prep.). This yellow flowering poppy is locally abundant in alpine grasslands from 2,750 to 5,500 m (9,000 to 18,000 feet), ranging from the dry regions of the Tibetan Plateau (250 mm annual rainfall) to the wetter mountainous regions of Yunnan and Sichuan (14,000 mm annual rainfall) that experience high rainfall during the flowering season. Flowers in the drier northwestern region were generally erect and open, and here we (Xie & Cunningham) did not observe S. khamensis . The petals in the wetter southeastern regions were often loosely enclosed the pistils and stamens until after pollen dehiscence, and in many plants flowers drooped so the petals gave shelter from rain. Temperatures inside flowers were up to 2.5°C above air temperature. Flies of several species including S. khamensis were frequently found within flowers and often had large pollen loads.

In the definitive treatments of the flies of China ( Huang & Cheng 2012: 612–616), the only sericomyiine flower flies included are Pararctophila oberthuri (Hervé-Bazin) , Pseudovolucella mimica Shiraki , Sericomyia lappona (Linnaeus) and S. completa Curran (the earlier treatment by Yang & Cheng (1998: 200) only lists P. oberthuri ). Sericomyia khamensis is readily distinguished from all of these species by the generic characters of Pararctophila and Pseudovolucella and from the Sericomyia species by being a Bombus mimic and its smaller size (10 mm or less, versus 14 mm or greater). Earlier Stackelberg (1927) provided a revision of all the Palaearctic species.