Criorhina rostrata Li, Huo & Li, 2020

Li, Hu, Huo, Ke-Ke & Li, Bao-Guo, 2020, A new species of the flower fly genus Criorhina Meigen (Diptera: Syrphidae) from mainland China, Zootaxa 4803 (1), pp. 169-176 : 170-172

Criorhina rostrata Li, Huo & Li sp. nov.

( Figs 1–17 )

Examined material. HOLOTYPE. ♂, CHINA: Henan Province, Luoyang City, Luanchuan County, Laojunshan , 10–15.vi.2016, collected by Pu Cheng. PARATYPES. 18 ♂ 5 ♀, same data as the holotype .

Body length. Males, 13.5–15.5 mm (n=19); females, 14.0–16.0 mm (n=5).

Description. MALE. Head ( Figs 1–5 , 9–10, 14 ). Face ( Fig. 4 ) silver pollinose, except black on distal part in frontal view and lateral parts in side view, with ventral part strongly produced downwards; occiput with long, dense, yellowish setae around margin; vertex dark, dark pollinose, with sparse, long, yellowish to dark setae; ocelli brown; eyes ( Figs 3–4 ) black, bare; frontal triangle pale-yellowish pollinose ( Fig. 10 ), except shiny black on central region; antenna ( Figs 4–5 ) with brown scape and pedicel, each with fine setae on distal half and several stout setae on dorso-apical margins, basoflagellomere ( Figs 5 , 9 ) yellowish, short, slightly wider than long, with dense, fine setae on surface, and small basomedial sensory pit on inner side, arista yellow on basal half and black on apical half, bare; gena black and bare; proboscis ( Figs 2 , 14 ) remarkably elongate, of equal length as body, darker brown. Thorax ( Figs 1–2, 7 , 11–13 ). Ground color black; with dense long yellow pile on surfaces of humeri and mesonotum; pleuron ( Fig. 2 ) black, slightly gray pollinose, sulci sometimes orange. Scutum ( Fig. 1 ) with a narrow medial and a pair of two broad pale longitudinal pollinose vittae before transverse suture; posterior anepisternum strongly convex and densely covered by long yellowish setae; anepimeron with slightly shorter and more-slender yellowish gray setae; katepimeron with long yellowish setae; katepisternum sparsely pale yellowish pilose. Scutellum ( Fig. 1 ) slightly dark brown pollinose. Legs. Coxae, trochanters, femora, fourth and fifth tarsomeres of all legs black, tibiae dark yellowish but dark brown medially, claws yellow with dark brown apical halves ( Fig. 11 ) on ventral surface, pulvillus ( Fig. 12 ) with specialized setae with inflated apices; coxae and femora ( Fig. 7 ) with long yellowish-white pile at ventral margins, metafemur ( Fig. 7 ) clearly enlarged centrally and strongly arc-shaped, metatibia ( Fig. 7 ) somewhat twisty and flattened. Wings ( Figs 1–2 ). Hyaline, with slight brown tinge and dark brown transverse band at frontal half of midline, venation prominent and dark brown; intersection of vein R 1 with vein C ( Fig. 25 ) narrow, and setae on the antero-ventral half of vein C before crossvein h absent ( Fig. 26 ), distance between apices of veins R 1 and R 2+3 slightly longer than that of R 2+3 and R 4+5 +M 1; wing surface generally covered with tightly placed microtrichia ( Fig. 13 ) except basal halves of 1 st and 2 nd basal cells (cells R and M) where they are sparse or absent. Abdomen ( Fig. 6 ). Tapered to round apex, black, covered in long yellow setae. 1 st tergum slightly gray pollinose, with yellow anterolateral corners; 2 nd tergum ( Fig. 6 ) with two large, widely separated, gray pollinose maculae, 3 rd and 4 th terga ( Fig. 6 ) with similar but smaller pollinose regions. Male terminalia ( Figs 15–17 ). Cercus ( Fig. 16 ) weakly developed, slender and oblong, surface covered in pili-like setae; surstylus ( Figs 15–16 ) large, with clearly triangular process pointed medially and long setae on dorsal margins. Hypandrium ( Figs 16–17 ) with well sclerotized and tubular hypandrial theca, with frontal margin truncate, basal half clearly bulbous, inflated and round in ventral aspect, medial area with a pair of triangular prominences, and sheet processes, apex elongate, bilobate, each produced into a stout process twisted ventrally. Aedeagus ( Fig. 17 ) clearly short, stout, and bent ventrally, aedeagal apodeme long, posterior end slightly inflated.

FEMALE. Body coloration pattern and appearance similar to male except the wholly black and bare face ( Fig. 8 ), metafemur less inflated compared to that of male, and slightly larger in body size.

Etymology. The specific epithet of the new species name, rostrata , is derived from the Latin word “ rostratus ”, meaning the species has a conspicuously long proboscis nearly as long as the entire body.

Differential diagnosis. The body appearance and color pattern of the new species is somewhat similar to Criorhina brevipila Loew, 1871 , but it is distinguishable from the latter and other members of Criorhina by the follow- ing features: bumblebee mimic; a long proboscis; an silver pollinose face with black apex in front view in male but shiny black and bare in female; long yellow pile on thorax and abdomen; strongly developed, arc-shaped metafemur and twisted metatibia; the hypandrium medially with a pair of triangular prominences and lamellar processes, and also the stout aedeagus.

Figures

FIGURES 1–8. Criorhina rostrata sp. nov. 1–7. Male; 8. Female. 1. Habitus, dorsal view; 2. Habitus, lateral view; 3. Head, lateral view; 4, 8. Head, frontal view; 5. Antenna, dorso-frontal view; 6. Abdomen, dorsal view; 7. Metafemur and metatibia, antero-lateral view. Scale bars=5.0 mm (1–2), 2.0 mm (3–4, 6–8), 1.0 mm (5).

FIGURES 9–14. SEM photographs of Criorhina rostrata sp. nov. 9. Microsetae on surface of basoflagellomere; 10. Pollinosity on frontal triangle; 11. Microsetae on ventral surface of claw; 12. Specialized setae on pulvillus; 13. Microtrichia on surface of wing; 14. Middle part of proboscis.

FIGURES 15–17. Criorhina rostrata sp. nov. 15. Male genitalia, ventral view; 16. Male genitalia, dorsal view; 17. Hypandrium, lateral view. Scale bars=0.5 mm (15–16), 0.2 mm (17).

FIGURES 25–26. Wing of Criorhina rostrata sp. nov. 25. Narrow intersection of vein R1 with vein C; 26. Absence of setae on anterior ventral half of vein C before crossvein h. Scale bars=3 mm (25), 0.5 mm (26).