Betasyrphus

Ssymank, Axel, 2010, Review of the species of Betasyrphus Matsumura, 1917 (Diptera: Syrphidae) from Madagascar with description of a new species, Zootaxa 2417, pp. 40-50 : 46-47

Other Betasyrphus species studied

B. stuckenbergi ( Keiser, 1971) : Ƥ: “ Typus [red label, Holotype] \ Manjakatompo, 1700 m \ Madagascar Centre, det Ambatolampy, 11 – 15.XII [19]57, B. Stuckenberg \ Metasyrphus (Betasyrphus) stuckenbergi Keiser [handwritten] \ Muséum Paris, Betasyrphus stuckenbergi, Keiser 1971 ”, approx. 19°20’S, 47°26’E (MNHN); Ƥ: “ Paratypus ” [red label], same locality and labels as holotype, “ Natal Museum Type no. 1582 \ Natal Museum, Piertermaritzburg, South Africa [green label]” (NMSA); Ƥ: Fianarantsoa Prov., Belle Vue, 1.2 km S Ramonafana Nat’l Park entrance, malaise in rainforest 28.XI / 6.XII.2001, 1095 m.A. Harin’Hala, ME Irwin, 21°15.99’ S, 47° 25.21 E, MG 90_05” (CAL) [this is a very dark and shrivelled female, that corresponds in all major morphological characters of Table 1 with the type specimen of B. stuckenbergi . However the face including middle knob is dark yellow to brownish and the frons is blackish].

B. serarius ( Wiedemann, 1830) : type material Ƥ: Mus. Westerm. \ Type [red label]”; [head glued separately on a card on the same pin] (ZMUC); Ƥ: “Mus. Westerm. \ S. serarius Wied. , China, Trentepohl Type [red label] \ Betasyphus serarius Wied. Det. F.C. Thompson 1924 \ Lectoptype Syrphus serarius Wiedemann K.D. Ghorpade des. 1980 \ not type!“ (ZMUC); Both specimen here considered as syntypes. Additional type material in the Wiedemann collection was not available for study.

continued next page Mouth margin On sides partly Side margin yellow completely yellow Side margin dark Side margin yellow brown to black usually dark brown to black

Tables

TABLE 1. Diagnostic characters of Betasyrphus keiseri sp. n., B. serarius (Wiedemann) and B. stuckenbergi (Keiser)

Betasyrphus	B. keiseri sp. n. 3	B. keiseri sp. n. Ƥ	B. stuckenbergi Ƥ	B. serarius 3	B. serarius Ƥ
Origin of examined material	Madagascar	Madagascar	Madagascar	Japan, Korea Australia u.a.	Japan, Korea China (syntypes)
Wing, microtrichia- coverage	Cover high: at least apical ½ of wing including R4+5 fully, microtrichose; Alula completely microtrichose	Cover high: at least apical ½ of wing including R4+5 fully, microtrichose; Alula completely microtrichose	Cover high: at least apical ½ of wing including R4+5 fully, microtrichose; Alula completely microtrichose	Cover high: at least apical ½ of wing including R4+5 fully, microtrichose; Alula completely microtrichose	Cover high: at least apical ½ of wing including R4+5 fully, microtrichose (a small bare patch in type specimen); Alula completely microtrichose
Pterostigma	homogenous yellow to slightly brownish, at most inner border line darker	homogenous yellow to slightly brownish, at most inner border line darker	homogenous yellow	bicoloured: basally distinctly dark – brownish	bicoloured: basally distinctly dark – brownish
Wing colour	slight brownish tinge in the middle part (most males, some males indistinct or hyaline)	slight brownish tinge in the middle part, in about half of females, others homogenous, clear	hyaline, but anterior part of wing with a yellowish tinge	homogenous, hyaline	homogenous, hyaline
Wing, veins	veins mostly brownish to black, especially in apical part of the wing	veins mostly brownish to black, especially in apical part of the wing	veins yellow including costa near pterostigma	veins mostly brownish to black	veins mostly brownish to black
Facial tubercle	yellow no difference to facial ground colour, but sides of face silvery pollinose	yellow no difference to facial ground colour, but sides of face silvery pollinose	yellow no difference to facial ground colour, but sides of face silvery pollinose	black or brownish darkened, differing distinctly from colour of the sides of the face, usually black median vitta reaching mouth margin	black or brownish darkened, differing distinctly from colour of the sides of the face
Long hairs on scutellum	basally yellow, on apical half mainly dark hairs	basally yellow, on apical half mainly dark hairs	mainly yellow	black	black
Hairs on side of the face below antennae	black	black and yellow to brown hairs may be intermixed	completely yellow	black	black