Sphegina (Asiosphegina) forficata, Hippa, Heikki, Steenis, Jeroen Van & Mutin, Valeri A., 2015

Hippa, Heikki, Steenis, Jeroen Van & Mutin, Valeri A., 2015, The genus Sphegina Meigen (Diptera, Syrphidae) in a biodiversity hotspot: the thirty-six sympatric species in Kambaiti, Myanmar, Zootaxa 3954 (1), pp. 1-67 : 33-34

Sphegina (Asiosphegina) forficata sp. n.

Figs 18 A–C

MALE. Body length 5.0– 6.5 mm, wing length 4.7–5.8 mm. Head. Face strongly concave, moderately projected antero-ventrally; frontal prominence moderately developed (somewhat similar to Figs 1J, K). Width of vertex at anterior ocellus:width of head 1:3.5; depth of the occipital fossa less than 1/4 of the width of an eye in dorsal view [1:3.5]. Width of face:width of head 1:3.5. Face ventrally yellow, rather shiny, dorsally brownish, pale pollinose. Gena shiny yellow. Frons and vertex shiny dark brown; frons with a pale-pollinose medially interrupted band just behind the frontal prominence; the pile short, erect and pale. Occiput shiny black. Antenna brownish; basoflagellomere elongated, ratio of length:width 1:0.7, baso-ventrally yellow; arista pilose. Thorax. Colour dull reddish or brownish, anepimeron, postero-dorsal part of katepisternum, metasternum and metaepisternum yellow; scutum with a black fascia medially on the anterior 1/2, medially divided by a narrow fascia of pale pollinosity, and a sublateral black fascia which is interrupted at the transverse suture; the pile of scutum short, adpressed and reddish; scutellum semicircular, shiny, brownish, ratio of length:width 1.8–4.5, pile similar to the posterior part of scutum, a pair of thin, not longer than scutellum, widely separated, pale setae at apical margin. Wing. Hyalinous, stigma yellow, infuscated along transversal veins. Legs. Pro- and mesoleg yellow, tarsomeres 4 and 5 brownish, sometimes tarsomere 3 brownish entirely or apically. Metaleg: coxa brownish; trochanter simple, brownish; femur yellow with a broad ventrally interrupted diffuse brown annulus at the middle or extensively brown with only the basal 1/3 yellow, basal part curved ventrally and with numerous black setae; tibia without apico-ventral tooth, brown, the basal 1/4 and an annulus on apical 1/2 yellow; tarsus black. Abdomen. Length ratio of tergites I, II, III and IV 1:3.5:2.3:1.5. Tergites shiny brown to black; tergite III yellow on the anterior 1/4; tergite IV yellow on anterior 1/6 or with a semi-round anterior yellowish macula; the pile of tergites adpressed and pale, becoming longer towards the lateral margin; tergite I with 2, usually black, strong setae at lateral margin; sternite IV ( Fig. 18 C) almost symmetrical, the pile pale; sternites VI–VIII simple, brown, the pile pale. Genitalia, Figs 18 A, B. Note the symmetrical surstyli and superior lobes and the long curved aedeagal lobe as well as the long curved postero-dorsal part of aedeagus. FEMALE. Length of body 4.8–6.0 mm, wing length 4.5–6.1 mm. Similar to male except for the normal sexual dimorphism. Thorax black with submedial vittae of scutum, postpronotum, anepimeron, postero-dorsal part of katepisternum and postalar callus brownish or reddish. Pro- and mesoleg yellow with tarsomeres 4 and 5 more or less darker than basal tarsomeres. Metafemur usually entirely yellow or yellow on the basal 1/3, followed by a brownish annulus and a reddish apical 1/ 2 in some females; metatibia brownish with yellow base and apical yellow annulus. Length ratio of tergites I, II, III and IV 1:2.9:2.5:1.8, ratio of length:width of tergites III and IV 1:1.3 and 1:1.7; tergites I–III shiny black except sometimes tergites II and III with yellow medial semi-round or oval macula at anterior margin, tergites IV–VI yellow, tergite IV obscured antero-laterally. Sternite IV brownish, trapezoid, ratio of width at anterior margin:length 1:4.8, with pale pile, posterior margin with triangular excision and clearly broader than anterior margin of sternite V; sternite V semirectangular, longer than wide, with long pale pile posteriorly.

Type material. HOLOTYPE. ♂, N.E. Burma, Kambaiti, 2000 m, 18.v.1934, R. Malaise ( SMNH). PARATYPES. 2♂ and 1♀ with same data as holotype except 23.iv. ( SMNH, NBC); 1♂ with same data except 11.v. ( SMNH); 1♀ with same data except 15.v. ( SMNH); 1♀ with same data except 18.v. ( SMNH); 1♀ with same data except 24.v. ( SMNH); 2♀ with same data except 25.v. ( SMNH, NBC); 1♂ with same data except 7.vi. ( SMNH); 1♂ with same data except 9.vi. ( SMNH); 1♂ with same data except 7000 ft., 30.iv. ( SMNH); 3♂ with same data except 7000 ft., 2.v. ( BMNH, NBC); 1♂ with same data except 7000 ft., 5.v. ( BMNH); 1♂ with same data except 7000 ft., 12.v. ( SMNH); 7♂ and 3♀ with same data except 7000 ft., 14.v. ( SMNH, NBC); 2♂ and 1♀ with same data except 7000 ft., 15.v. ( SMNH, NBC); 1♂ with same data except 7000 ft., 20.v. ( BMNH); 1♂ with same data except 7000 ft., 23.v. ( SMNH); 1♂ with same data except 7000 ft., 6.vi. ( SMNH); 2♀ with same data except 7000 ft., 7.vi. ( BMNH, NBC); 1♂ with same data except 7000 ft., 9.vi. ( SMNH); 1♀ with same data except 7000 ft., 11.vi. ( SMNH); 1♀ with same data except 8000 ft., 28.iv. ( SMNH); 2♂ with same data except 8000 ft., 12.v. ( SMNH, NBC).

Etymology. The name is Latin, forficata , forked, referring to the forked appearance of aedeagus.

Discussion. Sphegina forficata is very similar to S. crucivena . For more discussion, see under the latter. The male genitalia in both these species recall S. nasuta by the long, narrow and curved aedeagal lobe.

Figures

FIGURE 18. Sphegina (Asiosphegina) forficata sp. n. (holotype). A. Genitalia, lateral view. B. Left surstylus, lateral view. C. Posterior part of sternite IV, ventral view. Scale 0.5 mm.