The genus Sphegina Meigen (Diptera, Syrphidae) in a biodiversity hotspot: the thirty-six sympatric species in Kambaiti, Myanmar
Author
Hippa, Heikki
Author
Steenis, Jeroen Van
Author
Mutin, Valeri A.
text
Zootaxa
2015
3954
1
1
67
journal article
10.11646/zootaxa.3954.1.1
44878647-9450-4895-ad32-d1fc79eb30ea
1175-5326
288397
AA3DB71F-AD9A-4205-889B-FB212E367A37
Sphegina (Asiosphegina) forceps
sp. n.
Figs 3
B, 25A–C
MALE.
Body length 5.0–
5.5 mm
, wing length
4.2–4.6 mm
.
Head.
Face strongly concave and strongly projected antero-ventrally; frontal prominence moderately developed (somewhat similar to Figs 1J, L). Width of vertex at anterior ocellus:width of head 1:4.1; depth of occipital fossa 1/5 of the width of an eye in dorsal view. Width of face:width of head 1:3.9. Face with the ventral 1/2 yellow, dorsal 1/2 black and both densely pale pollinose. Gena shiny yellow, usually darkened posteriorly. Frons and vertex shiny black; lunula shiny brown; frons with a narrow pale-pollinose band just posterior to the frontal prominence; the pile very short, erect and pale. Frontal prominence with rather deep medial depression. Occiput dull black. Antenna brownish; basoflagellomere elongated [length:width 1:2.5]; arista almost bare basally and distinctly pilose apically.
Thorax.
Colour black, postpronotum yellow, postalar callus brown, overall slightly pale pollinose (in
2 specimens
pleura more or less extensively yellow); scutum mainly black with yellow sides, with the pile adpressed, golden; scutellum shiny black, rather semitriangular, the pile short, pale and adpressed, with a pair of thin, long, yellow setae at apical margin.
Wing.
Hyaline, stigma yellow.
Legs.
Pro- and mesoleg yellow, tarsomeres 4 and 5 obscure dark. Metaleg (
Fig. 3
B) coxa brownish; trochanter simple, yellow; femur yellowish to pale yellowish-brown, the apical 1/3 blackish, the submedial darker annulus brownish; tibia without apico-ventral tooth, brown, on apical 1/4 black, at extreme base yellow and the annulus (on the apical 1/2) pale yellowish; tarsus black entirely.
Abdomen.
Length ratio of tergites I, II,
III and IV 1
:3.0:1.6:1.4. Colour of tergites shiny black, tergite III reddish or yellow on anterior 1/3–1/6, tergite IV with a narrow transverse yellowish macula at anterior margin; the pile reddish, short and adpressed, becoming longer laterally; tergite I with an oblique row of 3–4 thin, long, pale setae laterally; sternite IV (
Fig. 25
C) unusually symmetrical, black, the pile and the stronger postero-medial setae reddish or brown; sternite VI simple, black, the pile dark and short; sternites VII and VIII black, the pile dark.
Genitalia.
Figs 25
A, B. Note the symmetrical surstyli, the unusual cercus with a long posterior prong which is apically sclerotized, as well as the unusual aedeagus. The superior lobes are symmetrical.
FEMALE.
Unknown.
Type
material.
HOLOTYPE
. ♂, N.E.
Burma
, Kambaiti,
2000 m
,
4.vi.1934
, R.
Malaise
(
SMNH
, strongly damaged).
PARATYPES
.
1♂
with same data as
holotype
except
4.vi.
(
NBC
);
1♂
with same data except
7000 ft
,
12.v.
(
SMNH
).
Etymology.
The name is Latin,
forceps
, pincers, referring to the pincer-like cerci.
Discussion.
Sphegina forceps
is not especially similar to any other species. It may recall such species as
S. forficata
,
S. nasuta
and
S. simplex
but is at once distinguished by having an oblique row of slightly strengthened setae postero-laterally on sternite I instead of two or three strong setae in a longitudinal row at the actual lateral margin of the tergite. The male genitalia are quite unique: the cerci which are posteriorly elongated as a curved apically sclerotized lobe and the aedeagus with posteriorly directed ejaculatory hood, ejaculatory tube and aedeagal lobes are much unlike any other species.