Silba inubiwa
With only one strong katepisternal
seta and relatively short hairing on the arista this
species could easily be mistaken for a species of Lonchaea.
However the distinctive row of strong prensisetae
on the inner margin of the surstylus clearly shows that
this is a species of Silba.
Description. Male. Head: Eyes bare. Frons approximately
half width of eye, matt black frontal and interfrontal
setulae no more than one fifth length of orbital
seta. Orbital plate shining black, bare. Frons slightly
silvered bearing 8–10 setulae. Face and parafacial dull
black. Anterior genal setulae in single row of 4, becoming
slightly stronger basally, slightly separated from
other setulae on genae. Antennae entirely black, 1st
flagellomere, 1.5 times as long as deep, arista with short
hairing, maximum width approximately half depth of
1st flagellomere.
Anepisternum with 3 strong setae anteriorly and 4
posteriorly. Proepimeron with one seta, one stigmatical
seta. Katepisternum with one strong seta at mid point
near dorsal margin, no setulae posterior to it, a few
scattered setulae on anterior portion of the sclerite.
Scutellum shining black, margin between lateral and
apical setae with four short setulae on left and two on
right, one between apical setae. Calypteres slightly
greyish with short, pale fringe of uniform length. Wings
hyaline with light brown veins. Wing length 3.5 mm.
Legs entirely black including ventral fringe of fore and
hind tarsomeres, hind femur slightly bent.
Male genitalia (Figs 1–4): Epandrium in lateral view
rounded, slightly higher than wide, with semicircular
excavation anterodorsally; on ventral margin bearing
marginal row of strong setae. Cercus rather short and
roughly rectangular, about one third as high as epandrium,
not heavily chitinized, bearing rows of short
setulae along the posterior and ventral margins. Surstylus
coalescent with epandrium, posteriorly on inner
surface with 10 black prensisetae, 9 in single row with
one lying more anteriorly, posterior seven prensisetae
largest and set in close approximation, posterior prensisetae
situated along margin of surstyli but anteriorly
gradually becoming more distant from margin, more
widely separated, smaller and thinner. Outer margin of
surstylus with 7–8 long spine-like setulae in regular row Ventral margin of surstyli projecting only slightly
beyond shell of epandrium. Prensisetae on basal plate of
surstyli not evident in lateral view. One strong seta
accompanied by a few fine setulae located below base
of each cercus. Phallus simple, J-shaped tube without
ornamentation, apical portion twice as long as basal.
Female terminalia: In lateral view apical segment of
aculeus blade-like, in dorsal view diamond shaped with
basal half embedded in rods of aculeus, apical segment
with a few pairs of short setulae laterally, pre-apical pair
longer than others, approximately 75% width of apical
segment