Silba albisquama

Remarks. The following features are noted for the species: Colour black
with rather faint blue-black reflections. Size small; length, exclusive of ovipositor,
about 3.0 mm. Wings distinctly brownish.
; Frons but little narrower at lunule than at anterior ocellus, subshining
brownish black; with a broad, shallow depression between the bases of the orbital
bristles, sides nearly straight. Lunule silvery pollinose, with about 16 coarse
setulae. Face dusted with silvery-grey pollen which becomes gradually thinner
toward the oral margin. Tormae almost as broad as width of frons; about onefourth
as long as wide. With 6-8 oral setulae in a single row, the middle ones
omewhat stronger, but not outstanding and vibrissa-like. Antennae rather short.
Third segment just under twice as long as wide (4.25:2.4); orange-brown at inner
ase. Basal segments orange-brown at apices. Arista wholly brown, with 18 or 19 plumules on each side, width of plumosity about 0.6 as wide as third antennal

segment, or about same width as shortest distance between oral margin and
compound eye.
Mesonotum rather brownish black; shining but not glistening. Scutellum
lightly dusted with greyish brown pollen; with 3 fine marginal setulae
between the scutellar bristles, and 2 very fine apical setulae. Prosternum with
about 8 fine setulae on each side. Mesopleuron with 2 anterodorsal and 3
posterior bristles. Sternopleuron with 2 bristles, the anterior one about half as
long and strong as posterior one.
Wing membrane distinctly brown even to naked eye; more intensely so along
front margin from tip of Sc to apex of wing. Veins brown. Calyptrae dirty
white with concolorous margins and fringes. Legs and tarsi entirely brownish
black. Preapical dorsal bristles not evident on front and hind tibiae, but about
as long as width of tibia on mid tibia.
Dorsum of abdomen shining black with weak blue-black reflections. Terga
l-)-2 brownish pollinose, tergum' 3 very lightly pollmose in middle. Ovipositor
(Fig. 12) rather narrow and evenly tapered to apex. Apical segment slightly
upwardly curved, nearly three times as long as its basal width; preapical ventral
hairs almost as long as basal width of segment.
A male specimen from Friedrich-Wilhelmshafen, New Guinea (Biro 1900),
determined by Kertesz as albisquama belongs to this species. It differs from the
female as follows- Frons much narrower and dull brownish-black. Wings
darker brown, but with same general colour pattern. Calyptrae pale brownish
with dark brown margins and fringes.
Epandrium (Fig. 9) in side view similar in size and shape to that of abstata
iMcAIpine, emulata McAlpine (Figs. 13, 14, 19), and imitata McAlpine (Figs. 15,
16, 17). Ventral margin slightly concave in middle. Apex rather broad and
truncate. Surstylar teeth in two discrete groups, namely, a distal row of four
larger, more closely placed teeth, preceded by a more proximal row of three or
four smaller, more widely spaced teeth (Fig. 8). Cerci extremely small, and
short; separated mesally by a keel-like structure that projects caudally beyond
the apices of the cerci, and bears at its apex, two diverging postero-dorsally
directed setulae (Fig. 8). Aedeagus (Fig. 10) two-segmented as in abstata;
slender apical segment about same length as bulbous basal segment. Hypandrium
(Fig. 11) with a pair of heavily sclerotized, slender, horn-shaped prongs arising
at the inner base of the anterior gonopophyses and projecting meso-ventrally around the base of the aedeagus.