366 NEW YORK STATE MUSEUM 
Female. Length 2.5mm to 3mm. Head uniform slate-blue, 
verging to greenish, or cerulean blue in some lights, clothed 
with silvery pubescence, which becomes longer behind the eyes; 
parts below the antennae and trophi more densely pubescent, 
producing the effect of a white face; eyes with a metallic coppery 
luster; antennae black with very dense white pubescence; no 
bristles on basal two joints, which are but very slightly tinged 
with red; joint 1 shortest; joints 2, 3, and 11, subequal in length; 
joint 3 widest; joints 4 to 9 subequal in length; joint 10 but 
slightly shorter than joint 11, which is fusiform; joints 3 to 11 
gradually decreasing in width. Maxillary palpi as long as 
antennae, blackish, with long, whitish bristles. Thorax slate- 
blue, with less dense, silvery white pubescence; markings quite 
distinct, producing the effect of a sculpture, and consisting of 
three black longitudinal lines, the median narrow, widening a 
little at the apex, and the outer one curving inward at base, and 
outward at apex, sometimes reaching to base of patagium, 
which appears whitish on account of the dense pubescence; on 
the lateral edges of prothorax are fine black sutures; underside 
uniform slate-blue, with sparse pubescence; space around the 
large stigma almost white. Halteres white, very faintly tinged 
with red. Abdomen nine jointed, joints subequal in length, — 
except the last two, which decrease; markings entirely differ- 
ent from those of S. pecuarum, formed by velvety black, 
dark blue and bluish white, almost silvery, colors; the dark blue 
appears on dorsal surface of the last five segments, spreading 
from a roundish median spot, on 5 to the immaculate blue of the 
last two segments; segments 2, 3, and 4 have each a black cross- 
bar, and 5, 6, and 7, two narrow, black submedian stripes, which 
disappear almost entirely on 7; the bluish white forms an outer 
edge to all the black and extends over the whole lower surface 
of the abdomen, with the exception of more or less well marked 
black cross lines in middle of each segment; a bluish white or 
silvery pubescence covers the entire abdomen, but is very sparse 
on the dorsal parts. Legs brownish black; tarsi almost black, 
and more or less densely covered with white hairs. Wings, sub- 
hyaline. Veins bluish white, base ferruginous. Described from 
many bred and captured specimens. 
Male. Length 1.5mm to 2mm. Very different in appearance 
from female. Eyes confluent, very large, brilliant coppery; a 
very marked difference in the size of the facets, those on upper 
surface being very large and metallic copper, those below and 
surrounding trophi becoming suddenly small, black, with bronze 
reflections; trophi reddish black, dwarfed; antennae black, with 
light, yellowish brown pubescence in front. Thorax above in- 
Le 
