June, 1912.] 
Life- Histories of Syrphidae IV. 
537 
The duration in the pupal stage varied in captivity from 3.5 to 
5.5 days in the case of those taken from persimmon in the spring, 
while in Autumn in specimens from cabbage the duration in the 
pupal stage was in some cases as much as 10 days. 
These pupae are fastened by a viscid substance secreted by the 
anal glands of the larva which, in drying, glues them to various parts 
of the host-plant of the aphids among which they live. They 
attach to the flowers and in the curls of the leaves of persimmon, 
in leaf-axils, or flower spikes of Rumex and on cabbage among the 
outer leaves. In jars they attach to the cloth cover, the glass, or 
to leaves enclosed, apparently with no discretion. 
The body shortens and thickens and the larval skin inflates 
and hardens in the usual manner. Within this puparium profound 
changes take place which culminate in the completely formed 
nymph, which has only to spread its wings and harden, after 
bursting out of the pupa case, to form the perfect fly. 
Adult. 
Description after Williston, Svnop. N. A. Syrph., 9G, 1886. 
(See Fig. 64.) “ cfl 9 . Length, 6 to 7 mm. Face yellow, often 
with a bluish reflection, slightly brownish on the tubercle. Frontal 
triangle yellow; front in the female shining black on the vertex, con- 
tinued as a broad stripe (broadest below) to the antennae; on the 
sides the yellow of the face continues up along the eyes nearly to 
the ocelli. Antennae reddish-brown, blackish on the upper part 
of the third joint. Thorax deep shining green, on the sides with 
a yellow stripe, reaching from the humeri to the suture, where it is 
sharply truncate ; post-alar callosity also yellow. Scutellum wholly 
light yellow, faintly reddish on the disk; pile black. Abdomen 
black, or brown; first segment, except a slender transverse spot on 
each side behind, yellow; second segment with a slender yellow 
anterior fascia, and a broader one in the middle, about a third of 
the width of the segment, straight and but slightly widened at the 
sides; third segment with a broad arcuate band, not quite touching 
the posterior angles on the sides ; fourth segment with two slender 
parallel stripes, leaving a slender black stripe between them, on 
each side a broader, oblique, oval spot, touching, or narrowly 
separated fron the anterior end of the yellow longitudinal stripe, 
and reaching to the posterior angles; fifth segment similar, but 
the side spots less oblique. Legs light yellow; last three joints of 
all the tarsi, the hind tibiae, except the base and a middle ring, and 
a ring on outer part of hind femora, brownish. Wings hyaline, 
veins black. ” 
