197 
so as to make the width of the marginal cell just equal to the distance 
between the apex of the stigma and that of the stigmal vein. Hind 
wings with a dusky costal vitta extending to the tip of the wing. 
Remaining veins of both wings slender and pale dusky. Length 1.27 
mm; width of abdomen 0.5mm; length of wing 1.77—2.03mm; to tips 
of wings 2.28—2.54mm. 
May—July; St. Louis, Mo. 
On the under side of leaves of Quercus rubra. 
Very closely related to C. bella (Walsh), with which it has been 
hitherto confounded. 
Callipterus uella. Walsh. 
Aphis bella , Walsh, Genera of N. Am. Aphidte Phil. Ent. Soc. 1862. 
In some specimens, a series of capitate hairs can be detected on the 
margin of the abdomen of the unborn larvae, which can be seen 
through the sides of the abdomen of the viviparous females. The 
young of some individuals seem to lack these hairs. A similar case 
has been noticed by Professsor Riley in Schizoneurafungicolaf (Walsh) 
in which the very young larvae occur with and without capitate hairs. 
These hairs, on being very highly magnified, appear to be hollow, 
with a funnel-shaped opening at the apex. 
Length 2.54—3.04mm; of wings 3.55—3.81mm, to tip of wings 4.06 
—4.31mm. 
CALLrPTERUS ASCLEPIADIS. U. Sp.. 
Winged form —General color yellow. Antennae filiform, mounted on 
very short tubercles, as long as, or a little longer than, the body; apical 
joint much longer than the preceding. Nectaries yellowish, short. 
Apterous individuals —With capitate hairs, which disappear when the 
insect acquires wings; abdomen somewhat tubercular. 
Winged individuals —Wings blotched with dusky or dusky brown; 
an irregular broad band running from the apex of the second discoidal 
to the apex of the upper forklet, and another running from the apex 
of the first discoidal towards the base of the cubitus, but becoming 
obsolete before reaching that point. Stigma short, abruptly tapered at 
apex. Distance between the tips of the first and second discoidals 
one-half that between the tip of the second discoidal and the lower 
cubital branch. Distance between the base of the cubitus and the base 
of the stigmal vein nearly equal to the distance between the apices of 
the lower forklet and the lower branch of the cubitus. Length 1.27— 
1.52mm; to tip of wings 2.54mm. 
May—August. 
Very common at St. Louis on Asclepias cornuti and A. obtusifolia. 
This is the first species belonging to this genus which has been found 
on a herbaceous plant. 
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