47 
sibility that the injury in Michigan was done by the seed-chalcid rather 
than by the seed-midge. 
Alfalfa is not yet known to be a food plant of this insect. 
Descriptions. — The egg is barely visible to the naked eye. It is 
elliptico-cylindrical in form, at most 0.3 mm. long and 0.075 mm. broad, 
with the shell smooth and transparent. The color is at first a uniform 
watery yellow, but soon an internal orange spot appears, and finally 
the egg becomes orange thruout. 
The larva ( I'l. II., Fig. 1 ) is a footless maggot, orange-red, pink, or 
almost white, 2.3 mm. long and one third as broad, when full grown, 
with the surface of the skin minutely granulate. It has thirteen seg- 
ments behind the head, and, like other cecidomyiid larvae, bears nine 
pairs of respiratory tubercles, situated respectively on segment 2 and 
segments 5 to 12 inclusive. All these tubercles are lateral in position 
excepting the first and the last pairs, which are dorsal and posterior on 
their respective segments. A peculiar organ known as the sternal 
spatula may be detected lying against the ventral face of segment 2, 
and the form of this organ ( PI. II., Fig. 2), while subject to some varia- 
tion, is sufficiently characteristic to distinguish this larva from that of 
the clover leaf-midge, the only other insect with which it is likely to 
be confused. 
The cocoon, made by the larva, is oval in form, 2 mm. long, and 
composed of silken threads. It is difficult to find out-of-doors owing 
to its being covered with particles of dirt. The pupa, described in 
some detail by Comstock, is pale orange, with brown eyes, a pair of 
short conical tubercles on the front of the head, and a rather long horn 
near the base of each wing; the antennal sheaths of the cast pupal 
skin curve outward like the handles of an urn. 
The appearance of the female midge is well shown in Figure 3, 
Plate II. When on the wing, she is nothing but a filmy speck, that 
easily eludes the vision. After alighting, her red abdomen and long 
threadlike legs catch the eye. Under the microscope, the head is seen 
to be black, and the antennae yellowish red, with sixteen — or even sev- 
enteen — sessile segments. The sides of the thorax are reddish brown ; 
above, most of the thorax is black, but two small posterior lobes are 
brownish red ; the halteres are reddish yellow. The wings are trans- 
parent, closely set with short, curved, dusky hairs, and strongly fringed 
posteriorly with long paler hairs. Legs slender, reddish brown, the 
segments becoming darker distally. The abdominal segments 1 to 6 
are salmon-red above, mixed with yellowish beneath ; dorsally each of 
these segments is banded with black scalelike hairs, which rub off 
easily. Segments 7 to 10 of the abdomen form the pale yellow 
ovipositor. The insect, with ovipositor retracted, is 1.8 to 2 mm. in 
length, and with the ovipositor extruded, 6.2 mm. The antennae are 
0.8 mm. in length. 
The male resembles the female, but bears a pair of conspicuous 
clasping organs at the end of the abdomen and has but fifteen antennal 
segments, all but the first two of which are pediceled. 
