DESCRIPTION AND LIFE HISTORY. 
15 
The head is small, somewhat contracted dorsally, with a row of bris- 
tles on the posterior. margin; eyes black, antennae long, black, semi- 
pallid, usually of 17 joints, this number varying in different specimens 
from 16 to 18; joints rather short, cylindrical, and joined by a very 
short, small filament, each provided with an irregular whorl of fine 
hairs. The thorax has two rows of long backwardly curving bristles 
near the median line, and a patch on either side. The legs are long and 
delicate, with a dense covering of blackish scales dorsally, the basal 
joint of the tarsus very short. The wings appear smoky black from 
scaly covering, but the scales are very narrow, not broad, as those on the 
body and legs. The halteres are yellowish, with broad blackish scales 
covering the outer part, the basal part naked, except a narrow border. 
The abdomen is long, ovate when contracted, but capable of great 
extension for the terminal segments. The ovipositor (fig. 1, a) is com- 
pressed, cylindric, very minutely hairy, with an oval lobe at the 
extremity, which is minutely striate and more densely hairy than the 
basal portion. 
The male is smaller, more slender, and appears darker than the 
female. The antenna' are longer, 
the joints, more distinct, 17 to 19 
in number or 16 to 20 for ex- 
tremes, and connected by a much 
longer filament, and the whorl 
of hairs is much more prominent, 
the hairs longer, and arranged 
in a more perfect verticil. The 
outer claspers (fig. 1, b) are very 
robust and apparently loosely 
connected to the abdomen. The 
basal part is heavy, with numerous strong tubercles and a few scat- 
tered bristles. The distal part is, when at rest, at nearly right angles 
with the basal part, narrower, faintly tuberculate, very minutely hairy. 
and with a strong claw like tooth at end. The inner claspers (fig. 1. c) 
are broad, oval, minutely hairy, the posterior margin with a row of tine 
hairs, and toward the apex three or four blunt teeth. Between the 
claspers is a strong chitinous process, and anterior and dorsal to them 
two pairs of finely haired, slender, finger-like processes directed dor 
sally; anterior to these, and forming the posterior border of the abdom 
inal segment, is a prominent hairy rim, broken at the median line 
dorsally. 
The egg is characterized as about one half millimeter long, cylindric, 
roundingly pointed at the ends, glossy translucent, slightly reddish in 
color, and becoming deeper red with development. 
The larva has usually been described without reference to distinct 
stages, but Marchal (71) has defined three forms, the first ol' which, just 
issued from the egg, is capable of locomotion and travels from the point 
«- 6 c 
Fig. 1. — Cecidomyia destructor: a, ovipositor of fe- 
male; b, outer claspers of male: c, inner claspers of 
male (origiual). 
