10 
SOME INSECTS INJURIOUS TO TRUCK CROPS. 
while in the corresponding position on the posterior margin there is 
a paler dusky spot two or three times as large. The head is 3 T ellow, 
and the eyes large and brilliant green with bluish reflections. The 
ovipositor varies from yellow to black. None of these colors is so 
bright in preserved specimens. The length of the body is about 
three-sixteenths of an inch (5 mm.), and the wing expanse is seven- 
sixteenths of an inch (11 mm.). 
The larva, or maggot (fig. 1, h). — The larva, or maggot, is of the usual 
form of the Trypeticlse, measuring about five times as long as wide. 
It is nearly transparent, except in the interior portions, where it is 
yellowish. The contents of the abdominal cavity appear greenish 
through the skin. The length of the body is 7 mm. and the width 
1 .4 mm. The anal segment of the larva as seen from the extreme end 
is illustrated at fig 
ure 1, c. 
The puparium. — 
The larva when full 
grown contracts and 
hardens, forming a 
coarctate pupa or 
puparium (fig. 1, d), 
serving the purpose 
of a cocoon in inclos- 
ing the true pupa. 
In the present spe- 
cies, as with others 
of this group which 
have been studied, 
the form is oval in 
outline, imperfectly 
cylindrical, and ta- 
pering almost equally at both ends. The lower surface is somewhat 
flattened and attached to the leaf by a viscid secretion. The length is 
twice the width and the color pale green when first formed, changing to 
straw color with greater age. The body is composed of 11 strongly 
marked segments. The mouth-parts are retracted within the pupal 
skin, and the cephalic or thoracic appendages (spiracles or trache e) are 
well indicated, forming two arcs, together equivalent to about two- 
thirds of a circle (fig. 1, e). The spiracles are very minute and 
difficult to count, but there are evidently between 21 and 24 on each 
side (fig. 1, g), the probabilities being that there is no constancy as 
regards the number. The length is 4.5 mm. and the width 2.25 mm. 
a The writer fails to see how the Trypetid pupa can be described as ' ' barrel-shaped, ' ' 
'as is done by many writers. 
Fig. 1. The parsnip leaf-miner (A cid ia fratria): a, Fly; b, larva, lateral 
- view; cvanal segments of same; d, puparium; e, cephalic extremity; 
/, anal extremity ; ' g, row of cephalic spiracles; h, anal spiracles, a, b, d, 
'■' Much enlarged, remainder more enlarged. (After Coquillett, except 
b, c, original.) 
