CHRYSANTHEMUM MIDGE. 11 
the yolk then takes place, an equal’ portion being present in each seg- 
ment. At this stage the pigment takes up a posterior position. 
Finally the complete outline of the larva is visible through the shell. 
At this stage the darker head and mouth parts can be seen, and the 
previous yolk material appears as a chainlike formation which ex- 
tends from the anterior to the posterior end throughout the entire 
inner or central portion of the body. Distinct segmentation is now 
clearly visible. 
Hatching.—Borden observed the larva when hatching to break 
from the eggshell by a small cap at one end. Complete development 
of the larva and pupa takes place within the gall. 
LARVAL AND PUPAL STAGES. 
The larva or maggot upon hatching moves about on the surface 
among the plant hairs for a period of from 1 to 3 days, preparatory 
to boring into the tissue. It varies in color from a transparent white 
to pale orange when seen with the aid of a binocular just after boring 
beneath the epidermis. On February 2, 1918, H. F. Dietz observed 
larve, which hatched from eggs laid four days previously, boring 
into tissue. (10 eyepiece, 24 mm. objective, binocular.) The 
observations were as follows: One larva which was found half buried 
in the tissues of the stem was timed until it disappeared. It required 
12 minutes for complete disappearance. During this period the 
larva moved back and forth with an irregular spiral movement, 
about 30 seconds being necessary for one complete movement back 
and forth. Several larvee were then observed beginning to bury 
themselves, but the operation was interrupted and discontinued, the 
interruption being caused by another larva which was slowly crawling 
about in search of a suitable place to “dig in.’’ One of these larvee 
was observed crawling slowly about for approximately 3 minutes. 
The bright red pigment of the posterior third of the body is very 
characteristic at this particular stage. 
As a result of the larva boring into the tissue, an irritation is pro- 
duced which results in the production of swellings or galls on the plant 
containing the developing larve and pupe. 
No molts have been observed from the time of hatching to the time 
at which the larva is seen entering the tissue. The larva lies bathed 
in a fluid within the gall. The fully developed larva is of an orange 
color. 
The female pupa is usually orange colored with the head, thorax, 
legs, and wing pads nearly black, while the male may be of a lighter 
or straw color. Formation of the pupa takes place about two weeks 
from the time the egg is hatched. It is white at first with only a 
slight brown tinge about the head, but later the head, thorax, wing- — 
