10 BULLETIN 1028, IT. S. DEPARTMENT OF AGRICULTURE. 
cocoon the maggot pupates and casts its larval skin, which is pushed 
back to the posterior end of the cocoon over the previously voided 
material. 
The third-stage maggot (PL I, I) of the summer generation has 
quite a different cycle. After having completed its cocoon, in which 
it is to hibernate, it becomes shorter and stouter, measuring about 
4 mm. in length. It is a pale lemon yellow, and remains quiescent 
until the following spring. About the time when the first gipsy 
moth eggs hatch, the maggot resumes activity, first voiding the ac- 
cumulated waste in the caudal end of the cocoon. Two or three days 
later pupation takes place, and the larval skin is cast and pushed to 
the caudal end of the cocoon, as in the spring generation. 
Pupa. 
The pupal stage lasts from five to nine days. About two days after 
the completion of the cocoon the larval skin is cast. The pupa is 
whitish with long appendages and has a movable abdomen. The 
eyes soon begin to darken, the ocelli are distinguishable, and the 
thoracic and abdominal segments take form. The mouth parts, an- 
tenna?, legs, and recurved ovipositor are plainly seen. In three or 
more days the development is complete. The whole is now dark, 
nearly black. The pupal skin is cast and the adult lifts the cocoon 
cap, having cut around its base, which was left weak by the spinning 
larva. 
Cocoon. 
When the third-stage maggot is about two-thirds of its way out 
of the host, it begins to construct its cocoon. The first few threads 
seem to be attached ventrally to the maggot itself on the last seg- 
ment which is outside of the caterpillar. After making an attach- 
ment at this point the maggot straightens out horizontally, then 
swings back underneath itself again and makes another attachment. 
It continues this process laterally and dorsally, spinning all the 
while and forming loops which it gradually fastens securely in a 
similar manner. As the outer loose cocoon is developed, the maggot 
must break away from the .original attachments and gradually work 
itself entirely free from its host. The maggot reverses its position 
several times during the construction of the cocoon. When com- 
pleted, the cocoon is about 5mm. long and is composed of an outer 
loose covering of fine threads, some of which are attached to the 
host or any object on which it may rest. Just within this is a tough, 
tightly woven envelope, which encases a very fine smooth inner sac 
next to the maggot. The cocoon is slightly flattened on its ventral 
surface and convex laterally and dorsally. The anterior end is 
rather flat. The cap, which is thinner along its base, is at the ante- 
rior end. The posterior end is slightly pointed. It takes the spring- 
