16 BULLETIN 918, U. s. DEPARTMENT OE AGRICULTURE. 
sisting of full-fed worms and the younger the winter-feeding brood, 
which were not full-fed at the time of hibernation and continue 
developing slowly till about March. In a later publication {12) 
weighings of resting larvae were made from January to July and it was 
found that the weight constantly fell from February to July. He 
concludes that "the fall in weight does not necessarily demand the 
explanation that the larvae were fasting, but taken along with the 
known fact that many hibernating or aestivating larvae do not feed, it 
lends considerable weight to the probability of the larvae not feeding 
during then resting period." 
A very small proportion of the larvae have not completed their 
growth when the cotton is picked, and these continue feeding for a 
while before making their resting cocoon. In some bolls examined 
November 26, 1918, there was an average of 6.64 fourth-ins tars and 
0.03 third-instars per boll. After the resting cocoon is once spun 
no feeding takes place. If larvae are removed from the seeds in 
which they are resting, other seed will sometimes be hollowed out, 
but the contents are thrown to the outside and no actual feeding 
takes place. It sometimes happens that frost does not come in the 
Laguna till January or February, and it is probable that feeding 
continues longer than usual in such years. 
Duration of the Resting Stage. 
Larvae are capable of passing long periods of time in this quies- 
cent stage. Gough (5) found in seeds of Indian cotton which had 
been imported to Egypt larvae which were over 2 years old. Busck 
(8) in Hawaii compressed cotton seed into small bales and found 
live larvae in them for 18 months. TTillcocks (7) stored a large 
number of bolls picked in November, 1913, in an outdoor cage, and 
moths continued emerging till August 28, 1915, a period of nearly 
2 years. There were 4.4 per cent of the larvae in double seed col- 
lected in November, 1918, still alive on November 20, 1919, when 
work at the station was discontinued. 
Pupation of Resting Larvae. 
When the resting stage has been passed in the lint, single seed, or 
in any place where the larva is curled up in a small, compact cocoon, 
it is necessary to leave this cocoon and prepare more ample quarters 
for pupation. In such cases a lighter, more elongate cocoon is usu- 
ally spun among the fiber or seed, but in some instances in stored 
seed pupae are formed without any protection whatever. 
TVhen the resting stage has been passed in the double seed the con- 
struction of the cocoon between the two seeds makes it elongate 
enough for the larva to pupate successfully and pupation usually 
takes place in situ. In such cases the emergence hole for the moth 
