April, ’18] 
BALLOU: PINK BOLLWORM 
239 
water with a film of kerosene on it. The surface of the water was 
about 3 feet above the floor level. 
Table Giving Numbers op Moths Caught in Light Trap in Large Cotton Seed Store at Alexandria in 1917 
Date 
Moths 
Date 
Moths 
June 
21 
26 
July 
13 
97 
June 
22 
20 
July 
14 
107 
June 
23 
15 
July 
15 
236 
June 
25 
57 
July 
16 
June 
26 
32 
July 
17 
137 
June 
27 
26 
July 
18 
180 
June 
28 
20 
July 
19 
180 
June 
29 
18 
July 
20 
June 
30 
38 
July 
21 
800 
July 
1\ 
65 
July 
22 
July 
2/ 
July 
23 
July 
3 
20 
July 
24 
80 
July 
4 
26 
July 
25 
60 
July 
5 
28 
July 
26 
40 
July 
6 
28 
July 
27 
40 
July 
s\ 
52 
July 
28 
27 
July 
9/ 
July 
29\ 
20 
July 
10 
68 
July 
30 / 
July 
11 
72 
July 
31 
12 
July 
12 
80 
August 
1 
5 
The seed store at Alexandria in which the light trap catches were 
made, as recorded in the preceding table, was emptied of seed on Aug¬ 
ust 4. New seed from Upper Egypt and the Fayoum began to arrive 
in this store on August 15. This seed represents the first picking, in 
1917, in certain districts. 
The numbers of moths caught by the traps each night remained at 
about the same figures, that is, from 2 or 3 to 15 or 20 until September 
1, when the numbers showed a distinct use. In the interval from 
August 15 to September 1, the emerging moths were probably from 
scattered seed and pupae which had been formed between planks in the 
floor and in crevices in the walls and these represented the resting- 
stage larvae from the previous season. 
The great increase in numbers, after September 1, was due to the 
emergence of moths from the short cycle larvae of the 1917 crop. 
The following figures give the catches for each night. It will be 
noted that on the night of September 11-12 there was no light, and 
the trap caught only 8 moths, the windows of the seed store being 
closed. Closing the windows or leaving them open during the night 
does not seem definitely to affect the catch in the trap. 
The Resting Stage 
The most important feature in the life-history of this insect is what is 
called the resting stage of the larva. This resting stage appears to be 
an adaptation of the insect to its environment. For some reason or in 
response to some stimulus which is not at present understood, certain 
of the larvae, after becoming full grown, spin a special kind of cocoon 
