PINK BOLLWORM OF COTTON IN MEXICO. 
29 
The damaged seed from the first pick weighed less per seed than from 
the second pick, and the damage per seed from the first pick was 
greater than in the second pick. This is probably because the bolls 
from the first pick were attacked when they were greener and the 
seeds were attacked when they were more immature than in the 
other picks. There is no indication that the number of seeds per 
boll is reduced on account of pink bollworm attack, as pointed out by 
Gough. Unfortunately, the sample of the third pick is from a dif- 
ferent plantation and is not quite comparable with the other samples. 
It may be pointed out, however, that the average weight of the sound 
seed in the second and third picks is almost the same and that the 
loss in the individual attacked seed is greater in the third than in the 
second pick. This is thought to be because a much larger number of 
larva? had prepared to hibernate in the third pick and a hibernating 
larva needs all the available space, especially in the single seed, 
and had eaten out the kernels of the seed cleaner to prepare this space. 
From the data given in Table XIII the loss in weight of the seed in 
the different picks can be calculated, and this is summarized in Table 
XIV. 
Table XIV. — Summary of table showing^ the loss in weight of the seed from the different 
picks due to pink bollworm attack. 
Pick. 
Actual 
weight 
of seed 
(grams). 
Loss in 
weight 
of in- 
fested 
seed 
(grams). 
Corrected 
weight 
of seed 
(grams). 
Per cent 
of loss in 
infested 
seed. 
Per cent 
of total 
seed lost. 
Remarks. 
First 
261.45 
278. 78 
305. 50 
8.42 
13.40 
72.38 
269. 88 
292. 18 
377.88 
3.1 
4.6 
19.1 
1.24 
1.84 
3.82 
First pick=40 per cent crop. 
Second pick =40 per cent crop. 
Third pick =20 per cent crop. 
Second 
Third 
Total 
6.90 
Table XIV shows a loss of 3.1 per cent in the weight of the seed 
from the first pick, 4.6 per cent of the second pick, and 19.1 per cent 
in the third pick. The data secured in 1919 showed that 40 per cent 
of the crop was harvested in the first pick, 40 per cent in the second, 
and 20 per cent in the third. The losses in the seed from the dif- 
ferent picks when given their proportionate weights with respect to 
the proportion of the total crop harvested in each pick show that 
1.24 per cent of the total seed was lost in the first pick, 1.84 per cent 
in the second pick, 3.82 per cent in the third pick, or that a total of 
6.90 per cent by weight of the seed is lost due to the attacks of the 
pink bollworm in the pickable cotton. 
When the above-mentioned field samples of seed cotton were 
ginned the seed of the first, second, and third picks were placed in 
separate piles. Using a 20-liter measure, an equal number of weigh- 
