PINK BOLLWORM OF COTTON IN MEXICO. 
31 
Willcox (7) states that there is marked reduction in the quantity 
of oil produced and that the quality is of an inferior grade. 
NONPICKABLE COTTON. 
It is in this class that the major portion of the gross damage 
occurs. As has been previously stated, there is a certain percentage of 
the cotton damaged to such an extent as to render it unfit for picking. 
This cotton naturally is left on the plants after the pickings are 
finished. 
An effort has been made to determine the exact portion of the crop 
that is affected in this manner. By selecting what appeared to be 
average-sized plants (according to the number of bolls per plant, 
etc.) in fields of several different average plantations, about 3,000 
plants were examined after the cotton had been picked. These 
plants were examined individually, the total number of bolls on 
each plant and total number of bolls lost on each plant due to attack 
of the pink bollworm being recorded. In counting the total number 
of bolls an empty burr was counted as a boll, and in the calculations 
has the weight of a perfectly sound boll. 
In counting " bolls lost," only bolls or portions of bolls which 
showed plainly that their damage was caused by the pink bollworm were 
taken into consideration. Bolls or portions of bolls that showed 
themselves to be unfit for picking because of conditions other than 
the pink bollworm, such as those attacked by the common bollworm, 
C. obsoleta, or injured by water, heat, and dryness, were counted as 
sound bolls (Table XVI). 
Table XVI. 
— Loss to crop in nonpickable cotton caused by the 
pink bollworm. 
Place. 
Total 
plants. 
Total bolls. 
Total bolls 
lost. 
Percent 
damaged 
Hormiguero 
248 
453 
503 
454 
450 
450 
300 
6,737 
14,977 
15, 117 
20,112 
10,428 
9, 282 
6,297 
1,066 
2,618 
2,942- 
3,768 
2,544 
2,318 
1,325 
15. 82 
17.48 
La Concha 
19.46 
Sanlsidera 
18.73 
Zaragosa 
24.39 
Rosas 
24.97 
Barcelona 
21.04 
Total 
2, 858 
82,950 
16,581 
141.89 
Average 
19.98 
Table XVI shows that of 82,950 bolls produced by 2,858 plants 
16,581 were lost, making a total of 19.98 per cent damage in the non- 
pickable cotton due directly to the attack of the pink bollworm. 
The plantations on which these figures are based represent a true 
average of the entire Laguna. In addition to these plantations, a 
number of other places were visited in different parts of the Laguna 
and the amount of damage found ranged from 15 to 25 per cent, with 
an average of approximately 20 per cent loss due to the pink bollworm, 
which substantiates the accuracy of the foregoing estimates. 
