STUDIES OF THE PINK BOLLWORM IN MEXICO 
29 
eradication in several large areas. In these areas, however, no effort 
was made to eliminate possible alternate food plants. 
Very extensive searches have been made in the United States to 
find infestation by the pink bollworm in okra and other malvaceous 
plants growing in noncotton zones and in their immediate vicinity. 
In no case has any infestation ever been found in any of these plants. 
The records from Mexico and those from Egypt and other countries 
have shown clearly that the insect can develop in plants other than 
cotton. Taking all the available information together, the conclusion 
seems to be warranted that, in the presence of enormous numbers of 
the insect, such as are found in Mexico and Egypt, there are occasional 
more or less aberrant individuals which attack plants other than 
cotton. With such an attenuated infestation as has occurred in the 
United States, the volume of the moths is so small that the chance 
of attack on other plants is negligible. 
Fig. 10.— Group of cotton plants in tests to determine distance of flight, fenced for protection against 
animals 
DISSEMINATION BY FLIGHT 
In 1921 and 1922 F. F. Bibby conducted experiments to determine 
if possible the distance the pink bollworm moth would normally 
cover by flight. Small groups of plantings (fig. 10) were made at 
isolated points distant from cotton fields and kept under observa- 
tion to determine whether they became infested. Seed free from 
pink bollworms was used. 
In 1921, there were 8 small groups of plants at intervals of 1 mile 
to the north of the fields on the Tlahualilo plantation, which was the 
nearest cotton to these plantings. Each group consisted of about 
a dozen plants, which did not attain any great size and bore little 
fruit, making examination easy. Thorough examinations precluded 
the possibility of moths developing in one group of plants and in- 
festing the next one. The results of the test are given in Table 23. 
