STUDIES OF THE PINK BOLLWORM IN MEXICO 
35 
mortality of the larvae in the picked blooms was observed. This 
was found to be caused by parasites. Records were then kept of 
the parasitized larvae also. The results of this test are shown in 
Figure 12. 
The parasites more or less followed the course of the pink boll- 
worm infestation at first, but afterward did not keep pace with its 
rapid increase. 
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Fig. 12. 
-Parasitized larvae in blooms and total blooms infested with the pink bollworm on a 
half-acre plat, 1921 
The peak in blooming was reached on July 11. Regular counts 
were discontinued after July 15. On July 19 and August 2, two 
complete counts were made. In the first the maximum of 972 
infested blooms and 114 parasites was reached. By August 2 the 
total number of blooms had dropped to 17 per cent of the maximum, 
with only 18 infested, and 3 parasitized larvae. Few parasitized 
larvae were found in blooms after this. Of 165 larvae collected 
from infested blooms on October 1, none were found to be infested. 
Two species of parasites were found to be common. These are 
Microbracon mellitor (Say) and Habrobracon gelechiae (Ashm.). 
