﻿STUDIES OF THE PIISTK BOLLWOKM IIST MEXICO 



35 



mortality of the larvge 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 

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Fig, 12. — Parasitizod larvse in Vjlooms and total blooms infested with the pink bollworm on a 



half-acie 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 1 7 per cent of the maximum, 

 witli only 18 infested, and 3 parasitized larvae. Few parasitized 

 larva were founfl in blooms after this. Of 105 larvae collected 

 from infested blooms on October 1, none were found to bo infested. 



Two species of parasites were found to bo common. These are 

 Microhracon rndlitor fSay) and Ilahrohracon gdechiae (Ashm.). 



