STUDIES OF THE PINK BOLLWOKM IN MEXICO 
21 
made in a number of representative plantations in the Laguna. 
In 1921 the counts were made in November and the first part of 
December. In 1922 the counts in the unirrigated fields were made in 
Fig. 8.— Characteristic pink bollworm damage, showing type of bolls classed as "nonpickable" 
the latter part of September and the first part of October and those 
in the irrigated fields during the latter part of November. A frost 
on October 30, 1921, killed all the cotton and consequently no green 
