396 



Annals Entomological Society of America [Vol. XIII,. 



no accurate record was made of the evaporating factors for 

 each season, but if a comparison is made between the per- 

 centage of hatch and the rainfall for each year during the period 

 when the eggs are most susceptible to moisture variations (10 to 

 14 days before hatching takes place rapidly) an interesting 

 relationship exists. Table 3 shows the precipitation from 

 March 5 to 31 for 1917 to 1920 and the H in each column 

 indicates the date when rapid hatching occurred. In 1917 and 



TABLE III. 

 Precipitation in inches for March 5-31, 1917, 1918, 1919 and 1920. 



t= trace of rain. 



H = eggs started to hatch rapidly. 



