12 MASS. EXPERIMENT STATION BULLETIN 375 



Table 6. Number of Eggs of the Citrus Mealybug Eaten by Larvae of 

 Cryptolaemus. Waltham, Mass., 1935 and 1937. 



*Larvae did not complete growth nor pupate; number of eggs represents 

 those eaten before death. 



constant amount of food is necessary to provide the growth for complete 

 larval development. The maximum number of eggs eaten was 1689 and 

 the minimum number was 1033, and it is apparent that the amount of food 

 necessary for complete larval growth in terms of eggs of the citrus mealy- 

 bug is about 1350. Variations in the number of eggs eaten are explained 

 by natural vigor of individuals as indicated by diflference in size. 



Table 7. Rate of Feeding of Cryptolaemus Larvae on Eggs of Citrus 



Mealybug in 10-Day Intervals at Constant Temperatures. 



Waltham, Mass., 1935. 



Number of larvae 



Average length of feeding period (days) 



Average number of eggs eaten during life 73.33 



Average number of eggs eaten per day . . 2.2 5 



Average number of eggs eaten per day by 

 10-day periods: 



1-10 days 2.13 



11-20 days 2.33 {:>)** 



21-30 days 4.23 



31-40 days 1.S5 (5)** 



41-.50 days 



51-60 days 



61-70 days 



71-80 days 



*None completed growth and pupated. 

 ** Figure in parenthesis represents the number of larvae ol) 



