INVESTIGATION OF LIFE HISTORY. 



63 



The egg records of 26 females are given herewith, the beetles being 

 rated as large or small, those having average measurements that ranged 

 above the general average being placed in the former class, and those 

 below in the latter. 





Number. 



Eggs laid. 



Average 

 of each. 





15 



11 



3,848 

 1,846 



256.5 





168 







This indicates that more eggs are normally developed by large 

 females than by small ones. 



It was desirable to determine, however, if the size of the males had 

 any relation to the number of eggs produced, for if this were true the 

 reliability of the data above given might be open to question. 



Accordingly, typical data were secured from 9 males and 9 females 

 which had been mated according to size, and are as follows: 





Eggs de- 

 posited. 



Total. 



Average 



per 

 female. 



Large male and large female 



{ Z\ 704 



1 i52 * *** 



352 



Small male and large female 



271 



Small male and small female 



\ 342 



/ 189 

 \ 175 

 f 134 

 \ 207 

 I • 85 



} 364 

 I 426 





Large male and small female 



142 







This indicates conclusively that the size of the males is not an 

 important factor relative to the number of eggs that the females will 

 produce, and although there is quite a wide variation in the number 

 of eggs laid by either large or small females, it demonstrates that 

 large females will lay more eggs even when mated with a small male. 



Sexes of Beetles Reared. 



In order to determine the proportion of the different sexes of 

 C. sycoplianta reared from eggs laid, a careful record was kept of the 

 sexes of the beetles that emerged in the spring of 1909 and 1910. 



Of 71 beetles that were secured 39 were males and 32 were females 

 (1909). 



Of 512 beetles that were secured 261 were males and 251 were 

 females (1910). 



This indicates that under laboratory conditions practically the same 

 number of each sex is reared. 



