﻿14 



BtTLLEMN 1357, U. S. DEPABOTMEKT OE AGMCtJLTURB 



JipfS) says : " No male adults have been seen at any time in our three 

 years of observation with this species." Males are known to occur 

 out of doors, and these observations indicate possible thelyotoky in 

 the greenhouse forms. Wliether or not they are fertilized, it is an 

 outstanding fact that practically all the eggs in- the masses observed 

 in greenhouses have hatched. 



Although 25 adults which emerged on the same day were removed 

 from the rearing cage and confined singly, so that the only possible 

 access to males was before they were isolated, three of them deposited 

 eggs. In another case eggs were obtained from two reared adults 

 which were segregated immediately after emergence. In this con- 

 nection Peterson (^^, 'p. J^73) observes that the ovaries of newly 

 emerged adults are in an immature condition and do not develop to 

 any extent until the adult has consumed some food. At first the 



100 

 "g 95 

 S 90 

 §. 95 



« 75 



g 70 



^ 65<< 



■5 60 



^ 55 



E 60 



I 45 



Z 40 



<- 















































_ 







— 



— 



— 



Ten- 



perature 









98 

 96 

 94 

 92 

 90 



as 



66 

 84 

 62 

 60 

 76 

 76 

 74 

 72 

 70 

 66 

















































Number of eggs laid 



















































































































)\ 



L, 



















































- 



\ 









































































/ 





\ 























> 





















































\ 

















/ 







\ 















































/ 























/ 







", 

































s 















,' 























;' 









'^^ 













































/ 































\ 













































/ 





















I 











































\ 























\ 











/ 





















































1 























/ 













K 

































\. 









1 



















\ 





I 













1 '^ 

















/ 





-A 



^ 











■i.. 



























i 



k 

















^^ 



L 











'' 





















^^ 



-- 



/ 











































^ 











































































^^ 





/ 

















































































































1 













































































/ 













































































/ 







































































































































































































A 











































y 

























\ 









i 







I 

























y 















\ 



> 









/ 



\ 







/ 



1 









\ 







\ 

























/ 















\ 



/ 









/ 





\ 







/ 





K 







/ 







\ 















. 



^ N 











s 



V 



\ 













^ 





w 



f 





\ 







' 













PM AM PM J ^ AM ^ ^ PM AM ^ ^ PM 



►-• 



July II 



I0yl2 ^2 4 6 6 10 12 2 4 6 6 10^ 12 ^2 4 6 6 10 12 2 4 6 6 IQ ,I2 ^ 2 4 6 6 10 12 2 4 6 8 lOy 

 July 12 



July 13 



July 14 



Fig. 6.- 



-Egg deposition by strawberry rootwonn adults. Records every two hours 

 July 11 to 14, incluslTe, Doylestown, Pa., 1922 



from 



abdomen is very soft and does not become full and hardened until 

 seven days after emergence, so that, although possible, it is doubtful 

 whether mating takes place while the female is in this undeveloped 

 state. Furthermore, as is shown in Table 7, no eggs were laid by 

 reared individuals until 19 days after emergence, or 18 days after 

 they were isolated. From the foregoing circumstantial evidence it 

 would appear that parthenogenesis is a possible feature of the biol- 

 ogy of this insect under greenhouse conditions. 



ovrposirroN 



Oviposition may take place, at least to a limited extent, through- 

 out the year, since the eggs have been obtained from caged beetles 

 in each month. In the greenhouse, however, most of the eggs were 

 laid in the spring and early summer months. The earliest records 

 of the finding of eggs in the rose houses are March 9, 1920, March 

 1, 1921, and March 14, 1922, and after these dates eggs could be 



