THE DOCK FALSE-WORM. 



17 



LIFE-HISTORY STUDIES. 



The life-history records given below include records of both normal 

 and parthenogenetic individuals. Where both records occur, these 

 are kept separate, since the normal proportion of individuals of 

 parthenogenetic origin in nature is not known. Records of normal 

 males and females are also kept separate in the complete life-cycle 

 tables, except in the table referring to the fourth generation, the in- 

 dividuals of this generation being still in the larval stage at the time 

 of writing. 



SPRING BROOD OF PUP.E AND ADULTS. 



Pupal period. — The pupation records of the spring brood of pupae 

 and the subsequent emergence of the adults were obtained from the 

 overwintering material collected in the Entiat Valley, Wash.,, on 

 March 17, 1915. Table II gives the length of the pupal period of 4Q) 

 males and 71 females of the spring brood of pupae. The average pupal 

 period for males of this brood is 10.2 days, and for the females 10.6 

 days. 



Table II.- 



-Length of pupal period ofspr 

 Wenatchee, Wi 



ring-brood pupse of the dock false-worm, 

 1915. 



Males. 



1 



Females. 



Date of— 



Days- 





Date of— 



Days- 



Number 









Number 

 of indi- 









of indi- 



















viduals. Pupa- 

 1 tion. 



Emerg- 

 ence. 



Each. 



Total. 



viduals. 



Pupa- 

 tion. 



Emerg- 

 ence. 



Each. 



Total. 



1 



Mar. 31 



Apr. 13 



13 



13 



1 



Mar. 31 



Apr. 14 



14 



14 



1 



...do 



Apr. 14 



14 



14 



2 



Apr. 7 



Apr. 18 



11 



22 



1 



Apr. 5 



Apr. 18 



13 



13 



1 



Apr. 8 



...do 



10 



10 



1 



Apr. 6 



...do..... 



12 



12 



3 



Apr. 10 



Apr. 19 



9 



27 



1 



Apr. 7 



...do 



11 



11 



1 



Apr. 11 



...do 



8 



8 



2 



Apr. 8 



Apr. 19 



11 



22 



2 



Apr. 12 



Apr. 20 



8 



16 



2 



Apr. 9 



...do 



10 



20 



1 



...do 



Apr. 21 



9 



9 



2 



Apr. 10 



...do 



9 



18 



1 



Apr. 13 



Apr. 22 



9 



9 



3 



Apr. 11 



...do 



8 



24 



7 



...do 



Apr. 23 



10 



70 



1 



Apr. 12 



...do 



7 



7 



1 



...do 



Apr. 24 



11 



11 



4 



...do 



Apr. 21 



9 



36 



5 



Apr. 14 



Apr. 23 



9 



45 



1 



...do 



Apr. 23 



11 



11 



4 



...do 



Apr. 24 



10 



40 



3 



Apr. 13 



...do 



10 



30 



1 



...do 



Apr. 25 



11 



11 



2 



...do 



Apr. 24 



11 



22 



2 



Apr. 15 



...do 



10 



20 



1 



Apr. 14 



Apr. 23 



9 



9 



3 



Apr. 16 



...do 



9 



27 



2 



...do 



Apr. 24 



10 



20 



4 



...do 



Apr. 26 



10 



40 



1 



...do 



Apr. 25 



11 



11 



4 



Apr. 17 



...do 



9 



36 



1 



Apr. 15 



Apr. 26 



11 



11 



7 



...do 



Apr. 27 



10 



70 



2 



Apr. 16 



...do 



10 



20 



1 



...do 



Apr. 28 



11 



11 



3 



Apr. 17 



Apr. 27 



10 



30 



1 



Apr. 18 



Apr. 27 



9 



9 



1 



...do 



Apr. 28 



11 



11 



2 



...do 



Apr. 28 



10 



20 



2 



Apr. 19 



Apr. 29 



10 



20 



3 



...do 



Apr. 29 



11 



33 



1 



Apr. 23 



May 5 



12 



12 



2 



Apr. 19 



...do 



10 



20 



1 



Apr. 24 



May 6 



12 



12 



2 

 1 



...do 



...do 



May 2 



May 4 



13 



26 













15 



15 



40 









411 



1 



Apr. 20 



...do 



14 



14 









2 



Apr. 21 



May 5 



14 



28 



Average length in days. . 





.. 10.2 



1 



Apr. 24 



May 6 



12 



12 



Maximum 





.. 14 



1 



Apr. 26 



May 8 



12 



12 



Minimum 





.. 7 



2 



Apr. 27 



...do 



11 



22 









1 



May 4 



May 18 



14 



14 









1 



June 9 



June 16 



7 



7 



71 



758 









Average length in days.. 





.10.6 









Maximum 





. 15 









Minimum. 





. 7 



56815°— Bull. 265—16- 



