WALNUT APHIDES IN CALIFORNIA. 



11 



Table IV. — Life cycle of the summer generations of Chroma-phis juglandicola, San Jose, 



Cal., 1911. 



Generation No. 



No. indi- 

 vidual. 



Date of— 



Life 

 cycle. 



Form of indi- 

 vidual. 



Deposi- 

 tion. 



Reach- 

 ins: adult 

 state. 











Days. 







( 1 



June 8 



June 28 



20 



Viviparous. 





2 



16 



July 1 



15 



Do. 





3 



16 



1 



15 



Do. 



IV 



4 

 5 



16 

 16 



1 

 2 



15 

 16 



Do. 

 Do. 







6 



16 



2 



16 



Do. 





7 



16 



2 



16 



Do. 





1 



July 1 



15 



14 



Do. 



V 



2 

 3 



1 

 1 



15 

 17 



14 

 16 



Do. 

 Do. 







4 



1 



18 



17 



Do. 





1 



15 



31 



16 



Do. 





2 



15 



31 



16 



Do. 





3 



15 



31 



16 



Do. 





4 



15 



31 



16 



Do. 





5 



15 



31 



16 



Do. 





6 



15 



31 



16 



Do. 





7 



15 



31 



16 



Do. 





8 



16 



Aug. 1 



16 



Do. 





9 



16 



1 



16 



Do. 





10 



16 



1 



16 



Do. 



VI 



11 

 12 



16 

 16 



2 

 2 



17 

 17 



Do. 

 Do. 







13 



16 



2 



17 



Do. 





14 



16 



2 



17 



Do. 





15 



17 



2 



16 



Do. 





16 



17 



2 



16 



Do. 





17 



17 



2 



16 



Do. 





18 



17 



3 



17 



Do. 





19 



17 



4 



18 



Do. 





20 



18 



5 



18 



Do. 





21 



18 



6 



19 



Do. 





22 



18 



6 



19 



Do. 





1 



Aug. 2 



17 



15 



Do. 





2 



2 



17 



15 



Do. 



VII 



3 



2 



17 



15 



Do. 

 Do. 





4 





19 



17 





5 



3 



20 



17 



Do. 





6 



3 



20 



17 



Do. 





7 



3 



20 



17 



Do. 





f 1 



18 



Sept. 1 



14 



Do. 





2 



19 



2 



14 



Oviparous. 





3 



19 



2 



14 



Do. 





4 



19 



3 



15 



Do. 





5 



19 



3 



15 



Do. 





6 



19 



3 



15 



Do. 





7 



19 



3 



15 



Do. 





8 



19 



3 



15 



Do. 



VIII 



9 

 10 



19 

 20 



3 

 4 



15 

 15 



Do. 

 Do. 







11 



20 



4 



15 



Do. 





12 



20 



4 



15 



Do. 





13 



20 



6 



17 



Viviparous. 





14 



20 



6 



17 



Oviparous. 





15 



20 



6 



17 



Do. 





16 



20 



7 



18 



Viviparous. 





1 



Sept. 5 



30 



25 



Oviparous. 





2 



5 



Oct. 1 



26 



Do. 





3 



5 



6 



31 



Viviparous. 





4 



5 



6 



31 



Do. 





5 



5 



8 



33 



Do. 





6 



5 



8 



33 



Do. 





7 



7 



9 



32 



Do. 



IX 



8 

 9 



7 

 7 



11 

 13 



34 

 36 



Do. 

 Do. 







10 



7 



14 



37 



Do. 





11 



7 



14 



37 



Do. 





12 



8 



12 



34 



Do. 





13 



8 



17 



39 



Do. 





1 14 



8 



17 



39 



Do. 



