BIOLOGICAL STUDIES ON THREE APHIDID^. 



133 



Table V. — Data of iiulivi<J>iaJ experiments tvitJi Apliis Diaidi-radicis, oviparous 



generation, 1906. 



" Romoved. 



^ Ago when removed. 



The average of 47 records is IG-^- days. The average total life of 

 38 individuals was 30.9-)- days, with a maximum (1906) of 50 days. 

 In 1905 one aphis of this oviparous generation lived to the age of 

 61 days. A few records were made as to the number of eggs laid 

 hy individual females, and this was found to vary up to 10, which 

 was probably not far from the actual number that is ordinarily laid, 

 though 4 was the average number in the counts made. Eggs were 

 found in the bodies of nearly all the females after death ; the poten- 

 tial reproductive capacity of the female seems to exceed her vitality. 



It is easy to distinguish immature males from oviparous females 

 after the second molt by their color. The males have a distinct 

 reddish hue, while the females have a greenish color. 



