AND OTHER IXJL'RIOUS INSECTS OF I907 AND I908. 



5^ 



1st Generation, Jan. lU — • 9 young, Experiment No. 4 



11—28 " " " 5 



22— 6 " " " 10 



3— 9 " " " 26 



21—16 " " " 36 



2—28 " " " 45 



11— 6 " " " 54 



25 — Incomplete " " 67 



An average of fifteen young from the first born of each genera- 

 tion. These tables are given for the purpose of afifording a compari- 

 son of productiveness of these grain aphids, and of giving an idea of 

 the frequency of the broods. As previously stated, should we attempt 

 to enumerate all the young from one "stem mother" our figures would 

 take us into the billions, or higher. 



THE CORN LEAF LOUSE. 



Aphis niaidis Fitch. 



Fig. 25. 



Oorn leaf lou.se, Aphis maidis, winged and wingless females 

 and pupa. After Forbes. 



This louse, primarily I'egarded as a corn insect, also attacks gram, 

 and was found at Crookston on July 30th, inside the terininal leaves 

 of young barley, appearing to be the most numerous aphid in the field. 

 As many as thirty individuals were found in a colony, located inside 

 or just at the base of the terminal leaf. It was also found on tassels 

 of corn at Crookston. 



On July 6 a very few were observed on corn at Mora. But on 

 July 18 winged and wingless individuals were found in considerable 

 numbers at St. Anthony Park on young corn tassels, and plenty of the 



