86 Annals Entomological Society of America [Vol.11, 



This experiment was several times repeated. Female Lysiphle- 

 bus reared under cover from Aphis niaidiradicis were in two cases 

 bred into Toxoptera and adults obtained. Female Lysiphlehus 

 were reared from Aphis setarice from the field and the issuing 

 parasites in two cases were bred into Toxoptera and adults 

 secured. This was also repeated several times. Female Lysi- 

 phlehus reared from Aphis maidis from the field, the adult par- 

 asites were bred into Toxoptera and adults emerged. Repeated 

 several times. Female Lysiphlehus from Aphis gossypii from New 

 Mexico and the adults successfully bred into Toxoptera. Female 

 Lysiphlehus reared from A pins setarice from the field were bred 

 into Toxoptera thence into .4 . maidiradicis and back into Toxop- 

 tera. Female Lysiphlehus from ^4. setarice taken from the field 

 and bred into Toxoptera, then back into A. setarice again into 

 Toxoptera and then into .4. hrassiccc from which adults were 

 secured. 



In many cases these breedings were reversed. The only cases 

 of failures were in attempting to breed Lysiphlehus from Toxop- 

 tera into Chaitophoriis] and in attempting to breed Lysiphlehus 

 from Toxoptera into Macrosiphum rudheckicB. These experiments 

 were reversed with the same results. 



These experiments will be carried further another year, as it 

 seems that host habits if we may term them such may possibly 

 divide the specific position of the parasite in future. 



The following diagram will serve to illustrate the additional 

 host insects of the species of Lysiphlehus and Aphelinus that are 

 known to also attack Toxoptera. This shows the varied host 

 sources from which parasites may come in case of a serious inva- 

 sion of Toxoptera. 



