2 14 DAVENPORT ACADEMY OF SCIENCES. 



Phylloxera cary^-fallax Riley. 

 PI. IX., figs. 52-53; PL XI., figs. 71-74- 



Phylloxera caryae-fallax Riley. Seventh Rep. Nox. and Ben. 

 Ins. of Mo., p. 118. 



Phylloxera caryts-fallax Thomas. Eighth Rep. Nox. and Ben. 

 Ins. of Ills., p. 164. 



Considerable doubt has existed until lately in my mind as to 

 the identity of the species briefly referred to under this name by 

 Walsh in his "First Ann. Rep. of the Nox. Ins. of Ills.," p. 23, 

 and that described by Riley under the same name in the ' 'Seventh 

 Ann. Rep. on the Nox. and Ben. Insects of Mo.," p. 118. 

 Walsh states that he never found a winged insect either in this 

 gall or in those of c. -semen and c- folia, though he has opened 

 and examined hundreds of them. My observations regarding 

 this peculiar gall, extending as far back as 1872, run counter to 

 those of Walsh, for I have found this particular gall swarming 

 with the winged female. 



To account for this apparent discrepancy in independent obser- 

 vations, it may be stated that my own observations were made 

 from early May until June, and that these made by Mr. Walsh 

 were from the 17th until the end of June, or at a time when the 

 winged form had already forsaken the galls. What, then, were 

 the numerous larvse (?) with which he found the galls swarm- 

 ing, and what was their office? They could not well form new 

 galls, as the season for that purpose was already too far 

 advanced ! 



The explanation will doubtless be found in the following facts : 

 If the galls be opened early in May, or before the nipple has 

 opened, they will be found filled with winged insects, pupae, 

 numerous eggs, and what appear to be larvse. These supposed 

 larvae, however, upon careful examination, are not larvae hatched 

 from eggs deposited by the stem-mother, but the true sexual 

 individuals, both males and females, produced from eggs depos- 

 ited freely by the winged females. In thisspecieSi therefore, th^ 

 se'xed individuals are (in part at least) produced within the 

 original gall, though . winged females subsequently perform the 

 true function of migrants and leave the galls to carry their 

 sexed young elsewhere. 



