SOME MISCELLANEOUS RESULTSOFTHE WORK OF THE DIVISION 



OF ENTOMOLOGY. 



VII. 



ON SOME OF THE APHIDES AFFECTING GRAINS AND GRASSES OF 

 THE UNITED STATES. 



By Theo. Pergande. 



THE EUROPEAN GRAIN LOUSE. 



(Sipkocoryne avense Fab. — Fig. 1.) 



Up to the present time the writer has been unable to ascertain 

 whether other species described in Europe or this country are identical 

 with this insect or not, though it is quite certain that the accounts 

 or descriptions published by the earlier entomologists of this country 

 on the apple louse all refer to the same species, particularly since the 

 genuine Aphis mall DeGeer was first observed by the writer in the 

 spring of 1897, from which date it has spread through several of the 

 Eastern States. 



The first elaborate account of the common apple louse of the United 

 States was published by Dr. Asa Fitch in his First and Second Report 

 for 1856, under the cognomen of u The apple plant-louse," which he 

 erroneously considered to be identical with the European Aphis mali, 

 to which since his time it has been referred by subsequent authors. 

 These authors took it for granted that Doctor Fitch knew the species 

 well, though all of them were unaware of the range of food plants to 

 which the species adapted itself during its cycle of existence. It is 

 really strange that Fitch, after having seen thousands of the apple 

 louse, should have considered the insect found b} T him on the leaves of 

 the plum to be a different species, which he subsequently described on 

 page 123 of the same report, under the name of Aphis prunifolim, 

 notwithstanding that, as stated by himself, "Its generation and hab- 

 its are so similar to those of the apple plant louse that a separate 

 account would be little more than a repetition of what has already 

 been related." 



To make the history of the species still more complicated, leading 

 later on to man} T errors, Fitch published (on pp. 91, etc., of his Sixth 



5 



