THE COKN ROOT-APHIS. 



Although the corn root-aphis (figs. 3, 4) was not definite!}^ described 

 until 1891, its presence in the cornfields of Illinois was noticed b}^ 

 Mr. B. D. Walsh in 1862, near Rock Island, and these two corn 

 aphides were mide the subject of a paper contributed by him to 

 the Transactions of the Illinois State Agricultural Societ3^^' Mr. 

 Walsh, who was afterwards the first State entomologist of Illinois, 

 stated that his attention was called to the " lice" on the roots of corn 

 in this field in the latter part of May, 1862, and about a fortnight later 

 he visited the field in person. He illustrates a section of corn root 

 "as I saw it with my own eyes, swarming with these tin}" pests." 

 Further, he states that from wingless specimens, secured at the time 

 of his visit, he afterwards reared 15 winged females. From the 

 fact that the description of thei leaf -aphis by Doctor Fitch '' agrees 



Fig. 3. — The corn root-aphis (Ap/n's iiKiidi-nKlicis): Winged foniiilo. ^Nlueh enlarged (orifrinsil). 



tolerably well" with that of the species that he found attacking the 

 roots in Jiuie, he suspected that the two were identical. An illustra- 

 tion of the winged female reared from the roots does not, however, 

 tend to convince one of the correctness of his opinion, as it best repre- 

 sents the winged I'oot-aphis and rather sustains the fact that the root- 

 aphides were present on the roots of corn at that time, in the vicinity 

 of Rock I.sland, and that from some of these he succeeded in rearing 

 winged adults in June. While this is not in the least surprising it is 

 nevertheless interesting as being a record of the original discovery of 

 the root-aphis and of (he discovery and rearing of the winged female. 

 The statesmen t made that the root-aphis was attended by little brown 

 ants is still further evidence of the Validity of these observations, 

 however incorrect Walsh's conclusions therefrom may have l)een. As 

 a matter of fact, up to about that time spring wheat culture had domi- 



|Cir.8t;] 



« Vol. 5, pp. 491-497, 1861-64. 



