104 



PAPERS ON CEREAL AND FORAGE INSECTS. 



Fig. 56. — The corn root-aphis : Ovipa- 

 rous female and hind tibia. (From 

 Forbes.) 



from tropical America; and Chenopodium album, Capsella bitrsa- 



pastorls, Brassica oleracea, and B. nigra, Polygonum' persicaria, 



Rumex crispus, and Anthemis co- 

 tula, which are adventitious from 

 Europe or have been naturalized 

 from Europe. They are all annuals 

 except a few which are sometimes 

 biennials. 



During March and April, 1910, in 

 the vicinity of San Benito, Tex., the 

 writer found this species infesting 

 the roots of the following unculti- 

 vated plants: Vervain {Verbena 

 canadensis), common nightshade 

 (Solanum nigrum), skullcap (Scu- 

 tellaria drummondii), Teucrium 

 laciniatum, amaranth (Amaran- 

 th vs sp. ) . Selenia ( ? ) sp., and at 

 Brownsville on the roots of Iva 

 xa?it ht folia ( ?). 

 Nothing was found to indicate that it had attacked either corn or 



cotton, although further investigations will be required to either 



prove or disprove its occurrence on 



these or other cultivated plants. 



INJURY TO CORN. 



Aphis maidi-radicis has been par- 

 ticularly injurious to corn in Mary- 

 land, Ohio, Indiana, and Illinois, and 

 has done serious injury to this crop 

 in eastern Pennsylvania, New Jersey, 

 the Virginias, and the Carolinas. In 

 badly infested fields the crop is some- 

 times almost entirely lost, as shown in 

 the accompanying illustration (Plate 

 V, fig. 1), from a photograph by Mr. 

 W. J. Phillips, of a field in Indiana. 



In Illinois its seasonal history, ac- 

 cording to Mr. J. J. Davis, a is, in brief, 

 as follows: The eggs may be found 

 hatching in the field from April 8 to 

 May 22, and from ten to twenty-two generations may follow. Sexual 

 forms (figs. 56-58) are produced in the latter part of September or in 



Fig. 57. — The corn root-aphis 

 less male and antenna. 

 Forbes.) 



Wing- 

 (From 



a Loc. cit. 



