150 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



marginal spots and small dark specks over the surface. The 

 antennae are dark and the legs blackish. 



The corn-root aphis occurs throughout the principal corn- 

 growing States, but has been most destructive where corn is 

 most extensively grown and is often planted year after year 

 on the same land. Dr. Forbes, to whom we are indebted for 

 most of our knowledge of this pest,* has observed fields of 

 corn in Illinois planted in corn for the second season totally ruined 

 by the root-aphis. Broom-corn and sorghum are the only other 

 cultivated crops which have been injured^ but the list of food 



FIG. 127. The corn root-aphis (Aphis maidi-radids Forbes): at left, ovip- 

 arous female; a, hind tibia, showing sensoria; at right, male; a, antenna 

 much enlarged. (After Forbes.) 



plants includes smartweed, purslane, ragweed, foxtail, and crab 

 grasses, and many other weeds and grasses which spring up in 

 the corn-field. In South Carolina Professor A. F. Conradi has 

 found it injuring cotton. 



* S. A. Forbes, 17th, 18th, and 25th Reports of the State Entomologist 

 of Illinois; Bulletin 60, Bureau of Entomology, U. S. Dept. Agr., p. 29; Bul- 

 letins 104, 130, and 178, Illinois Agr. Exp. Sta. [See also J. J. Davis, Bulletin 

 12, Part VIII, Technical Series, and U. S. Dept. Bulletin 891, Bureau of 

 Entomology, U. S. Dept. Agr., and F. M . Webster, Circular 86, Bureau of 

 Entomology, U. S. Dept. Agr. 



