INSECTS INJURIOUS TO CORN 157 



corn leaves turn yellow or red, and may shrivel and die, partic- 

 ularly if the weather be dry at the time. Broom-corn is consider- 

 ably damaged by a reddened discoloration of the brush, due to a 

 bacterial affection following upon the plant-louse punctures. 



"The wingless form of this aphis about 2 mm. (one-twelfth inch) 

 long and half as wide at the widest part, the body being somewhat 

 ovate in outline. The general color is pale green, with the cauda, 

 cornicles and the greater part of the rostrum, antennae and legs 

 black. The head is marked with two longitudinal dark bands, 

 and the abdomen with a row of black spots on each side 

 and a black patch about the base of the cornicles. The latter 

 are swollen in the middle, making the outlines convex. 



The winged form is somewhat different in color, the head being 

 black and the thorax chiefly black above. 

 The abdomen is pale green, bluish at 

 the sides, with two transverse black 

 bands preceding the cauda, and the seg- 

 ments behind it edged with dark. ' ' These 

 differences between this and the root 

 aphis are shown in the accompanying 

 figures. "Aphis maidis has been re- 

 ported at various times as a corn insect 

 from New York to Texas, Minnesota 

 and California. The species makes its 



appearance in midsummer, our earliest Fl( 3- 13 2- The wingless 

 . , /T ... . . , . T . _ . . female of the corn leaf- 



date (Illinois) being July 9, when speci- aphis much enlarged, 

 mens were found on young leaves of corn. (After Webster, U. S. Dept. 

 We have no record whatever to show 



whence it comes or where it lives preceding this time. Having 

 once commenced to breed on the food-plants mentioned, it con- 

 tinues there until freezing weather overtakes it, when, with the 

 death of its food plants, it gradually disappears, leaving neither 

 eggs nor hibernating adults on or about these plants, and passing 

 the winter we do not know how or where." Its occurrence on bar- 

 ley in Texas in January may throw some light upon its wintering 

 habits in the South. " The latest to develop in the field largely 

 acquire wings, and as the sap supply in the plant diminishes they 

 fly away. Wingless females, on the other hand, perish on the 



