125 



Cauda is somewhat spoon-shaped, narrowing behind the middle. The 

 beak is short, seldom reaching the middle coxae. The lateral tubercles 

 of the thorax and abdomen are slender and minute. 



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 marks preceding the cauda, and 

 the segments behind it edged with dark. The antennae are rather long, 

 the fourth and fifth segments longer than the basal part of the sixth. 

 The sensory pores of the third antennal segment are thirteen to sixteen 



Fig. 118. The Corn Root-louse, Aphis maidiradicis, winged female, 

 greatly enlarged, with antenna more enlarged. 



in number, variable in size, and irregularly distributed along the under 

 side of the segment. 



The distinctions between this leaf-aphis and the corn root-ajohis are 

 sufficiently indicated by the accompanying figures of both. 



A-phis maidis has been reported at various times as a corn insect, 

 from New York to Texas, Minnesota, and California. The species 

 makes its appearance in mitlsummer, our earliest date being July 9, 

 when specimens were found on young leaves of corn. We have no record 

 whatever to show whence it comes or where it lives preceding this time. 

 Having once begun to breed on the food plants mentioned, it continues 

 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. The latest to develop in the field largely acquire wings, 

 and as the sap supjily in the plants diminishes they fly away. Wingless 

 females, on the other hand, perish on the spot. Indications are thus 

 very strong that this is a migrating species whose second food plant is 



