256 



MISSOURI AGRICULTURAL REPORT. 



This developing- of some winged individuals takes place more or less 

 throughout the summer, from -the middle of May to the last of October; 

 but understand that not all of the aphids, by any means, that are produced 

 during the summer have wings — only a portion of them. The others 

 are without wings and cannot migrate so as to distribute the species, 

 but must remain upon the plants where the ants take them. The winged, 

 or migrating aphids, like the wingless ones, are unable by themselves to 

 reach the roots of their food plants or to establish themselves and live 

 without the aid of these little red ants. 



To go back to where we had the aphids placed by the ants early in 

 the spring, upon the roots of the young smart-weed that was appearing 

 before the corn is planted ; later there develops in the corn field the 

 fox-tail or pigeon grass, and these ants will now carry some of these 

 aphids also to the roots of this grass, so that we find in the corn field 

 before the corn is planted these ants attending the aphids which they have 



Fig. 15. — Com-Root-Aphis, Aphis, maidiradicis, winged vivaparous female; en- 

 larged sixteen diameters. 



placed upon the roots of both smart-weed and pigeon grass. Later, when 

 the corn is planted and sprouts, the ants make their burrows and nests 

 about the roots of these young corn plants, and before the plant has 

 shown above ground, they carry some of the aphids to the roots of the 

 corn plant, and a colony is established there in the same way as describc-d 

 upon the roots of the other plants. A little later you will find practically 

 all of the aphids transferred to the roots of the corn. 



Understand that these aphids are continually bringing forth living 

 young and their off-spring doing likewise all summer long, so that we 

 have the insects increasing with great rapidity upon the roots of the 

 corn. The greatest amount of damage, however, appears to be done 



