218 MANUAL OF VEGETABLE-GARDEN, INSECTS 



Tomatoes can also be partially protected from the corn ear- 

 worm by using corn as a trap crop on which, in preference to 

 the tomatoes, the moths will lay their eggs. Two rows of corn 

 should be planted for every ten or twenty rows of tomatoes 

 and so timed as to come into silk when the first tomatoes are 

 forming. It should be cut and destroyed before the cater- 

 pillars reach maturity. 



References 



Comstock, Rept. Cotton Insects, pp. 287-315. 1879. 



Riley, 4th Rept. U. S. Ent. Comm., pp. 355-384. 1885. 



Mally, Rept. on Bollworm, Tex. Agr. Col. 1902. 



U. S. Farm. Bull. 191. 1904. 



U. S. Bur. Ent. Bull. 50. 1905. Bibliographij. 



U. S. Farm. Bull. 290. 1907. 



Ky. Agr. Exp. Sta. Bull. 187. 1914. 



The Corn Root-Aphis 



Aphis maidi-radicis Forbes 



Although the corn root-aphis is generally distributed through- 

 out the United States east of the 100th meridian, it is most 

 injurious in the corn belt and in New Jersey, Delaware and 

 eastern Pennsylvania. In the South Atlantic states, it has 

 proved a troublesome pest of cotton and has also been known 

 to infest the roots of cultivated asters in Illinois. There is 

 some doubt as to many of the wild food plants of the corn 

 root-aphis because of confusion with a similar species, Aphis 

 middletoni Thomas, often found on the roots of certain wild 

 plants such as asters and Erigeron. It is, however, definitely 

 recorded from smartweed, knotweed, crab-grass, purslane, dock, 

 foxtail, fleabane, mustard, sorrel, plantain, pigweed, great 

 ragweed, thorny amaranth, green amaranth, Roman wormwood, 

 dog fennel, shepherd's purse, lamb's quarters, poverty weed, 

 buttonweed, purplish cudweed, sneezeweed, pineweed, dwarf 



