AN ECONOMIC ENTOMOLOGY. 



corn is the favorite food, and they will attack it in preference to 

 everything else. This preference is utilized by planting corn in 

 cotton-fields in such a way that the ears are in attractive condi- 

 tion at the time when the moths would otherwise oviposit in the 

 bolls. Before the caterpillars come to maturity they can be de- 

 stroyed by hand in the ears, or the corn can be cut and fed to 

 stock, together with the caterpillars. This is really the most 



Fig. 342. 



Heliothis armiger in all stages.— c, b, egg, enlarged ; c, larva ; d, pupa in its under- 

 ground cell ; e,f, moths. 



satisfactory way of dealing with this insect in cotton-fields. By 

 providing early corn for the early broods of larvae, and destroying 

 it before they mature, the species can be kept down to harmless 

 numbers later in the season. The adoption of a more diversified 

 agriculture will have a tendency to lessen injury to the cotton, 

 and if systematic fall ploughing of corn-fields be practised, it 

 will soon become insignificant. There are two or three broods 

 in the latitude of New Jersey and even more southwardly, while 

 in its most northern range a single brood only is normal. In 

 September or early October the caterpillars that mature in corn 

 go underground and change to pupae, passing the winter in this 



