INSECTS INJURIOUS TO COTTON 247 



important factors which have aided in the control of the cotton 

 worm, so that it is by no means as much of an enemy of the cotton 

 crop as formerly. Among the most important of these, both 

 from an entomological and general agricultural standpoint, is 

 the diversification and rotation of crops, now coming to "be more 

 and more practiced by the progressive agriculturists of the South. 

 This alone largely prevents the rapid spread of the pest. Since 

 the seed has become such a valuable product of cotton, smaller 

 varieties with many seeds and a short fibre are being grown, 

 in contrast to the rank-growing, long-fibre sorts formerly pre- 

 ferred. Thus the rows are more open, the work of the worms 

 is more readily detected and the poison more easily applied. 



Other Caterpillars Injuring the Foliage 



Several of our common caterpillars which ordinarily feed upon 

 various weeds frequently attack cotton foliage in restricted local- 

 ities and do more or less serious damage. They may be readily 

 controlled by keeping down the weeds upon which they normally 

 feed and multiply and by dusting the foliage as for the cotton 

 worm as soon as they are noticed upon the cotton in any numbers. 



Among the more common of these leaf-eating caterpillars 

 is the Garden Web worm* (see page 406) , which may be recognized 

 by the fine silken web which it spins over the young plants. 

 Another is the White-lined Sphinx Caterpillar,! a yellowish- 

 green caterpillar with black eye-spots and faint stripes, varying 

 to blackish with yellow spots, and distinguishable from most 

 other cotton caterpillars by the horn, characteristic of sphingid 

 caterpillars, at the tip of the abdomen. The Salt-marsh Cater- 

 pillar J which is one of our best-known " woolly bear " cater- 

 pillars, covered with black and red hairs, has frequently stripped 

 cotton of foliage in Texas, as does the Fall Army Worm (see page 

 118), when it becomes locally overabundant. Many other species 

 might be mentioned which do more or less local injury. 



* Loxoslege similalis Guen. Family Pyralidae. 

 t Deilephila lineata Fab. Family Sphingidce. 

 J Estigmene acrcea Drury. Family Arctiidce. 



