134 FIELD CROPS FOR THE COTTON-BELT 



under the shade of the branches than in those squares 

 that are brought to the middles between the rows. As a 

 result of this discovery, W. E. Hinds has devised a chain 

 cultivator which brings the infested squares out of the 

 shade of the plants, leaving them exposed to the sun mid- 

 way between the rows. 



In humid regions, provided labor is cheap, it is rec- 

 ommended that the first-appearing weevils and first- 

 infested squares be picked from the plants. The squares 

 should not be destroyed but should be placed in screened 

 cages, which will prevent the escape of the weevils but 

 will permit the parasitic enemies of the weevils to escape 

 and continue in the destruction of more weevils. All 

 methods of poisoning the weevils that have been so far 

 tried have given disappointing results. 



THE COTTON BOLL-WORM (Heliothis obsoleto) 



Next to the cotton boll-weevil, the cotton boll-worm is 

 probably the most destructive insect enemy of the cotton 

 plant. 



160. Description. When full grown the cotton boll- 

 worm is from an inch to an inch and a half in length. 

 The different individuals vary as regards their color and 

 markings, almost every gradation occurring from a pale 

 green through a pinkish or brown to almost black. When 

 first hatched they are very small and often go unnoticed 

 until their injury becomes rather severe. They are found 

 on cotton from the time the squares are formed but their 

 principal injury is noticeable late in the summer or fall 

 after the bolls have grown to normal size. 



161. Life history. As in the case of the cotton boll- 

 weevil, the life cycle of the cotton boll-worm comprises 

 four distinct stages the egg, the larva, pupa, and adult. 



