404 SOUTHERN FIELD CROPS 



areas of Texas and Louisiana, the southern portion of 

 Mississippi, and the southern parts of Oklahoma and 

 Arkansas. It may be expected to spread over the entire 

 cotton-growing area of the United States within the next 

 15 to 20 years. 



371. Insect enemies of the boll-weevil. — The weevil 

 has fewer insect enemies than most crop pests. This is 

 probably because the mature weevil is protected with a 

 hard coat, and because in its stages of larva and pupa, 

 when not thus protected, it is inclosed within the square 

 or boll. However, there are some minute insects that 

 lay their eggs in the body of the immature boll-weevil 

 while the latter is still in the square. On hatching, these 

 smaller insects cause the death of the pest. These minute 

 parasites have not destroyed a large proportion of the boll- 

 weevils in Texas, and it remains to be seen whether this 

 class of insects will be more useful in the moister chmate 

 of the Mississippi Valley and eastward. 



In order to utiUze these most fully, the squares that may 

 be picked during the few weeks after the weevils make 

 their appearance, instead of being burned, should be placed 

 loosely in boxes, one side of which is made of screen wire. 

 This should be fine enough (14 meshes to the inch) to pre- 

 vent the escape of the weevils that may hatch ; however, 

 it will permit the escape of their minute insect enemies. 

 If these cages are placed at intervals in the cotton field, 

 it is claimed that these parasites will be turned loose in 

 such quantities as to reduce appreciably the damage done 

 by the boll-weevil. 



The cotton leaf-^orm or caterpillar has been until recently 

 a serious enemy of cotton. (See paragraph 376.) How- 



