49 



Control. The leaf-blister mite is best controlled by the 

 destruction of all old cotton plants immediately after the 

 crop is reaped, and the picking off of infested leaves as soon 

 as they appear on the young plants. On every estate and 

 in every district where the leaf-blister mite is abundant, 

 there should be a period of several weeks between the 

 destruction of the old plants and the planting of the next 

 crop. All wild cotton near the fields should be cut, as 

 a further precaution. A mixture of lime and sulphur, applied 

 as a dust on the plants, has been found useful iu checking 

 the increase of this pest in the case of serious attack on 

 young plants. The mites are so well protected by the 

 deformities of the plant in which they live, that they are 

 practically out of the reach of any insecticide. Lime and 

 sulphur would only come into contact with them if the mites 

 left the galls to travel across the surface of the leaf. This 

 would probably only happen when the full-grown mites left 

 the old galls in search of young leaf buds in which to deposit 

 eggs and thus provide for the infestation of the developing 

 leaves. 



THE ROLL WORM (Heliothis obsoleta, Htibn.). Lepidoptera. 



This is perhaps one of the most cosmopolitan of all 

 insects, being found in most parts of the temperate and 

 tropical regions of the world. It is a very general feeder, for 

 it attacks and thrives on a great variety of plants, generally 

 preferring the fruit to the leaves. 



Fig". 48. Cotton boll worm. 

 (a) moth ; {b) larva. Slightly enlarged (From U. S. DejH Agric. 



