190 COTTON 



IV. COTTON APHIS. 



When the first few leaves of the cotton plant have 

 formed, you may frequently observe on the under 

 surface many tiny, soft-bodied insects some hav- 

 ing wings, others wingless. Often they are so 

 numerous on the terminals of the buds as to give 

 these buds a black appearance. This pest is the cot- 

 ton aphis. These aphides have passed the winter on 

 various kinds of common weeds, but in spring mi- 

 grate to the cotton plants. Often these tiny in- 

 sects multiply so rapidly as to become very de- 

 structive, doing the damage by sucking the sap 

 from the young leaves. 



They can be destroyed by spraying with kerosene 

 emulsion, whale oil soap, or tobacco water, but 

 this is rarely profitable. As they pass the winter 

 on various kinds of weeds, it is at once apparent 

 that fall and winter plowing, by which the field is 

 cleared of the host plants, will do much toward 

 preventing injury from this pest. 



V. CUT WORMS 



In early spring when young cotton plants are just 

 out of the soil, the farmer when visiting the field 

 in the morning will often find that many plants are 

 cut off at the surface, as if some mischievous person 

 had been trying to discover how many plants he 

 could behead during the night. This destructive 

 work is so familiar to every planter that he at once 

 realizes that it is the work of cut worms. The 

 well-known authors of these midnight raids are 

 the caterpillars or worms, There are a number 

 of different kinds, and the life-history of these sev- 

 eral species varies considerably; in the case of a 



