3o6 



THE ESSENTIALS OF AGRICULTURE 



394. Methods of controlling the codling moth. The codling 

 moth is now controlled almost universally by spraying the trees 

 with an arsenical poison in the form of a liquid. Of late the 

 arsenate of lead, applied at the rate of from two to three pounds 

 to fifty gallons of water, has been used almost entirely. Several 

 treatments a year are necessary for the best results. The first 

 should be given just as the petals are falling. This should be 

 followed in three weeks by a second spray. For the second brood 



of codling moths a treatment should 

 be applied about ten weeks after the 

 first spraying. 



395. The cotton-boll weevil dis- 

 tribution. This insect, a native of 

 Central America, gradually worked its 

 way up through Mexico and was first 

 noticed in Texas about 1890. It is 

 now distributed throughout the greater 

 part of most of the cotton-growing 

 states, and a conservative estimate 

 shows that since the weevil has in- 

 vaded this country it has caused a 

 loss of $20,000,000 annually. 



396. Life history and habits of the 

 cotton-boll weevil. The adult is a 

 small, brownish, stout beetle about 



one fourth of an inch long (Fig. 153). The larva is a footless 

 white grub with a brown head, and is found only within the 

 square or the boll (Fig. 154). The injury is done both by the 

 adults in their feeding and egg laying, and by the grubs which 

 hatch from eggs laid within the bolls or the squares. Both the 

 squares and the bolls are attacked and their contents so dam- 

 aged that they die or fail to produce fiber. The adult weevils 

 feed entirely during the 'day. 



The adult beetles begin to emerge from their hibernation 

 soon after the cotton is up, and continue to emerge until 

 about the time when the cotton squares begin to form. The 



FIG. 153. Cotton-boll weevil. 



(Enlarged six times.) (After 



Hunter and Pierce) 



