THE SUGAR-CANE MOTH BORER. 49 



1'he senior writer was told by a reliable plantation manager of the 

 planting of borer- free cane at Pharr, Tex., in 1916. Although there 

 were no borers in the seed cane, which had been procured from a .sec- 

 tion known to have none, the cane was badly infested at the grinding 

 season. 



A field of cane planted with borer- free seed somewhat resembles 

 a field of corn in its relation to borers. Undoubtedly there are often 

 no borers in the cornfield when the seed is planted, yet there may be 

 a heavy infestation later. The borer moths evidently fly into the 

 cornfield during the early spring, and they can as easily fly into a 

 field planted with borer-free seed cane. 



SHAVING CANE STUBBLE. 



Some sugar planters believe that " shaving " the cane stubble in the 

 spring reduces the subsequent infestation by the moth borer. This 

 operation is done with a " stubble shaver," a wheeled instrument hav- 

 ing a straight or disk blade set horizontally, which cuts away the 

 upper inch or so of the stubble. Borers are supposed to be in the 

 upper portion, and when it is removed they are believed to be killed. 



The authors' observations show, however, that few borers can be 

 found in the stubble. Many stubble shavings have been examined, 

 and no borers have been found in any of them. 



It is apparent, therefore, that shaving the stubble can not be re- 

 garded as an effective measure for the control of the moth borer. 



IMMEKSION AND FUMIGATION OF INFESTED SEED CANE. 



Various entomologists who have made a special study of insects 

 injurious to sugar cane have experimented with hydrocyanic-acid 

 gas and various liquids in attempts to disinfect seed cane before 

 planting. In these experiments, the seed cane has been subjected to 

 the gas in various strengths, and has been soaked in different solutions 

 from one minute or less to at least three hours. The consensus of 

 opinion at present seems to be that treatment of infested stalks is 

 neither practicable on a large scale nor efficient as a means of con- 

 trolling insects on an infested plantation. 



At the Sugar Experiment Station at Audubon Park, New Orleans, 

 all cane cuttings sent out are subjected to a rigid inspection and wash- 

 ing in fish-oil soap solution (^ pound soap to 1 gallon of water). 

 Only cane not bored by the moth borer is sent out, and this is thor- 

 oughly washed in fish-oil soap solution to kill the mealybugs (Pseu- 

 docoQcus calceolariae Maskell), and afterwards is inspected to ascer- 

 tain whether»any mealybugs have escaped. This procedure results in 

 the distribution of absolutely insect-free seed cane, which is highly 

 desirable, as otherwise the experiment station would become a 

 center of insect distribution. 

 83363°— 19— Bull. 746 4 



