DAMAGE TO SUGAE CANE BY THE SUGAR-CANE BOEER. 3 



tion, however, it will be found that a considerable percentage of the 

 eyes has been destroyed. 



In order to secure definite data as to the extent of tliis injury, a 

 number of borer-infested canes were picked up at random from a 

 pile of cane on a property which probably represents typical condi- 

 tions in Louisiana. The eyes were then counted until 100 were 

 reached, and the number of injured eyes noted. No attention was 

 paid to the amount of borer infestation in each stalk, beyond ascer- 

 taining that at least one borer hole was visible. In the first 100 eyes 

 counted 23 had been destroyed by the borers. On repeating the 

 above experiment it was found that 18 e3^es had been destro^^ed in 

 the second lot of 100, making a total of 41 eyes destroyed out of a 

 total of 200, or 20.5 per cent. The infestation of the plat from 

 which this cane was secured was approximately determined at 53 

 per cent, which would indicate that over 10 per cent of the entire 

 number of eyes in the plat had been destroyed by borers. 



The effect of this is to reduce the stand of cane the following year 

 by reducing the number of viable ej^es in the planted cane. The 

 borers also damage the seed cane to a certain extent by absorbing a 

 considerable amount of the sap or juice wliich nature intended to be 

 used to nourish the buds when they commence to grow, but this 

 injury probably does not assume much economic importance. 



INJURY TO GROWING CANE BY THE SUGAR-CANE BORER. 



When the cane sprouts in the spring a certain amount of damage 

 is done to it by the larvae of the first brood, wliich bore into the 

 hearts of the young and tender shoots. Very frequently the terminal 

 leaves turn 3'ellow, and on being pulled come out of the whorl of the 

 plant bodily. Examination reveals the fact that they have been 

 almost cut off in the heart of the plant, and often the small worm is 

 found in the excavation. It is likely that this source of injury 

 causes considerable damage to the stand of cane, although no experi- 

 ments have yet been made to determine the percentage of injury. 



Borers are also responsible for very considerable damage by wind- 

 storms. After a severe windstorm in the fall the observer can notice 

 two effects upon sugar cane. In some cases the cane will be blown 

 prostrate, being left lying nearly horizontally upon the ground. In 

 other cases many of the stalks are broken b}" the wind, sometimes 

 close to the ground, sometimes in the center or near the top of the 

 cane. In the case of cane which has been blown over, it ^vill often 

 become more or less upright, and in any event it will continue growth. 

 The greatest injur}^ produced u])on it is crooked and bent stalks, 

 which are troublesome to harvest. 



