6 DAMAGE TO SUGAE CAXE BY THE SUGAE-CANE BOEEE. 



lowest infestation found in the middle of the plat. On the other 

 hand, in 6 cases out of 7, where comparison could be made, the 

 lowest infestation was found at the ends of the plats. It may be 

 said in general that the liighest infestation will be found in the most 

 luxuriant cane. 



CHARACTER OF INFESTATION IN PLANT CANE AND STUBBLE CANE. 



In fall plant cane the majority of the infestation is in the upper 

 half of the cane, while in stubble cane the infestation is more notice- 

 able near the ground, although the whole stalk is more or less infested. 

 This may be due to the earlier sprouting of the stubble cane in the 

 spring, thus causing it to be hable to attack from the early broods 

 of borers; and also a certain number of borers may hibernate in the 

 stubble, thus being present in the spring to infest the early sprouting 

 cane. On the other hand, fall plant cane does not appear above the 

 ground as early in the spring as stubble, and as the adults that 

 appear in the seed cane are too delicate to dig through the soil to the 

 surface they perish underground. A field of fall plant cane may be 

 regarded as borer free in the spring, and will become infested during 

 the following summer from outside sources, probably to a degree 

 depending upon the severity of infestation in the surrounding terri- 

 tory. 



The fact that the most evident borer injury occurs in the lower 

 half of the stalk in stubble cane makes the damage greater than in 

 plant cane forseveral reasons. The first is that the actual mechanical 

 injury by the borer is in the lower joints, which are more mature 

 and have the greater sugar content. Again, the presence of the borer 

 burrows and tunnels in the lower joints affects the flow of sap to the 

 top of the cane, thus interfering, more or less, with the growth of the 

 whole cane. Also, the joints near the base of the plant tend to 

 become hard and woody following borer attack, thus increasing the 

 percentage of fiber and decreasing the percentage of juice. Inciden- 

 tally the latter point increases the difficulty of grinding, as was called 

 to the attention of the writer by a sugar-house manager attributing 

 the breaking of some machinery to the crushing of heavily infested 

 sugar cane. 



EFFECT OF INFESTATION UPON THE WEIGHT OF CANE. 



In order to find out the effect of borer infestation upon the weight 

 of cane, 100 stalks were picked out and carefully averaged in size. 

 All were cut off the same length. No attention was paid to borer 

 infestation in selecting the canes, and the opinions of several gentle- 

 men were consulted, all canes larger or smaller than the average 

 being thrown out and replaced by others until on examination it 

 was impossible to select canes larger or smaller than the others. 



