THE SUGAR-CANE MOTH BORER. 6 



plants per acre may be destroyed, but so many plants remain in the 

 field that this loss is not great. It should be prevented, however, 

 because it is on these young plants that the borers multiply in suffi- 

 cient numbers to become a serious menace to larger canes. 



Under calculable losses the injury to mature cane alone will be 

 considered. The full amount of injury is shown only by chemical 

 analysis. Infested and' uninfested cane from Texas, not affected by 

 red rot, a disease which often follows borer damage, was analyzed, 

 with the following results : 



Uninfested. 



Per cent. 



Brix J ■ 19. 5 



Sucrose 17. 45 



Purity 89. 5 



Infested. 



Per cent. 

 Brix 17. 55 



Sucrose 15. 1 



Purity : 86. 



Dr. William E. Cross, at that time of the Sugar Experiment Sta- 

 tion, New Orleans, La., who made the analyses, stated that the loss 

 due to the moth borer was about 20 per cent of the sugar — a greater 

 loss than might be expected from the figures. Mr. John Allbright, 

 chief of the laboratory at Central Chaparra, Cuba, analyzed infested 

 and uninfested cane from a field at that central factory. The results 

 follow : 



Uninfested. 



Per cent. 



Brix . 21.3 



Sucrose 19. 9 



Purity 93. 4 



Extraction 47. 2 



Infested. 



Per cent. 



Brix L 18. 8 



Sucrose 16. 85 



Purity 89. 6 



Extraction 36. 4 



Loss in sucrose, 3.3 per cent in cane. 

 Loss in sucrose, 15.3 per cent in juice. 



Messrs. D. L. Van Dine (169) x and T. C. Barber (14) have in- 

 vestigated the losses due to the moth borer in considerable detail. 

 Mr. Barber sums up the effect on sugar content in Table I. 



Table I.- 



-Analysis of sugar cane (D. 74) to determine effect on sugar con- 

 tent of the borer injury to cane. 



03 



Nature of 



a 



03 



o 



o 



I 

 o 



o 

 ■+j ■ 



S O 



IB 



CO 



o o 



■d 



d 



CD 



g 



u 

 cS 



bo . 

 . 

 CO CD 



§1 



p 



1 



CD 

 g U 





+^ ■ 



•r-i t- 

 U CD 



ftg 



o 



sample. 



+3 



+3 



s 



"1 



o 



C0 4^> 



o 



o 



.S3 *-> 



" CD 

 CO O O 



o m& 



CO 



O 

 O 



3 



CD 

 CO 

 O 

 O 







CD 

 O 

 CD 







fl o 



'A 





Ph 



l-l 



EH 



^ 



O 



CQ 



C5 



m 



^ 



Ph 



Hi 







Gms. 



Oms. 





p. a. 



P.ct. 



P.ct. 



P.ct. 



P.ct. 



P.ct. 



P.ct. 



P.ct. 



P.ct. 



P.fitf. 



1 



Borer-free 



9,990 



6,108 



61.1 





17.1 





1.6 



1.1 



11.1 



14.4 





84.2 





2 



Medium infested 



11, 081 



6,735 



60.8 



0.3 



16.1 



1.0 



1.7 



1.2 



12.9 



13.2 



1.2 



82.0 



2.2 



3 



Heavily infested 



8,824 



5,190 



58.8 



2.3 



13.7 



3.4 



2.1 



1.8 



21.4 



9.8 



4.6 



71.5 



12.7 



Note. — Each sample consisted of 10 canes. Each of the medium-infested canes contained from one to 

 three infested joints, and each of the heavily infested canes five or more infested joints. Analysis made 

 Nov. 12, 1910. 



1 Figures in parentheses refer to entries in the bibliography, pages 63-74. 



