67 



through the soil from one stool of canes to another, and 

 they have been found several inches below the roots of the 



Fig-. 71. Eggs of root borer of sugar-cane. 



Enlarged. ( Original. ) 



cane, in the soil. The life-cycle of this insect occupies 

 about a year, of which about 10 days are spent in the egg 

 stage, some 300 in the larval stage (Fig. 73), 15 in the 

 pupal and about 20 in the adult, during which latter 



period matingand egg-laying 

 take place. The adult is a 

 large weevil, about j-inch in 

 length, pale-green in colour, 

 with dark, bronze stripes 

 running longitudinally on 

 the wing covers. 



Control. No satisfactory 

 method of control has been 

 found. It has been noted on 

 one estate, at least, that 

 where canes follow canes in 

 the same fields in the same 

 year, the attacks of root 

 borer are much worse than 

 in fields that have been 

 rested ; that is, fields that 

 have not been returned to 

 canes for eighteen months or 

 more'after reaping, either with or without an intermediate 

 crop." It seems likely that careful investigation will reveal 

 points in the life-history of this insect which are 

 considerably different from those supposed in our present 

 knowledge, especially as to the length of life in the larval 

 condition. The present recommendations are that in 



Fig. 72. Root borer. 

 Tunnels in cane made by the grub. 

 Eeduced. (Original.) 



