454 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 12 



increasing the vigour of the crop, and in this way making the plants 

 more resistant to attack. However, as I shall indicate later, I have 

 found that it often has a more direct action in the destruction of the 

 pest. 



Undoubtedly the value of cultivation is recognized; but on many 

 farms it is not carried out. Climatic conditions bring about great 

 difficulties, in this regard, particularly with the late-planted crop. 

 Many soils can not be worked properly when either too wet or too dry, 

 and as a consequence the cane is left to suffer. However, it is common 

 experience that the man who cultivates well is the man who reaps the 

 reward. 



I have found bj^ extensive experiments at Greenhills, during the 

 past season, that both the eggs and the young grubs are considerably 

 injured by even shallow cultivation, for they are located near the sur- 

 face in December. The common cultivators, reaching to a depth 

 of about six inches, are satisfactory for this work; though I got some- 

 what better results by using a pony-plow, which got in closer to the 

 roots. 



In order to be effective this work must start at the time the beetles 

 begin to emerge, and be continued, going over the ground every fort- 

 night while they are on the wing. Normally, this would mean about 

 four cultivations, which would mean no extra work in the case of late 

 cane. I have advocated September-October planting on grubby- 

 soils, where they are well drained, so as to facilitate this cultivation 

 during the flight of the beetles; the plants are then small enough so 

 that the implements can get well under them. 



We have had encouraging results in the use of arsenic for the de- 

 struction of the grubs. I found that by using arsenious acid (white 

 arsenic) with Greenhill's soil in pots, that full grown grubs were 

 quickly destroyed by ingesting it, — all of them dying in one to four 

 days. The quantity used was approximately what would amount to 

 about 20 pounds per acre. I should state that only sifted soil and 

 arsenic were placed in the pots, so that it was demonstrated that the 

 grubs were destroyed by feeding on the poisoned humus of the soil. 



Arsenic was used on our experimental plots at Meringa, in varying 

 proportions and combinations; the best results apparently being from 

 the use of the poison placed in the drill with the plants. In this 

 case 20 pounds was mixed with 5 cwt. of meatworks manure per acre. 

 The cane came along splendidly, with no sign of grub-injury, while 

 several of the other plots showed more or less infestation. 



Apparently the most satisfactory and far-reaching remedy, however, 

 is the removal of all feeding trees, within a radius of about half a mile 

 of infested cane areas. Investigation has demonstrated that once 



