MONTHLY NOTES ON GEUBS AND OTHER CANE PESTS. 19 



important with regard to our experiments was the upsetting of the 

 Insectary, with its numerous pots and cages of parasites. Practically 

 .all of the cane of the district has been flattened out, though little appears 

 to be uprooted. 



Grub-devastation Appeared very Early. 

 Hardly had we sent away our last monthly report when the devastat- 

 ing effects of the grubs began to appear by leaps and bounds. As usual, 

 Greenhills Estate was among the first to suffer. Large areas turned 

 brown within a week, the leaves drying up as if a fire had been through 

 Ihe field. Both plant and ratoon cane appears to suffer equally if 

 located within the infested area. 



As we pointed out in last report, the worst infestation is in fields 

 lying near the timber bordering this estate; this fact is all the more 

 evident now that the cane of the diseased areas has changed colour. It 

 would be a tremendous undertaking to remove all this timber, but it 

 would probably pay to go through and kill all the feeding trees of the 

 beetles for at least half a mile back. This could be done rather reason- 

 ably and effectively with arsenic. Of course, these remarks would apply 

 equally to any field suffering under similar conditions. 



It is a curious fact that infested fields remain infested year after 

 year, though the beetles have a one-year life cycle. Evidently they go 

 back to oviposit in the same fields in which they emerged, simply because 

 these fields are most convenient to their feeding trees. They could hardly 

 be credited with a memory of their natal spot after their feeding period 

 of about two weeks. The fact, too, that grubs disappear, in many 

 instances, from localities after the adjoining timber is removed would 

 seem conclusive evidence. 



Introduction of New Parasites. 



The tremendous importance of the problem has never appeared 

 -greater than now, as we see hundreds of acres of beautiful cane going 

 down to destruction before the grubs ; this, too, after all the money has 

 been spent upon it to get it to a size where it would require no further 

 work. It certainly behoves us to leave no stone unturned for the control 

 of such a pest. 



In a region like Hawaii, the natural impulse is to seek the assistance 

 of parasites, under similar conditions, because parasites have been 

 demonstrated to be the most effective means of control. The Planters' 

 Association of Hawaii have spent many thousands of dollars in the search 

 for, and introduction of, these friendly insects; but this work has been 

 worth millions to them. It has spelled the difference between absolute 

 failure and success. The story of the trials and hardships of their 



