MONTHLY NOTES ON GEUBS AND OTHEE CANE PESTS. 9 



Iseetles. Where a large field of trash is to be burnt at this time, it would 

 be well to conserve it by separating it into small blocks, and burn a 

 little each evening. It may be profitable to save up rubbish of all kinds 

 for fires at this time. 



Lepidiota Frenchi at Meringa. 



This grass-feeding species, recently described in detail by Mr. 

 Jarvis, is becoming a serious pest of sugar-cane at Meringa. In one 

 field of first ratoons, the grubs have gradually worked back from the 

 grassy roadside, completely destroying patches of the cane, by eating 

 off all the roots. In digging up the dying stools we found from six 

 to ten large third-stage grubs of this species. These same grubs, in their 

 younger stages, did considerable damage to the plant-cane last year, 

 and now in their final stage they are cleaning up some of the ratoons 

 entirely. The owner of this field is treating the infested area, at our 

 suggestion, with carbon bisulphide, in the hope of destroying these 

 centres of infestation, which are evidently spreading to the surrounding 

 healthy cane. The grubs, if left alone, would feed for several months 

 yet, and emerge as beetles next year, since they have a two-year life 

 cycle. Large grubs ploughed up at this season, in grass-land, are very 

 apt to belong to this species, for all grubs of the common grey-back 

 cockchafer changed to beetles, far below the reach of the plough, several 

 months ago. 



Experimental Plots. 



There is an excellent crop of cane on the half-acre plot, treated 

 with arsenic last season, by Mr. Jai'vis. Unfortunately, the experi- 

 ment is not conclusive, because the owner treated the surrounding cane 

 with carbon bisulphide, without leaving the necessary check-plots. 

 However, though the grubs were evidently not very bad in this locality 

 last season, a few untreated rows left at the far end of the field became 

 somewhat infested, so that a part of the cane fell over. Walking through 

 the field, it is evident that the part treated with arsenic is just as vigor- 

 ous as that treated with carbon bisulphide, and certainly the cost of 

 the arsenic is considerably less. 



Our 10-acre block at Meringa has all of the Aveedy-trash ploughed 

 in, and a part of it is covered with a heavy growth of Mauritius bean. 

 Since we were unable to get labour to put this land in shape for October 

 planting, we are now plaiming to leave the part covered with bean and 

 work the balance through the flight of the beetles, getting all of the 

 fifteen plots ready for March planting. 



Mr. Warner's co-operation with our Department at Greenhills is 

 going to be a mutual benefit. We shall have about a dozen plots, of 

 an acre or more each, demonstrating principally cultural methods and 

 the effects of poisons, fertilisers, &e. 



