42 MONTHLY NOTES ON GRUBS AND OTHER CANE PESTS. 
roots beginning to shoot out: Apparently the grubs reached their zenith 
about the middle of April, in this district, and they have now (10th May) 
almost all gone down. 
Mossman DIstTrRICT. 
During the month I made a careful survey of the grub situation in 
the Mossman district, a region which had been of special interest to me 
because of the remarkable way the grub-pest disappeared there. In 
former reports I have noted my observations on the emergence of the 
cane-beetles, which were rather numerous last December, and I was 
therefore agreeably surprised to find little evident injury from grubs 
this season at Mossman. 
I can only assign this immunity to two important factors :—Late 
cultivation, and the use of ammonium sulphate. This chemical is used 
rather generally throughout the district. The season, too, has been 
particularly favourable for late cultivation, and I found absolutely no 
injury to the late-planted cane. The only places where the grubs got 
in their work, were in the ratoons and early-plant crops, which had been 
laid by before the beetles flew. An interesting example of this was on 
the farm of Crees Brothers. A field of 134 acres of Badila was planted 
in June, 1918, on rich sandy-loam soil. Only about half of it was 
cultivated during the flight of the beetles in December; the other half 
was not worked at that time because of the difficulty in getting through 
it. The crop is most remarkable, for the portion which did not get the 
final cultivation has suffered considerably from grubs, while the worked 
half is uninjured. The land was fallow for twelve months before 
planting, because a crop had failed to strike. At the time of my visit 
the late-cultivated portion was a beautiful dark-green, with stalks of 
5 or 6 feet in length. Mr. Crees informed me that no manure was applied. 
One could not find a better example of the value of cultivation in the 
control of grubs. 
The late-planted Badila in an adjoining block on this farm gave no 
indications of grubs. It is about 10 feet high, and could not look finer. 
About a bag of ammonia was used to the acre, after the rains began, and 
cultivation was continued right through the flight of the beetles. 
This farm formerly belonged to Mr. F. W. Barnard, who had serious 
losses from grubs in the early days. He became an advocate of the use 
of carbon bisulphide, and I found that he recognised the value of late 
cultivation. He wrote:* ‘‘Farmers in this district, on land subject to 
grubs, have found that by planting not earlier than September the cane 
is young and growing vigorously at the time the grubs are about. The 
plant is then continually throwing out fresh rootlets, which enables it to 
withstand, to a certain extent, the onslaught of the pest. Also, at the time 
the beetles lay their eggs cultivators are being freely used, which destroys 
large numbers of them.’’ 
tae See Australian Sugar Journal,’’ Vol. 1, Dp. 481, 
