10 MONTHLY NOTES ON GRUBS AND OTHER CANE PESTS, 
I was interested to note the scarcity of natural enemies of the 
tachinid parasites in the district. The exotic ant, Pheidole megacephala, 
which proved such a mortal enemy to the young flies in Fiji, is present, 
but only in moderate numbers. In a few cases I found that these ants 
had cleaned out the borer channels and were living in them, but, as 
mentioned, they are not abundant enough to offer any serious menace to 
the flies. Also, a protracted search among the cane leaves revealed only 
a single jumping spider. These predators are so abundant in Fiji that 
often several are to be seen on a single canestalk. Swallows were rather 
abundant over the field, but I do not consider them a serious enemy to 
the tachinids. 
DISTRIBUTION OF THE PARASITES. 
My original intention was to bring all of the flies to the Mulgrave 
where the borer beetles are proving themselves a serious pest on the 
low-lying lands along the river. Very recently, however, I received a 
letter from the Babinda Association requesting my assistance in the 
placing of some of the parasites there. <A visit to the district proved 
that the pest was very abundant, and particularly so in the region out 
around Moolaba. 
I finally decided to liberate the flies from three centres—Moolaba, 
near the station; Babinda, Dr. Reed’s farm; and at Gordonvale, on 
Mrs. Moller’s farm. A cage has been established at the latter place for 
breeding the flies, which are already emerging in considerable numbers. 
IMPORTANCE OF THE Humus SUPPLY IN THE SOI. 
I have been making further investigations at Hambledon during the 
month. There, certainly, the best system of supplying humus that I have 
seen is in vogue. All of the waste from the mill is composted and left 
for about a year before it is put on the land. 
This compost is made by building up layers of the various refuse 
from the mill, filter-press, trash from the carriers, ashes from wood, 
megass, and so forth. Nothing is permitted to go to waste; even dead 
animals are buried in the pile. 
About thirty loads of this compost, or about 20 tons, are applied to 
the acre. It has proved a very valuable fertiliser, and the cane shows 
a marked increase in growth where it has been applied. There is one 
block near the residence of Mr. A. L. Walker (who, by the way, is a 
grower of keen perception), which is a most excellent experiment. Part 
of this was treated with the compost, leaving the remainder untreated. 
The treated cane is almost a foot taller than the other. 
The soil on this farm scours well, and for this reason it is an easy 
matter to work in trash. Mr. Walker tells me that he leaves the trash 
from the two last ratoon crops, 7.c., volunteering the last ratoons by 
simply relieving over the rows. After the last crop is cut he ploughs 
in this double trash and applies compost, or a green crop, which is 
worked in preparatory to a new series of cane. 
