MONTHLY NOTES ON GRUBS AND OTHER CANE PESTS. 13 
practically all the Goru died out, while the D1135 is doing very well. 
Undoubtedly, this result is due to the different character of the roots of 
the two cane varieties. 
In ratooning during dry weather Goru often succumbs, while under 
moist conditions it usually does well. I believe that this is due to the 
fact that the main roots, which are lateral, are broken off in ploughing, 
and the stool dries out. This supposition is borne out by the fact that 
Goru, which was not ploughed, on the same farm is growing well. 
Again, referring to the ratooning qualities of D1135, Mr. P. Wienert 
showed me one of his fields at Fishery Creek, which was planted with 
Badila in 1916, and the misses, which were abundant, were supplied with 
D1135. At the time of my recent visit, practically all of the Badila had 
been killed by the borer-beetle, while the shoots of D1135 were very 
conspicuous because of their great vigour, and had not suffered in the 
least from the pest. 
PARASITES OF THE BORER-BEETLE. 
The tachinid parasite (Ceromasia sphenophori), referred to in my 
recent reports, have emerged splendidly in our cage at Gordonvale, where 
they have had our close attention; but those placed at Babinda and 
Moolaba have not fared so well. On two occasions we found that ants 
(Pheidole megacephala) had got into the boxes of cane and were making 
their nests in the channels of the borers. We have no way of knowing, 
in these cases, whether the flies have escaped safely or not, and must 
wait for some months to see if they become established in those districts. 
We feel rather confident of the result in our own district, because 
the flies were liberated from day to day, after they had mated in the 
large cage; and we sometimes saw them flying about in the borer-infested 
cane, which is alongside. They will have a good chance in this field, for 
it is not to be cut until the end of the season, and there is plenty of other 
cane near by. 
BORER-BEETLES, Rats, AND OwWLs. 
Let me call attention to the close relation existing between borer 
beetles and cane rats; and, further on, the value of barn owls in 
destroying these rodents. 
It is a recognised fact that the borer-beetles work along the lines 
of least resistance in depositing their eggs. If they find a split or hole 
in the rind of the cane they take advantage of it; for they are able to 
deposit their eggs more abundantly. The stalks chewed by rats are 
ideal locations for finding the young grubs of the borer, and for this 
reason I would urge that these should be discarded when cutting cane 
plants. 
Let us recognise, then, that the destruction of the cane rat is an 
important step in the control of the borer-beetle, where soft varieties 
are grown. And, again, that rats are more abundant in badly cultivated 
fields, especially those with weedy headlands. I think this may be 
