14 MONTHLY NOTES ON GRUBS AND OTHER CANE PESTS. 
accounted for by the fact that owls are unable to catch the rodents 
thus protected. When the headlands are clean the birds are able to 
discover their prey as the rats cross from one field to another. 
My experience with the American barn owl (Strix practincola) will 
be of interest to those suffering from a pest of rats. 
A pair of these birds had been nesting for some time on the top of 
a large, unused chimney of a school building. Upon examination I found 
that the chimney was almost filled with the east-up pellets of the birds. 
Every bird student knows how the owl regurgitates the bones, hair, and 
so forth in a little pellet shortly after each meal; after raking these out 
of the chimney they almost filled a 2-bushel bag; and each one repre- 
sented a rodent, identified by the skull, which was entire. I took the 
exhibit to a farmers’ club, where it stirred up great enthusiasm for the 
protection of the owls. 
I was pleased to learn from the literature here that Australia has 
four species of barn owls, and that one (Strix delicatula) was said to be 
common in North Queensland. Investigating the matter in the vicinity 
of the laboratory, at night, I soon discovered a pair with several full- 
grown young. These birds have a eall which is not unlike that of our 
American species. I can best imitate it by forcibly exhaling the breath 
between the tongue and teeth, making a sort of rasping sound. These 
owls are very friendly and come around the buildings at night, even 
perching on the water tank at the house when I imitated their eall. 
This immediate region does not suffer from cane rats, and I do not 
doubt that these birds are doing their part to hold them in check. 
Morn PEsts. 
Both the army worm (Cirphis unipuncta) and the noctuid moth- 
borer (Phragmatiphila truncata) are rather troublesome this season in 
places along the Mulgrave River. Fortunately, both species are attacked 
freely by parasites, which keep them from becoming serious pests. 
Every grower is familiar with the work of the army worm on young 
cance plants, the leaves being chipped out at the edges; and the caterpillar 
is usually to be found during the day hiding between the top leaves. 
The work of the noctuid moth-borer, though less familiar, is easily 
recognised on young canes, for the central leaves are usually killed, as all 
the feeding is being done inside the shoot. On old cane the eaterpillars 
work behind the upper leaf-sheaths, boring into the stalks here and there. 
Their work may be easily recognised by the abundant frass they throw 
out. 
The caterpillars do not remain long inside the stalk, for a single 
individual may make a number of tunnels, evidently only going into 
them to feed, and to hide during the day. The principal damage to 
mature cane is that the caterpillars cause it to shoot freely at the eyes, 
due to the injury of the terminal bud. 
