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COMBATING THE BLOW-FLY. 
Combating the Blow-fly. 
New Treatment Recommended. 
The blow-fly pest has long since become a source of serious trouble 
to the sheep industry in Australia, and annually involves pastoralists 
in heavy losses. In some years the mortality amongst sheep is much 
greater than in others, due largely to more favorable weather conditions 
for the breeding of the flies. The Institute of Science and Industry is 
co-operating with the Governments of Queensland and of New South 
Wales in carrying out investigations into methods of minimizing the 
effects of the pest, and a Committee was appointed in each State to 
supervise and direct the work. The practical effect of Chalcid. wasps, 
which have been found to destroy the larve of the flies, is being 
thoroughly tested, and wasps are being bred in large numbers. Other 
lines of investigation are also being followed up, and at Roma (Queens- 
land) highly encouraging results have been obtained from the “ jetting ” 
of the sheep with a dip containing 0.2 of arsenious oxide in solution. | 
Upon this phase of the work, Messrs. W. A. Russell, owner of Dalmally 
Station, Roma, where the experiments are being carried out, and Mr. 
W. G. Brown, sheep expert of the Queensland Department of Agricul- 
ture, and a member of the special committee appointed by the Institute, 
have submitted the following report :— 
The experiments conducted by the Institute of Science and 
Industry at Dalmally, Roma, have now been in operation for 
eighteen months, and sufficiently good results have been obtained 
to warrant a progress report. These results show that much relief 
can be obtained by pastoralists by a few comparatively nile and 
inexpensive operations. 
The work done enables three general statements now to be made :— 
(1) No specific yet tried completely prevents fly attack. 
(2) No specifie has given good protection for more than three 
months. 
: (8) The use of arsenical preparations has given the most 
successful results. 
Other questions which require much further investigation are :— 
(a) The determination of the range of flies from their breeding 
place. There is some evidence that they do not as a 
rule travel any great distance. Should this prove to be 
generally correct, it will be an exceedingly important 
factor in determining the amount of surrounding clear 
area necessary for protecting flocks. Much | work 
requires to be done ere the general range of the flies has 
been determined. 
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