SCIENCE AND INDUSTRY. - 
The Blow-fly Pest : 
- Scheme of Biological Experimentation. 
Within recent years the study-of the biological control of insect 
pests has made extraordinarily rapid advance, and numerous striking 
instances have been furnished of the complete success of the employ- 
ment of natural enemies for the subjugation of injurious insects. The 
United States, whether because of the magnitude and importance of 
their primary industries, or because of a quicker and clearer appre- 
ciation of the discoveries of biological science, have been more active 
in the application of “natural” methods to pest control than any other 
country. The Bureau of Entomology of the United States of America 
Department of Agriculture and the various State entomological institu-. 
tions have firmly established themselves as essential and powerful 
factors in the development of land industries. 
In Australia, although relatively the problems whose non-solution 
raises a more formidable barrier against economic development and 
industrial expansion than similar difficulties do elsewhere, very little 
work has been done in the direction of ascertaining whether the alliance 
of natural enemies can be secured to combat many of the pests which 
annually reduce the returns from primary industry by hundreds of 
thousands of pounds. 
One of the early acts of the Institute of Science and Industry was 
the investigation into the sheep maggot flies. It is estimated that in 
Queensland alone £1,000,000 a year is lost to the sheep-breeding section 
‘of the pastoral industry by the ravages of blow-flies. In New South 
Wales the pest has increased within the last twenty years to an alarming 
extent, and the loss to that State has reached a huge total. In other 
States the sheep breeder has been put to. great expense in his efforts 
to mitigate or prevent blow-fly infestation, but only with partial 
success, and he is still compelled to ceaselessly wage an unequal war 
against nature. : 
In the work inanguraied by the Institute concurrently with the 
investigation of the efficacy of chemical compounds to prevent sheep 
from becoming attacked, and to minimize the effects of affected sheep, 
has proceeded the study of the natural parasites of the flies. Recent 
conclusions arrived at by Professor T. Harvey Johnston, Professor of 
Biology at the University of Queensland, and Miss Bancroft, and by 
other investigators, regarding the chalcid parasites. of Muscid flies in 
Australia, suggests the probability of very satisfactory results. An 
abstract of the findings of Professor Johnston and Miss Bancroft Was 
published by the Royal Society of Queensland, and appeared in 
Vol. II., No. 5, of Science and Industry. Professor Harvey Johnston, 
who is Scientific Controller of the recently-adopted scheme for the 
Investigation of prickly pear, left Australia a few weeks ago upon a 
visit to the United States, but before his departure he discussed with 
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