SCIENCE AND INDUSTRY. 
The Chalcid Parasites of Muscid Flies in 
Australia.” 
By T. HARVEY JOHNSTON, M.A., D.Sc., Professor of Biology, University, Brisbane. 
On account of the economic importance of Muscid flies—a group 
which includes not only the house fly or typhoid fly, but also most of 
the various sheep-maggot flies, or blowflies, as well as the common “ bush 
flies” of Australia—considerable attention has been given to the study 
of their hymenopterous parasites, at least one of which has been utilized 
in New South Wales and Queensland as un agent to assist in controlling 
the spread of these Diptera. It has also been suggested to the Federal 
authorities by an eminent British entomologist that a number of species 
might, with advantage, be introduced from England to ‘assist in this 
work. ; 
Mr. W. W. Froggatt has done a considerable amount of work on fly 
parasites, having dealt with not less than three, viz., Nasonia brevicornis, 
Chalcis calliphore, and Dirrhinus sarcophage, which destroy pupe of 
one or more of the sheep-maggot flies. 
In this article it is proposed (1) to record observations on two 
species, one of which is now reported for the first time as occurring in 
Australia; (2) to briefly review the work on the parasites recorded as 
being already present in the continent; and (3) to discuss the suggestion 
that certain other wasps might be profitably introduced. 
The following: five muscid-destroying chalcids are now known {o 
occur in Eastern Australia:—(1) Spalangia muscidarum; (2) Nasonia 
brevicornis; (3) Chaleis calliphore; (4) Dirrhinus sarcophage ; (5) 
Pachycrepoideus dubius., The first, second, and fifth belong to the 
Pteromalide, and to the sub-families Spalangiine, Pteromaline, and 
Sphegigasterinx respectively, while the others are members of the Chal- 
cidide. The first, second, and fifth are known from Queensland; the 
second, third, fourth, and perhaps also the first from New South 
Wales. 
(1) Spalangia muscidarum (Richardson). 
During November and December, 1919, when numbers of house flies 
as well as certain species of bush flies were being raised in the laboratory 
at Eidsvold, Burnett River, Queensland, in connexion with work on 
flies as transmitters of worm parasites of stock, it was noticed that 
in several, batches the percentage of flies emerging was very low, viz., 
from 15 per cent. to 61 per cent. Thus, in one experiment with house 
flies, the larvee pupated on 21st November, and a few flies emerged on 
29th and 30th November. No more having emerged after the lapse of 
over a week, the pupe were collected and counted, when it was found 
* Abstract of a paper by Dr. Johnston and Miss Bancroft, published by the Royal Society of 
Queensland, 1920. 
308 
