A COKySIDEHATTOX OF THE IXSFCT POPULATIOX ASSOCIATED 
WITH Cow Duxg at CkawleYj W.A. 
237 
other material. Where M. domestica is found breeding in cow dung, the 
material is generally mixed with straw or some such substance (Austen, 1928. 
Results quoted by Thomsen & Hammer). 
Musca vetustissima. Walker. 
This is the common bush fly which annoys workers in the open because 
of its habit of clustering on the face and attacking the eyes. Its activities 
have earned it the title of the Queensland cattle fly and it also pesters 
horses. It is of some economic importance because it transmits Habronema 
muscae, a Nematode parasite in the stomach of the horse and another unde- 
termined species of Habronema which causes habronemic conjunctivitis of 
horses (Johnston & Bancroft, 1920). It is probably capable of setting up 
Anthrax infection under some circumstances (Cleland, 1913). The life history 
has been described by Johnston &■ Bancroft (1919), the breeding medium 
being either horse or cow dung. The total period of development from the 
egg to the adult in the Eidsvald district of Queensland was found to be 10 to 
14 days in November. 
At Crawley the flies are numerous on fresh dungs although only six speci- 
mens have actually been reared from dung in May, 1941, In January, 1942, 
large numbers were reared from cow dung from Dog Swamp, Tuart Hill W.A., 
which also contained maggots of Sarcophaga {Parasarcophaga) depressa, Des- 
voidy. 
Sub-Family 3 ; ANTHOMYIINAE. 
Hylemyia deceptiva, Mall. 
A single specimen of this species or near to it was bred out from cow dung 
in September, 1941. H. deceptiva is recorded on carrion at Canberra (Fuller, 
1934). Another undetermined species of Hyl&myia was bred from second stage 
cow dung in June, 1941. 
H. variata Fallen and H. strigosa Fallen, which occur in Ayrshire and 
Arran in West Scotland are ovoviviparous flies. Whether this is the case with 
the local species is as yet unknown. 
Sub-Family 4 • PHAONIINAE, 
Rhynchomydaea (Hardyia) carinata, Stein. 
Flies near this species are the commonest of the large Muscids frequenting 
cow dung at Crawley. The adults, which feed on fresh dung, occur during the 
period May to November, while specimens have been bred out from cow dung 
in the period March to Noveml^er. The species is present at Katanning. 
Eggs are laid singly ^vith the anterior ends projecting in fresh dung. 
About 14 larvae is the maximum number wliich mature in each cake. They 
occur in first to third stage dung, the larvae period being about 14 days. The 
larvae are coprophagus. 
Pupation occurs in the dung, usually in a hollowed cavity on the lower 
or near the upper surface. Sometimes, after heavy rain, puparia may be 
found on top of cakes in shaded situations. The pupal stage lasts about three 
weeks. The total cycle from egg to emergence of the adult took 34 days in 
September (average temperature 13*9° C.) and October (16*1° C.), 1941. 
