G. J. Snowball. 
2:U) 
larvae up to a foot from its starting point. These acrobatics are similar to 
those performed by the larvae of Piophila casei, the so-called “ Cheese 
Skippers.” Continuous stimulation will cause a larva to repeat these move- 
ments until it can no longer lift itself from the ground. 
Pupation occurs in the dimg, the puparium being reddish-brown in colour. 
ISTo exact figures of the length of life history are available. Larvae of imknown 
age collected on 3rd April, 1941, had all given rise to adult flies by 30th May, 
so that in some cases the life history requires more than 58 days, longer than 
that of dung-breeding Muscids. 
F. 13. CALLIPHORIDAE. 
Sub-Family 1 : CALLIPHORINAE. 
Calliphora (Neopollenia) australis, Boisd., Calliphora (Proeclcon) nociva. 
Hardy, and Lucilia cuprina, Wied., all visit fresh cow dung in spring and au- 
tumn, though never in large numbers. Attracted by the odour, the adults 
suck up the liquid dung, often in large quantities, but no evidence of their 
breeding in cow” dung at Crawley was obtained. Their association with it 
is thus of a casual nature and can have no effect on the succession. 
Sub-Family 2 ; SARCOPHAGINAE. 
In the period October-Novembcr, 1941, 10 specimens of Sarcophaga (Para- 
sarcophaga) depressa, Desvoidy, were reared in cow dung from Crawley, and 
in January, 1942, 53 from dung obtained at Dog Swamp, W.A. The eggs are 
deposited in fresh dung, especially in strong-stnelling cakes. In spite of 
their large size, 20 to 30 larvae per cake may occur. They generally leave 
the dung to pupate without displaying the same degree of restlessness prior 
to pupation displayed by the larvae of Calliphora stygia. The cakes which 
sheltered the larvae contained normal populations of other insects. 
S. varia Walk, normally breeds in cow dung in New Zealand. Two species 
of Sarcophaga frequent carrion at Canberra (Fuller, 1934), while various species 
of the genus attack living sheep as secondary blowflies in the tropical and 
sub-tropical parts of Northern Australia (C.S.I.R., 1933). 
F. 14. MUSCIDAE. 
Sub-Family 1 : FANNIINAE. 
? Fannia ^p. 
One fly probably belonging to this genus was bred from cow dung in the 
laboratory at Crawley. The eggs were laid on 16th September, 1941, hatching 
about eight days later into “hairy ” maggots. These remained on the sur- 
face of the dung without penetrating it until 20th October, when four pupated. 
The only fly which emerged at all did so on 2nd November. 
In the field, eggs are common and larvae have been seen on two occasions, 
having actually penetrated into third stage dung but no adults have been bred 
out. 
Sub-Family 2 : MUSCINAE, 
Musca domestica, Linn. 
Cow dung has very little attraction for the ovipositing female and this 
fly has not been bred out of it at Crawley. A single puparium, wlaich subse- 
quently gave rise to a female Musca domestica, was fjund in cow dimg from 
Armadale which was of an unusual type, as described in the section on the 
Otitidae, though it contained the usual insect population. The presence of 
the puparium is remarkable, because the dung contained no admixture of any 
