A Consideration of the Insect Population Associated 
WITH Cow Dung at Crawley, W.A. 
233 : 
At Crawley specimen of ? Rhegmoclema sp. emerged in large numbers 
in the period November, 1940, to April, 1941, from dung brought into the 
laboratory in November, 1940. In April, 1941, another batch came out of 
39-day-old dung which also contained Scarab larvae. They have not been 
seen in the field and consequently have no place in the succession in cow dung- 
outdoors. 
They appear to breed only in late fourth and such fifth stage dungs as 
remain moist. Both the larva (PI. 1, Fig. 7) and the pupa (PL 1, Fig. 8) show 
adaptations for living in poorly aerated, moist surrounding. Pupation occurs 
inside the last larvae skin. 
A number of adults dissected in February and March, 1941, contained 
as many as six to eight nematodes, each in the abdominal region. The para- 
sites must have occupied the greater part of the space of the abdomen. 
F. 4. MYCETOPHILIDAE. 
A single specimen of ? Mycetophila was obtained as a pupa from fifth 
stage dung in the laboratory. Unlike the Sciarid pupa this was suspended 
in a diffuse cocoon of white threads. The family is of no importance in the 
succession. 
F. 5, TIPULIDAE. 
Two Eriopterine flies were obtained in July, 1941, from artificially- 
moistened fifth stage cow dung. According to Imms (1938) the larvae may 
occur in damp situations among grass, roots, decaying vegetation, or may 
be aquatic. No sign of them in the field was seen. 
F. 6. STRATIOMYIDAE. 
While the adults of this family are mostly flower feeders, the larvae occur 
in diverse habitata such as water, soil, and rotting wood (Imms, 1938). The 
larvae of Myiochrysa have been found in cow dung (Williston, 1908). Actinia 
incisuralis, Macq. is found near carrion (Fuller, 1934). 
At Crawley, Neoexaireta spinigera, Wied. was seen to lay clutches of 
eggs on fresh cow dung in the laboratory in May and June, 1941. These 
hatched within three days, but the larvae failed to complete their develop- 
ment. Other larvae collected on 7th November, 1940, which probably be- 
longed to this species, reached the pupal period by 10th April, 1941, but no 
adults emerged. 
Stratiomyid larvae occur occasionally at Crawley in cow dung in the 
field, although more numerous in rotting vegetation. These larvae, in the 
course of their relatively long lives, must tolerate the change in condition 
of the dung from fresh to old and dry, whereas in other dung-breeding insects 
the larvae are generally restricted to the one stage or to stages which show 
no marked differences. 
F. 7. DOLICHOPODIDAE. 
A number of black x)redaceous flies, near Asyyidetus sp., occur during 
autumn and winter on fresh cow dung, preying on the Borborids attracted 
to it. 
F. 8. PHORIDAE. 
Flies near Chaetocnemistoptera in Curran’s Key to the North American 
genera (Curran, 1934) are frequently attracted to cow dung in the laboratory. 
The relationship of carrion to cow dung insects holds good as Sciadocera 
rufomaculata, WJiite, and Beckerma sp. are members of the carrion association 
at Canberra (Fuller, 1934). 
