A Consideration op the Insect Population Associated 
WITH Cow Dung at Crawley^ W.A. 
227 
Cryptobium elegans, BJkb. 
This species is associated with L. socius^ but nothing of its life history is 
known. The genus is represented by 20 species in England, 19 of which 
live in dung and similar material (Stephens, 1839). 
Oxytelus, sp. 
Several unidentified species are numerous in cow dung, sometimes greatly 
exceeding Leptacinus and Cryptobium in numbers. They are among the 
first to colonise freshly dropped dung, especially if it has been scattered in 
a number of shallow pieces. They also occur in numbers in carrion. In 
northern Australia they may play a part in reducing the incidence of the 
Buffalo Fly (Lyperosia exigua, de Meij) by competing with its larvae in cow 
dung (Mackerass, 1932). 
The only immature stage seen was a single exarate piipa in September, 
1941, in the sand under dung, three months old, kept in the laboratory since 
dropping. 
F. 4. SILPHIDAE. 
Only two specimens, probably belonging to Choleva sp., were collected 
from third stage cow dung at Crawley in March, 1941, and hence the family 
is unimportant in the succession. Two species of Choleva occur in carrion 
(Fuller, 1934). 
F. 5. TRICHOPTERYGIDAE. 
At Crawley, species near Epoptia and Philagarica in cow dung in all 
stages, especially in the fourth if it is not too dry. Their habits are not kno\vn. 
The family is best represented in the tropics, occurring in rubbish, leaves,, 
under bark or in rotten wood (Lefroy, 1923). 
F. 6 . HISTERIDAE. 
Members of this family are present in cow dung at Crawley between 
October and May, although they are found in carrion and decaying grass at 
other seasons of the year. 
SAPRINUS. 
Two species of this genus occur in cow dung of which only one, S. incisus 
Er., has been identified. Both exhibit a preference for fresh cow dung and 
tolerate excess moisture better than do the Hydrophilids. 
They never remain in the dung beyond the third stage, which is the one 
containing the majority of their prey, larvae of Sepsids, Drosophilids, and 
probably Borborids. Small quantities of dung are also eaten. Three larvae 
were found in fourth stage dung brought from Armadale to St. George’s Col- 
lege in March, 1941. One of those subsequently pupated ; the adult emerging 
after three wrecks at an average temperature of 18° C. 
The genus Saprinus, like other insects in decaying materials, is widespread. 
Species of it occur in England (Stephens, 1839), New' Zealand (Broun, 1880), 
and in carrion at Canberra (Fuller, 1934). 
PLATYSOMA. 
One specimen of P. ? nmltistriatmv , Lea, w'as collected in second stage 
cow dung on 4th March, 1941. Stephens (1839) describes three species in 
England all under bark. 
