A Consideration of the Insect Population Associated 
wiTPi Cow Dung at Crawley, W.A. 
219 
12.— A CONSIDERATION OF THE INSECT 
POPULATION ASSOCIATED WITH COW 
DUNG AT CRAWLEY, W.A. 
BY G. J. Snowball, B.Sc. (Hons.)* 
Read 9th June, 1942 ; Published 28th March, 1944. 
1. INTRODUCTION. 
The research w^ork described in this paper is an attempt to indicate the 
main insects which form the population of cow dung at Crawley and to assign 
them to their proper place in the ecology of that substance. Most of the 
work was performed at the Biology Department, Crawley, during the periods 
February to November, 1940, and February, 1941, to February, 1942. Two 
cows supplied most of the dung utilised, but supporting observations at May- 
lands and Spearwood showed that this restricted amount of material indicated 
correctly the qualitative nature of the population, a conclusion borne out by 
the study of insects in tlie dung dropped by a herd of fifteen cow's grazing 
in the grounds of the University. The writer also had tlie opportunity of 
examining cow dung from Armadale, and in August, 1941, was able to pay 
a visit to Katanning to make a rapid comparative sur\-ey of the cow dung 
pojoulation. 
Katanning (latitude 33° 38^ S., longitude 117° 35^ F.) has a climate 
of the continental type, characterised by a considerable \-ariation between 
maximum and minimum temperatures. Perth (latitude 31° 52' W, longitude 
110° 3' F.) has a Mediterranean climate with less difference between the ex- 
tremes of temperature. The rainfall at Katanning, although annually amount- 
ing to only about half that at Pei'th, is much more evenlv distributed through- 
out the year, rainfall at Perth being essentially of the winter type. 
Table 1 . 
The mean daily maximum and minimum temperatures, the mean daily 
relative humidity, and the mean annual rainfall at Katanning and Perth, 
Western Australia, for 34 years prior to 1932 (based on figures from the 
Weather Bureau, Perth) :■ — 
PERTH. 
katanning 
Maximum ° C. 
22-89 
21-94 
Minimum ° C. 
12-89 
9-11 
Humidity 
03 
70 
Rainfall (inches) 
34-7 
18-7 
2. MFTHODS, 
No accurate t[uantitative work was attempted in tins general approach 
to the problem. The insects found in various cow dungs were submitted to 
experts for identitication where possible and obsc'r\ations made on their 
habits. Portions of cow dung containing immature stages were brought 
into tlie laboratory for study of jihases of the life histories of the insects con- 
cerned. 
3. SUCCFSSION. 
A large numlier of insect species are associated with faecal matter, 
cs])ecially with that of mammals, which is usually of sufficient ({uantity to 
form an ecological habitat of some duration. 
*In 1941 tlie writer was the recipient of a Ilackett Scholarship, and in 194 ^ of a 
Hackett Studentshij>, for which his grateful thanks are due to the University of W.a" 
