Gr. S. GtRAHAM-SmITH 
493 
Species of flies caught in traps. 
Most of the species enumerated in Table III seldom enter houses, 
and under ordinary conditions in this country are of little importance 
as disseminators of disease-producing bacteria. Several of them, 
however, play an important part in spreading disease and causing 
discomfort under war conditions 1 . In this category may be included 
C. erythrocephala, C. vomitoria, Lucilia, M. stabulans, Sarcophaga, 
H. dentipes, 0. leucostoma and the small Anthomyidae, all of which 
visit in large numbers both excrement and decaying animal matter. 
On the other hand several of the numerically less important species, 
including P. eriophthalma, P. cornicina, M. hortorum, P. lardaria and 
Scatophaga, frequent excrement, but seldom visit animal matter. 
In this country shade seems to be specially repellent to P. groen- 
landica, P. cornicina, M. hortorum and 0. leucostoma, and members of 
some other species belonging to the genera- Calliphora, Lucilia, Muscina, 
Sarcophaga, Hydrotaea and Polietes are seldom found in shady places. 
On the other hand A. radicum and other small Anthomyidae are usually 
abundant in shady places. As very intense heat appears to be harmful 
to flies this statement is possibly incorrect for certain seasons in the 
tropics. 
Sexes of flies caught in traps. 
Reference to Table III will show that of the flies which visited 
these traps only 16,624 (16%) were males, though specimens of this 
sex were often attracted to the neighbourhood of the traps. Males 
were caught relatively more commonly in the open traps. They very 
seldom ventured into the dark receptacles, especially those containing 
animal remains, where the proportion of females was as high as 95 %, 
or, if the males of 0. leucostoma be excluded, 98 %. 
In regard to the important species C. erythrocephala, C. vomitoria 
and Lucilia it may be stated that the males prefer excrement and avoid 
dark and shady places, whereas the females will venture into dark 
receptacles, especially if situated in sunny places, in order to deposit 
their eggs. Certain observations seem to indicate that both sexes of 
these species mainly visit excrement exposed in the open in order to 
feed on it. The excrement from trap I was removed frequently and 
1 Atkinson, E. L. (rv. 1916) found M. domestica, F. canicularis, F. scalaris, G. vomitoria, 
C. erythrocephala, L. caesar, S. carnaria, M. stabulans, and “a stout hairy fly almost 
black in colour” the most prevalent flies in Gallipoli. 
32—2 
