6 Insect Life : Its Why and Wherefore 
very severe tax on the mathematician to 
work out the number of house flies which 
one single female may be responsible for. 
The Enemies of the Fly. — These are 
fairly numerous and very diverse. Certain 
species of birds are extremely fond of 
this fly. There are also several forms of 
parasites which attack it. A small reddish 
mite frequently covers its body and in the 
end causes its death. The common house 
centipede destroys considerable numbers, 
as well as some species of beetles, which 
prey upon it. The vegetable world also 
supplies a most effective enemy in the shape 
of a fungus disease known as “ Empusa 
Muscse,” which carries off large numbers of 
house flies, especially towards the end of 
the summer, when they are constantly 
to be seen distended, and unable to move, 
as the internal growth gradually expands, 
the spores being observable around their 
victim. 
Spreading Diseases. — That the house 
fly carries germs of disease can never for 
a moment be disputed. Typhoid may be 
spread by them as well as a large number 
of intestinal germ diseases, such as asiatic 
