HOUSE FLIES. 3 
It is not so active as the house fly and, particularly in the fall, is very 
sluggish. At such times it may be picked up readily, and is very 
subject to the attacks of a fungous disease which causes it to die upon 
the window panes, surrounded by 
a whitish efflorescence. Occasion- 
ally this fly occurs in houses in such 
numbers as to cause great annoy- 
ance, but such occurrences are com- 
paratively rare. It is said in its 
earlier stages to be parasitic on cer- 
tain angleworms. 
A fourth species is another stable 
fly, known as Muscina stabulans 
Fall. (fig. 3), a form which almost 
exactly resembles the house fly in 
general appearance, and which does 
not bite, as does the biting stable fly. pyc, 4.—one of the pblue-bottle flies 
It breeds in decaying vegetable mat- NOS LO NONE EAE oii eS 
An larged. (Author’s illustration.) 
ter and in excrement. 
Several species of metallic greenish or bluish flies are also occa- 
sionally found in houses, the most abundant of which is the so-called 
bluebottle fly (Calliphora erythrocephala Meig.). 'This insect is also 
called the blow fly, or meat fly, and breeds in decaying animal mate- 
rial. A smaller species, which may 
be called the small bluebottle fly, is 
Phormia terraenovae Desv. (fig. 4), 
and a third, which is green or blue 
in color and a trifle smaller than 
the large bluebottle fly, is Lucilia 
caesar Li. (fig. 5). 
There is still another species, 
smaller than any of those so far 
mentioned, which is known to ento- 
mologists as (Homalomyia) Fannia 
canicularis 1i., sometimes called the 
: small house fly. A related species, 
Fic, 5.—The green-bottle fly (Lucitta FF. brevis Rond., is shown in figure 
aeuaaey enlarged. (Author's 6. F. canicularis is distinguished 
from the ordinary house fly by its 
paler and more pointed body and conical shape. The male, which is 
much commoner than the female, has large pale patches at the base 
of the abdomen, which are translucent when the fly is seen on the 
window pane. It is this species that is largely responsible for the 
prevalent idea that flies grow after gaining wings. Most people 
think that these little fannias are the young of the larger flies, which, 
