DIPTERA. 425 
their development, a number of generations being produced each year. 
The prompt disposal of dung would therefore help greatly in reducing 
the numbers of this pest. 
THE MEAT FLY oR BLow FLY. 
(Calliphora vomitoria Linn. ) 
This fly agrees quite closely with the flesh fly in habits, except that it 
deposits eggs instead of living larve. The eggs, however, hatch very 
quickly after deposition, so the effect is very much the same. Like 
that species it has long been known as a troublesome insect and was 
described by Linneeus. It is a large species and familiar as the large 
blue fly which so noisily frequents the window or seeks entrance to pan- 
tries, cellars, and storerooms where eatables are kept. 
With that species also it is credited with attacking fresh wounds, and 
Packard states that during the war of the rebellion they were griev- 
ously tormenting to our soldiers, laying their eggs in the wounds, 
especially of those left on the field over night. 
On domestic animals where these “fly blows,” as they are commonly 
called, occur, the same treatment suggested for the flesh-fly may be 
practiced. 
BLUE-BOTTLE FLY. 
(Lucilia cesar Linn.) 
In history and habits this species is very similar to the preceding 
species and it is unnecessary to go into detail with regard to it. It is 
one of the first to put in its appearance in spring, having lived through 
winter in some sheltering corner. Its eggs are deposited upon any 
available fleshy matter and the larve mature rapidly. 
Packard, in mentioning its habits, says: 
Dr. Chapman, of Apalachicola, writes to Mr. Sanborn that this fly, attracted by 
the stench of a mass of decaying insects which have perished in the leaf of Sarra- 
cenia, ventures in and deposits its eggs, and the larve devour the festering heap. 
These in turn, on becoming flies, are unable to get out of their prison, perish, and 
are added to the putrefying mass that had nourished them. (Guide, p. 104.) 
THE SCREW-WoRM FLY. 
(Compsomyia macellaria Fab.) 
The screw-worm is unquestionably one of the most important of all 
the insects that affect domestic animals, and while the literature of the 
subject deals largely with its attacks upon man, on account of its very 
general fatality when gaining entrance to the openings of the face, by far 
the greater number of its attacks are upon the lower animals, and it is 
principally in this connection that we purpose to discuss it here, inelud- 
ing such reference to its hominivorous attacks as may furnish aid in 
understanding its mode of work. 
Tren ee 
