1899] 



CHEESE. 



Cheese and Bacon Fly. Piophila casei, Linn. 



PioPHiLA CASEI. — 1, fly ; 2, pupa ; 3, pupa-case ; 4, maggot, — all magnified, 

 with lines showing natural length ; 5, tail extremity, still more magnified, showing 

 spiracles, tracheae, and caudal tubercles. 



Most of US, especially those who have to do with manufacture of 

 Cheese, are only too well acquainted with the small white " hopper " 

 maggots which put head to tail, and then, letting go suddenly, disperse 

 themselves by "hops" or "skips" in all directions. 



The infestation is prevalent in America as well as Europe, and is 

 perhaps one of our longest definitely known economic insect pests, as 

 the grubs, which "form themselves into an arch and leap in fat 

 Cheese," are recorded as a North European trouble so far back as the 

 year 1555.* 



" Live Cheese," as it is called, is a cause of great loss where the 

 infestation is not looked after in its early stages, though I am assured 

 by various lady dairy superintendents who have been good enough to 

 communicate with me, that by the use of careful preventive measures 

 they suffer little ; and in the course of the following pages I give notes 

 of the treatment regarding which they have been good enough to let 

 me have information. 



But the great injury sometimes caused to Bacon and Ham by the 

 "hopper" maggots of the same kind of ^y (Piophila casei, scientifi- 

 cally) is much less known of, or at least much less acknowledged, and 

 brought forward as a thing to be got rid of. It might probably save a 

 deal of loss if this fact — that is, the similarity of the infestation — was 



* Bee observations on "fat " Cheese, and note, p. 15. 



