10 CHEESE. [1899 



are given further on ; but it is plain that salt cannot be utilized as a 

 remedial agent, both from our constant broadscale experiences, and 

 also as it was found by Germar that the maggots would live in 

 common salt alone. 



It will be observed in the details of life-history following, that it is 

 such a marked and recognised habit of the flies to come in from out of 

 doors through open doors or windows, that one of the regular preventive 

 measures in the United States is to exclude them by fixing up screens 

 of wire-work of a mesh sufficiently small to keep them out. In a case 

 reported to me it was said, " We closed out and indoors with open 

 canvas." But we have no observations (so far as I can see) whence 

 these invading quantities of flies come. 



In the following notes with which I have been favoured, I give them 

 as received, as it would have taken from the value of the information 

 to separate the observations of preventive treatment from those of 

 condition of material accompanying ; and as attack to Bacon and 

 Ham has been least entered on in this country, I give the notes on 

 this subject first. 



Attack of ^^ hopper" maggot to Ham and Bacon. — The following com- 

 munication was sent me by the secretary of one of our Ham and Bacon 

 Curing companies, which I am allowed to give, as well as some further 

 observations on the attack and preventive measures, under promise of 

 withholding name and locality of inquirers : — 



" We are troubled with fly in our Hams under the following cir- 

 cumstances, and we are now venturing to communicate with you, 

 believing you may suggest a remedy for the evil, which is a serious 

 one to us. We find a small long pinky ego deposited in the Ham, 

 sometimes in its early days of cure, say two to three weeks old, but more 

 frequently when twenty- six to twenty- eight weeks old. The eggs burst 

 and become a nest of white hoppers similar to those found in Cheese. 

 . . . The Hams are sweet-cured, and we hang them separately to 

 mature, but notice in the store-room several small flies ; . . . and we 

 think the later trouble results from these. It is puzzling, however, 

 how the fly or hopper gets in when the Ham is only two or three weeks 

 old. Could you suggest any solution or otherwise that would prevent 

 these flies working, or hoppers forming?" 



On July 10th, the Secretary of the Company above mentioned 

 further communicated to me, enclosing a small piece of the infested 

 meat, and also a little bottle containing some of the flies, which, he 

 remarked, "you will see are as you describe— small, black, and two- 

 winged." 



The flies sent were about fifty in number, and corresponded with 

 descriptions of the Fiophila casei, popularly the Cheese and Bacon Fly. 

 They were about one-fifth of an inch in length, black and shiny, two- 



