THE CHEESE SKIPPER. AS A PEST IN" CURED MEATS 37 



ing the surface of cured meats, but its use in meat products subject 

 to the Federal meat inspection law is prohibited except in the case of 

 shipments destined for certain foreign countries. 



One of the preventive measures employed by commercial firms 

 is rapid handling of the product; that is, meats are smoked near 

 the retail markets and as far as possible are distributed to the re- 

 tail trade promptly after the smoking is completed. 



It is probable that a screened closet or cage carefully made with 

 30-mesh wire cloth would prove adequate and satisfactory for use on 

 farms and in retail stores where cured meat is stored for several 

 weeks or months. Such an inclosure would represent an initial ex- 

 pense only, and on farms would give protection without the necessity 

 of wrapping and dipping meat. Screened closets in retail stores 

 observed by the writer have been ineffective because the wire cloth 

 used in their construction was too coarse. 



But both where meats are screened and where they are wrapped the 

 efficiency of the methods depends upon their application to hams, 

 shoulders, and bacon which are not infested. Inspection of suspected 

 pieces of meat can not give the assurance that they are free from eggs 

 or larvae of P. casei because the former are small and hidden in crevices 

 by the female fly and the latter burrow so deeply that it is necessary to 

 cut a ham in half before their favorite feeding spots can be examined. 



Curing and smoking meats on farms during cool weather when the 

 adult flies are not active is a good way to make certain that meats 

 will not be infested before they are protected by wrappings or screens. 



It has been recommended that smoked meats be wrapped and buried 

 in a grain bin (55) or in sawdust or bran (1). 



KILLING P. CASEI IN INFESTED MEAT 



In the control of P. casei it would be desirable to be able to kill 

 all insects and eggs in infested meat so that it can be definitely known, 

 before shipping, wrapping, or screening suspected stocks, that they 

 are free from infestation. This is difficult, because of the deep-seated 

 nature of the infestations, the remarkable resistance of the larvae, and 

 the necessity for avoiding undesirable changes in the meat treated. 



Swammerdam (73, p. 65) appreciated the vitality of the maggots, 

 which when put in rain water lived for six or seven days. Curtis 

 (17) decided that fumigation with sulphur was "a very doubtful 

 remedy," and Murtfeldt (58, p. 175) found that this treatment im- 

 paired the appearance of sacked hams coated with yellow wash. 

 Smith (70, p. 368) asserted that fumigation with tobacco or pyre- 

 thrum did not kill the maggots, although the adults succumbed. Grin- 

 nan (29) removed skippers from infested meat by sunning it, a process 

 which, he maintained, brings the maggots to the surface and kills them. 



TREATMENT OF LARVAE WITH CHEMICALS AND WITH RAYS OF SHORT WAVE LENGTH 



Extensive experiments with about 70 reagents as skipper larvicides 

 have been made by Alessandrini (4). Chloroform he found to be 

 instantly fatal, and death was speedily caused by immersion for one 

 minute in carbon disulphide. He suggested the possibility of eradi- 

 cating the pest in cheese factories by the fumes of chloroform, diluted 

 with water for the sake of economy. In his experiments larvse 

 survived in spring water for 280 hours (nearly 12 days) ; in paraffin 



