THE CHEESE SKIPPER AS A PEST IX CURED MEATS 



47 



Table 19. — Results of exposure of migrant larrw of Piophila easel to larva and 

 adults of Xecrobia rufipes 



Number 



of P. casei 



larvae 



exposed 



Number 

 of N. rufi- 

 pes used 



Stage of N. rufipes used 



Predacity 

 record 

 after 24 

 hours 



20 



4 

 2 

 4 

 2 

 3 

 3 

 2 

 4 

 2 

 4 



{ . 1 



{ I 

 { 'I 





Per cent 

 



20 



do 







20 



.do 







20 



. ..do. 



40 



20 





55 



20 



.do- 



70 



20 



Adults- 



45 



20 



do 



85 



20 



do : 



50 



20 



do 



75 





Adults - - 



\ 60 



20 



Full-grown larvae... . . . . . ... 





Adults ..... ... ... 



| 100 



20 



Full-grown larvae .. . .. ... . _ . _. 





Adults 



} 90 



20 









Adults of Necrobia ruficollis Fab., sometimes found in material 

 infested with P. casei, are also actively predatory upon these mag- 

 gots. Pedieuloides ventricosus Newp., a widespread predacious mite, 

 rarely kills the larva? and flies. 



SMOKEHOUSE CONDITIONS 



A variety of types of smokehouses are in use, ranging from cham- 

 bers the size of a barrel, through the usual wooden or masonry farm 

 smokehouse, to the improved apparatus used by the larger packers 

 (#, pp. 98-102). Some of the improvements in the last class include 

 automatic temperature control, auxiliary heat supply from steam 

 pipes, and gas fuel for burning the smoking sawdust. Some smoke 

 chambers are arranged for continuous operation, the meat being 

 carried up and down during the smoking on a chain conveyor and 

 removed while hot to the hanging room as soon as sufficiently 

 smoked. 



The duration of smoking varies from a minimum of about 24 hours 

 for sweet-pickle hams prepared for a market which desires meat 

 with a high water content, to light, intermittent smoking for five 

 or six weeks as in the preparation of Smithfield hams. The best 

 smoking temperature is about 120° F., but as a usual thing there is 

 considerable variation from an even, optimum heat. 



The time during which cured meats remain in the smokehouse 

 may be divided for purposes of discussion into two parts. The first 

 period, in which the danger of infestation is comparatively small, 

 begins when the meat, wet from soaking and washing following cure, 

 is hung in the smokehouse to dry, and ends when the heat of the fire 

 drops for the last time below 100° F. The second period, during 

 which, in warm weather, infestation is certain in localities where 

 skippers are found, begins when the first period ends and lasts until 

 the meat is removed from the smokehouse. 



After having been washed and hung in the smokehouse, meats 

 need to dry about three hours before the fire is lighted. In view of 

 the fact that dry-salt pork (unsmoked) is sometimes infested, it is 



