38 



BULLETIN 1453, U. S. DEPARTMENT OF AGRICULTURE 



for 38 hours, in 95 per cent alcohol for 32 hours, and in xylol for 7 

 hours. Ultraviolet rays (4) completely stopped development, where- 

 as radium emanations merely arrested development in most cases. 



Other trials of a like nature were reported in 1909 by Krausse 

 (Jfi) , who used as a check for comparison specimens of an ant, Messor 

 structor Ltr. His skipper larvae were alive after 90 minutes in 96 

 per cent alcohol, after 301 minutes in spring water, and after 1,030 

 minutes in glycerine, the ants being apparently dead in each liquid 

 after 4 minutes or less. Krausse also found that chloroform caused 

 instant death. 



Sakharov (67) found that infested fish may be freed of the larvae 

 by immersion for from 3 to 5 days in a strong brine solution, and 

 with these results in mind he suggested that the larvae may be 

 successfully removed from cured meats in the same way. He tried 

 several liquids as larvicides and found that larvae remain alive in 

 kerosene for 5 hours and in benzene for 10 minutes. 



Trials by the writer with some common reagents agreed with the 

 results of Alessandrini, Krausse, and Sakharov in that they show the 

 remarkable resistance of the maggots when exposed to conditions 

 ordinarily considered fatal to insects. However, chloroform did not 

 give instant death. None of the materials tried gives promise of 

 being useful for killing larvae in meat. The requirements for this 

 work are that the liquid be inexpensive, that it should quickly kill 

 larvae deep in the meat, and that it should not affect the taste or keep- 

 ing qualities of the meat. Prolonged soaking, as recommended by 

 Sakharov, or more rapid dipping would be the method used in 

 applying a liquid for this purpose. The materials used in the experi- 

 ments recorded in Table 16 are obviously unfitted for either of these 

 purposes but the results are included in this bulletin to emphasize 

 the unique hardihood of the maggots of P. casei. Following immer- 

 sion, the larvae were dried on a blotter and placed in ventilated pill 

 boxes. The results given show that many formed puparia and that 

 some of the pupae had sufficient vigor to become adults. In several 

 of the trials the skipping power of the maggots returned soon after 

 their removal from the liquids. 



Table 16. — Results of immersing migrant 



liquids 



larva? of Piophila casei in various 





Duration 



of 

 immersion 



Total 

 larvae 

 used 



Condition of larvae 24 hours after removal from liquids 

 to pill boxes 



Liquid used 



Dead 

 lar- 

 vae 



Live 

 lar- 

 vae 



Pu- 

 paria 



Remarks 



Gasoline 



Hrs. 



Min. 

 30 



"~30" 



15 



""H 



1 



Vi 



1 



""26" 



5 

 12 

 34 



13 

 14 

 15 

 14 



13 

 11 

 9 







i 



i 

 u 



2 



12 

 8 



10 

 9 



11 

 



4 

 5 



10 

 

 3 

 3 

 1 

 3 



1 

 6 

 4 



5 



1 

 

 

 2 

 

 

 

 6 

 3 

 9 

 10 





Do 



1 

 1 

 2 



3 



24 



2 larvae able to make some progress. 

 6 larvae able to make some progress. 



Do 



Do 



Do. 



1 larva able to skip. 

 3 larvae able to make some progress. 



Do 







Do 





8 

 5 



2 

 





Carbon disulphide... . .. 







Do 





12 

 9 

 14 

 11 

 12 

 15 



2 

 9 

 5 

 5 

 2 

 2 





Do 



24 









Ether: 







Ethyl acetate 







Ammonia (concentrated 

 solution) . 





3 of the larvae skipping. 



