18 CHEESE. [1899 



get iu at the edges.* The brown fly-paper used by laying in water is 

 serviceable in broadscale treatment, and any other fly-papers or fly- 

 killers ivhich answer these purposes are trustworthily recommended. I 

 do not find that fumigation is much used with us, but in U.S.A. 

 practice it is noted that the flies speedily succumb to the fumes of 

 burning sulphur or pyrethrum powder, and the latter, if dusted upon 

 the flies, stupefies them.f The Bacon Company whose notes I give at 

 pp. 12, 13, preceding found a fly powder of great use. 



The flies are not active at night, and to make the Cheese-rooms as 

 dark as possible is one method with us of lessening attack ; but the 

 success of this would probably depend on the extent of the darkening, 

 for if this is only partial the fly can still work. 



Remedial and preventive measures to destroy infestation in maggot or 

 other stage in stores or Cheese-rooms, — Thorough fumigation early in the 

 spring, and also thorough whitewashing, using an addition of carbolic 

 acid, " thus eflectually sealing up or killing all hibernating individuals 

 that might be lurking in these places" (M. E. M.).| Every crack 

 should be carefully looked to which may be serving for a sheltering 

 place from which the pest might wake up in fly, or develop out of 

 chrysalis state, with the first warm weather. 



Shelves should be kept carefully cleaned ; floor and benches also 

 thoroughly scrubbed, and {wherever it can be used) kerosene emulsion, 

 or its British counterpart (soft-soap wash with a little parafiin or other 

 mineral oil stirred into it), should be liberally scrubbed in. Careful 

 attention to such measures as the above should be kept up during the 

 whole of the season whilst the fly is active. As the maggot by no 

 means certainly turns to chrysalis state in its feeding ground — indeed, 

 in some cases certainly it seeks a drier locality — it is necessary to take 

 such measures as may destroy such as are scattered, or sheltered near 

 the food. 



Where the stores can be emptied, and steam-power is present, it 



* Note. — Wliere do these Jlies come from? It is plain from treatment to exclude 

 them being a regular part of preventive treatment, that this entrance from outside 

 is a part of the well-established life-history, and if we knew where they came from 

 it might help us much. Do they propagate more than has been traced out at pre- 

 sent in decaying filth ? Taschenberg, in his Piophila casei, ' Praktische Insekten- 

 kunde,' pt. iv. pp. 141, 142, mentions that they were found by Germar to breed in 

 human excrementitious matter when half decayed. 



t Pyrethrum powder is procurable in this country under the name of Persian 

 powder, and if fresh acts trustworthily ; but probably it is well to see whether after 

 a time the flies would revive, and if so to sweep them up and destroy them. The 

 only objection mentioned to the use of the sulphur is that it was found to give 

 a streaked look to the wash used by the firm (U.S.A.), who especially reported 

 on it. 



I It should be borne in mind that crannies in roofs and ceilings may shelter 

 the tlies as effectually as those in walls or floors. 



