G 



Fig. G. — A stublo fly (Cyrtoneara utabitlans): a, egg: b, 



writer's experience with the use of air-shiked lime on cow manure to 

 prevent the l)reeding' of the horn fly sugo-ested experimentation with 

 different lime compounds. It vcas found to be perfectly impr.:cticable 

 to use air-slaked lime, land j^laster, or gas lime with good results. 

 Few or no larviv were killed by a thorough mixture of the manure 

 Avith any of these three substances. Chlorid of lime, however, was 

 found to be an excellent maggot killer. AAliere one pound of chlorid 

 of lime was mixed Avith eight quarts of horse manure, 90 per cent of 

 the maggots Avere killed in less than twenty-four hours. At the rate 

 of a quarter of v. \}Qi\nd of chlorid of. lime to eight quarts of manure, 

 hoAvcA^er, the substance Avas found not to be sufliciei,itly strong. 

 Chlorid of lime, though cheap in Europe, costs at the least ?)i cents a 



jxjund in large quantities in 

 this country; sotliatthe fre- 

 (luent treatment of a large 

 manure pile Avith this sub- 

 -^tance Avould be out of the 

 question as a practical meas- 

 ure. 



Experiments Avere, there- 

 fore, carried on Avith kero- 

 sene. It was found that 



same enlarged; c, larva; c/, head of same magnified; e, pio-1if nn-ii-fc r>-f -fvp^li Imv^o 

 puparium; /, adult-all enlarged except a (after Com- "'^^^^^ qiuii Lb Oi iiLbU JKUSi 



^^°^^)- manure sprayed Avith one 



pint of kerosene, Avhich Avas afterv\ards Avashed clown Avith one quart 

 of water, Avas thoroughly rid of living maggots. EA^ery indiAndual 

 was killed by the treatment. This experiment and others of a similar 

 nature on a small scale Avere so satisfactory that it Avas considered at 

 the close of the season that a practical conclusion had been reached 

 and that it Avas perfectly possible to treat any manure pile econom- 

 icall}^ and in such a Avay as to prevent the breeding of flies. 



Practical Avork in the summer of 1898, hoAvcA^er, demonstrated that 

 this Avas simply another case where an experiment on a small scale has 

 failed to dcA'elop points Avhich in practical Avork Avould A'itiate the 

 results. 



The stable of the U. S. Department of AgTiculture, in Avhich al)out 

 tAveh'e horses are kept, is situated about 100 yards behind tlie main 

 building of the Department and about 90 yards from the l)uilding 

 in Avhicli the Di\dsion of Entomology is situated. The stable has 

 alAvays been A^ery carefully kept. The manure has been thoroughly 

 SAvept up cA-ery morning, carried outside of the stal)le and deposited 

 ill a pile behind the building. This pile, after accumulating for a 

 Aveek or ten days, or sometimes two Aveeks, is carried off by the gar- 

 deners and spread upon distant portions of the grounds. At all 

 times in tlie summer this manure pile has been sAvarming Avith the 



[Cir. .•!.-.] 



