DESTRUCTION OF FLY LARViE IN HORSE MANURE. 19 



two experiments and are therefore to be regarded as only tentative. 

 However, the results of the cage experiments are in general agreement 

 with the findings as given in the diagram. 



It will be noted that the highest larvicidal effect was obtained with 

 borax, using 1 pound to 8 bushels. The least expensive treatment 

 was that with 0.62 pound of borax, although the larvicidal action was 

 only 90 per cent. The next cheapest was hellebore, which costs 5h 

 cents for one-half pound of the powdered roots, and the average of 

 12 experiments showed a larvicidal action of 95.5 per cent. The 

 hellebore treatment at the foregoing rate costs more than that with 

 0.62 of a pound of borax but shows a greater efficiency. 



In comparing the cost we have assumed that borax can be obtained 

 at 5 to 6 cents per pound in 100-pound lots and that hellebore can be 

 purchased at 11 cents per pound in like amounts. The price of both 

 is subject to considerable variation. The results in general indicate 

 that the larvicidal action varies with the amounts used, except in the 

 case of nitrobenzene, where the value seems to depend on the pro- 

 portions of nitrobenzene and soap in the emulsion. 



It will be noted that pyridine and aniline, when used in amounts 

 sufficient to kill a high percentage of the larvae, are quite expensive, 

 and for this reason their use can not be considered practical. 



APPLICATION OF HELLEBORE TO MANURE. 



Powdered hellebore should be mixed with water at the rate of 

 one-half pound to 10 gallons and the soJution thoroughly stirred 

 and allowed to stand for several hours in a barrel or other container. 

 In order to obtain the most satisfactory results, the manure should 

 be sprinkled with the foregoing solution immediately on removal 

 from the barn. The sprinkling may be done with a watering can or 

 similar device, using 10 gallons to 8 bushels of manure, taking care 

 that all of the hellebore comes in contact with the manure and paying 

 particular attention to the outer edges of the pile. In estimating the 

 amount of solution to be employed it may be assumed that 2 bushels 

 of manure per horse is the daily output of the stable. This is a liberal 

 estimate, and in many stables the daily output is much less. 



EFFECT OF HELLEBORE ON PLANTS AND CHICKENS. 



During November, 1914, a series of tests was started at both 

 Baton Rouge and New Orleans, La., to determine whether hellebore, 

 when applied in considerable amounts, exerts injurious effects on 

 plant growth. The plants grown included cabbage, lettuce, oats, 

 turnips, radishes, potatoes, wheat, and mustard, half of each plat 

 being fertilized with hellebore-treated manure, and the other half 

 receiving untreated manure. At the present time no injurious 



