108 journal of economic entomology [vol. 10 



Practical Application 



While it was not possible to subject any of the materials used in 

 this investigation to rigorous field tests, a few experiments indicated 

 that the water soluble part of wheat flour, technical amylic alcohol, and 

 molasses solution containing amylic alcohol have considerable value as 

 fly baits. The aqueous wheat flour solution was made up with 1 gram 

 of sodium arsenite and 4 cc. of amylic alcohol to each 100 cc, the mo- 

 lasses was diluted with water 1 to 2 or 1 to 3 and the same amounts 

 of sodium arsenite and amylic alcohol were added. The materials 

 were exposed in shallow dishes. Many flies were poisoned, but without 

 control over the breeding places it was impossible to effect a permanent 

 reduction in their number. It should be added that amylic alcohol has 

 certain drawbacks. It evaporates rather quickly and is only slightly 

 soluble in water rendering an even mixture difficult. 



Conclusions 



The following conclusions are drawn from these experiments: 



(1) Glucose, fructose, maltose, lactose, sucrose, starch and dextrin 

 were not very attractive to house-flies. Lactose and dextrin caught 

 the largest number of flies, starch the least. Sucrose was consistently 

 a poor bait. 



(2) Four per cent amylic alcohol gave better results than ethyl 

 alcohol, or acetic acid in 4 or 10 per cent concentrations and better 

 than 10 per cent amylic alcohol. Four per cent ethyl alcohol was 

 better than 10 per cent, 10 per cent acetic acid gave better results 

 than 4 per cent. Succinic and lactic acids showed some attractive 

 qualities in two experiments. 



(3) Maltose, lactose, sucrose and dextrin in 4 per cent solutions of 

 amylic alcohol, ethyl alcohol and acetic acid were more frequently 

 visited by house-flies than the corresponding aqueous solutions. Mal- 

 tose and dextrin solutions were more effective than lactose or sucrose. 

 The order of response to the alcohols and acetic acid containing carbo- 

 hydrate was the same as that for the aqueous solutions of these com- 

 pounds. 



(4) Crude gluten from wheat flour was not attractive. The water 

 soluble portion with or without starch in suspension was decidedly 

 attractive. 



(5) Several experiments with milk indicate that fat-free caseinogen 

 is attractive while butter fat is not. 



(6) Experiments indicate that aqueous solutions of wheat flour and 

 molasses to which sodium arsenite and amylic alcohol are added have 

 considerable value as poisoned baits for house-flies. 



