72 



Lamson (G. H.). Mercurial Ointment, an effective Control of Hen 

 Lice. — Jl. Econ. Entom., Concord, N.H., x, no. 1, February 1917, 

 pp. 71-74. 



Powders and dust baths as a control for lice on fowls are considered 

 inefEective. Continued applications have failed to control this pest, 

 owing to the fact that the birds shake much of the powder out of their 

 feathers immediately after application, while most powders lose their 

 efficiency long before the next generation of lice is hatched. Mercurial 

 ointment does not act as quickly as some powders, but within a few 

 days the birds treated with it become free from lice and remain so for 

 8 to 16 weeks. Used in full strength, mercurial ointment has been 

 found to cause some burning, but, when diluted with two parts vaseline, 

 the lice are killed and no burning results. Mercurial ointment contains 

 50 per cent, metallic mercury with 50 per cent, petrolatum, and should 

 not be confused with blue ointment, which contains 67 per cent, 

 mercurial ointment and 33 per cent, vaseline. The method of appli- 

 cation is to take an amount about the size of a pea and rub it into the 

 base of the feathers on those parts of the body where the eggs of the 

 lice are laid. Such applications to be effective should be made three 

 times in the year in the northern States and perhaps six times a year 

 in the south. For young chickens a little sweet oil is advised as a 

 practical control measure owing to the tenderness of the skin. 



Richardson (C. H.). The Response of the House-fly to certain Foods 

 and their Fermentation Products. — Jl. Econ. Entom., Concord, N.H., 

 X, no. 1, February 1917, pp. 102-109. 



This paper describes a series of experiments made with the object 

 of obtaining a more intimate knowledge of the attractive constituents 

 of the preferred foods of Musca domestica. Tables are given recording 

 the results of the experiments, which led to the following conclusions : 

 Glucose, fructose, maltose, lactose, starch and dextrin are not very 

 attractive to house-flies. Lactose and dextrin caught the largest 

 number of flies, starch the least. Sucrose was a poor bait, while 

 4 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 ; 4 per cent, ethyl alcohol was better than 10 per 

 cent., and 10 per cent, acetic acid gave better results than 4 per cent. 

 Succinic and lactic acids showed some attractive qualities. 



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

 amylic alcohol, ethyl alcohol and acetic acid were more attractive than 

 the corresponding aqueous solutions. Maltose and dextrin solutions 

 were more effective than lactose or sucrose. The order of response 

 to the alcohols and acetic acid containing carbohydrate was the same 

 as that for the aqueous solutions of these compounds. Crude glutin 

 from wheat flour proved unattractive. The water soluble portion 

 with or without starch in suspension was decidedly attractive. Several 

 experiments with milk indicate that fat-free caseinogen is attractive, 

 while butter-fat is not. Aqueous solutions of wheat flour and molasses 

 to which sodium arsenite and amylic alcohol are added have consider- 

 able value as poison-baits for house-flies. 



In the course of the discussion following this paper, it was stated 

 that pig-blood had proved more attractive than any other substance 

 tried by another investigator. 



