224 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 16 
etc. Gut slime, the mucous lining of hog and cattle intestines removed 
during their preparation for sausage casings, is very attractive to these 
flies. As fresh slime can not be shipped the drying of the material was 
tried. The dried product however, proved less attractive to the blow¬ 
flies than the fresh slime probably due to the volatilization of amines 
and ammonia and certain acids during the drying process. The bacterial 
flora was also reduced by the drying. 
Experiments conducted recently have shown that dried whole egg or 
dried egg yolk when moistened and kept alkaline makes a very attractive 
bait for flies. The dried egg material which is available commercially 
and that which may be made from eggs not suitable for food has given 
excellent results around packing houses and on the cattle ranges. Dried 
egg material made from off grade eggs must be clearly labeled to show 
that it is unfit for food purposes. A reduction in the number of screw 
worm cases among cattle has been noted on ranches where this bait has 
been properly used with traps. 
A mixture of dried egg, water and sodium carbonate in the following 
proportions is recommended: 170 grams (6 ozs.) dried egg, 2 quarts of 
water, and 5 grams (1 /5oz.) sodium carbonate. The mixture should be 
placed in clean bait pans under suitable traps. It is important to keep 
the bait moist, and to add sodium carbonate occasionally to keep the 
mixture alkaline. 
Other protein material such as rabbit carcasses may be used in traps, 
the essential point being the development of protein decomposition 
products and their expulsion by alkaline conditions. The objection to 
the development of fly larvae in baits composed of meat products has 
been met by the use of a larvicide surrounding such baits in the pans. 
Solutions made by mixing 10 cc. (Y oz.) of 40% nicotine sulphate 
solution or by dissolving 15 grams (}4 oz.) of borax in 2 quarts of water 
proved satisfactory. 
The species of flies studied principally in the tests of attractants and 
repellents were (arranged approximately according to abundance) 
Musca domestica L., the screw-worm fly ( Chrysomya macellaria Fab.), 
black blowfly ( Phormia regina L.), greenbottle fly ( Lucilia sericata 
Meig.), PiopJnla casei L., Sacrophaga spp., and Ophyra leucostoma 
Weid. 
