94 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 17 
there was a reduction in the attractiveness of the bait when the poisons 
were added in small amounts. Further experiments are needed to 
determine the most desirable and practical stomach poisons, the mini¬ 
mum dosage of each and the influence the stomach poisons may have on 
bait containing alcohols or yeast organisms. 
In the course of the investigation a number of other products named 
in the list were tried. Each was given several trials. Of these agents 
amyl acetate, acetone, acetic acid and milk (wet powdered milk and 
sour whole or skim milk) proved to be fairly attractive in some in¬ 
stances while in other trials they attracted few if any more flies than the 
checks. 
Summary 
To the author the most interesting result in this study was the positive 
chemotropic response of the adults of Hylemyia antiqua Meig., and 
Hylemyia cilicrura Rond., to the odors coming from several alcohols, 
particularly allyl alcohol, iso propyl alcohol, ethyl alcohol and butylic 
alcohol and odors from fermentation by yeasts when mixed with sweet 
substances such as honey, molasses, brown sugar, corn syrup etc. 
Baits containing alcohols remained attractive for a short period (24 
to 48 hours) only while the baits containing yeasts remained attractive 
for 14 to 21 days or longer provided they did not become too dry. 
Sodium arsenite in small quantities did not influence the attractivenes 
of the baits containing the several attractive alcohols but it did in¬ 
fluence the attractiveness of baits containing yeasts, particularly baits 
made from dry yeast. It seems probable that a small amount of sodium 
arsenite may not influence the attractiveness of baits made with wet 
yeasts and this amount may prove to be of sufficient strength to kill the 
flies. 
Acknowledgments. The author is indebted to Dr. T. J. Headlee 
for the opportunity of carrying on this investigation. He also wishes 
to thank Dr. J. M. Aldrich of Washington, D. C., and Dr. H. C. Huckett, 
of Riverhead, N. Y., for help in identifying the species of flies caught in 
the traps. 
President A. G. Ruggles: We will now listen to a paper by Hugh 
Glasgow. 
