222 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 1(5 
PROGRESS REPORT OF INVESTIGATIONS RELATING TO 
REPELLENTS, ATTRACTANTS AND LARVICIDES FOR THE 
SCREW-WORM AND OTHER FLIES 
By F. C. Bishopp, F. C. Cook, D. C. Parman, and E. W. Laake, United States 
Department oj Agriculture 
Abstract 
Among many tests of baits for use against the screw worm fiy, (Chrysomya macellaria) 
and its relatives dried egg was found to be one of the most satisfactory. Over two 
hundred chemicals were tested as repellents for use on live stock. Some of the most 
promising were furfural, safrol, salicylic aldehyde, several essential oils—namely 
cloves, cassia, citronella, fennel, sassafras and anise—pine tar oils and certain cam¬ 
phor oils. A very effective repellent for practical use is a mixture of one part furfural 
to four parts pine tar oil. As a larvicide for use on wounds benzol is satisfactory. 
The need for a detailed study of the chemotropic responses of various 
species of flies has been pressing for years. The economic importance of 
one phase of the problem, viz., the losses caused by the screw worm and 
other blowflies is world wide. In the southwestern United States they 
cause a loss to the live stock industry estimated at four million dollars 
per year. The losses to the sheep industry of Australia are placed at 
twenty million dollars annually and heavy losses are experienced in 
tropical America, India and Africa. 
The problem of their control has been under investigation by the 
Bureau of Entomology since 1915 when an investigation of the relation of 
flies to the packing houses under government control was undertaken in 
co-operation with the Bureau of Animal Industry. A study of the control 
of the screw worm fly in the Southwest was started the same year. 
During the past two years the Bureau of Chemistry has co-operated in 
the work on these investigations and they have been pushed whenever 
seasonal and other conditions were favorable. 
The field is large, covering the responses of different species of flies 
to various chemicals, etc., both attractants and repellents. While 
considerable progress has been made the problem has many aspects and 
it is planned to continue the co-operative work and to apply the infor¬ 
mation obtained in the present studies to other species of flies. 
The experiments thus far have been divided into three groups (1) 
Seeking chemical groups or combinations that will attract flies of eco¬ 
nomic importance, especially blowflies and house flies, (2) Seeking groups 
or combinations which will repel these flies from decomposing meat or 
similar materials which are particularly attractive to them, (3) Seeking 
ovicides and larvicides suitable for use on infested live stock. 
In the early stages of the work jars containing meat were treated with 
