76 
Psyche 
[June-September 
we may not understand exactly how a particular measure takes its 
effect. In recent years, developments in practical insect control have 
come thick and fast, particularly in the field of pesticides. The de- 
velopment since World War II of chlorinated hydrocarbons, carba- 
mate and organic phosphate insecticides, distributed by mass aerial 
spray techniques, has revolutionized control work and has raised insec- 
ticide production and aerial application to the status of big businesses. 
But, promising as it seemed in the immediate postwar years, simple 
mass aerial broadcasting of toxic materials has not always led to efficient 
control of the target pest. Furthermore, the extensive application of 
this relatively unselective technique inevitably caused damage to in- 
cidental targets — plants and animals or property valued by humans 
— and there even arose a threat to human health itself. 9 * 20 As such 
damage and threat of damage became more obvious, protest against 
mass air-spraying increased in volume, and naturally the demand 
grew for research into alternative means of control. 
It is my intention now to attempt to illuminate the current status 
and outlook of insect control methods in the United States by out- 
lining four case histories of large-scale insect control programs. It 
is difficult to say how representative these case histories may be, 
considering the very diverse nature of insects and the damage each 
kind does. All four of the, programs are large and expensive ones as 
such operations go, all have been considered to be eradication programs 
at one time or another, and all have been guided or conducted by 
agencies of the United States Department of Agriculture (hereinafter 
referred to as USDA). 
Since these great programs affect or involve many people and many 
diverse vested interests, they are all to some extent controversial. 
Because controversy about them involves many contradictory findings 
and interpretations, it is often difficult to gain a true and unbiased 
conception of what is going on in a given instance. For this reason, 
I have tried to draw my information from as large and varied a group 
of sources as I could find (see Acknowledgements and References 
Cited) . Let us now see if a resume of four programs — Gypsy Moth, 
Fire Ant, Mediterranean Fruit Fly and Screwworm — will help us 
to appreciate the problems of mass insect control. 
THE GYPSY MOTH 
Introduction 
The Gypsy Moth, Porthetria dispar (formerly hymantria dispar ), 
is a variable insect, a native of Eurasia, where it ranges from Portugal 
and North Africa to Japan. The insect was imported to the Boston 
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