of the biggest we face today. Increasing the 
amount of insecticide would only increase the 
threat of contaminating our food, our environ- 
ment, and ourselves. Clearly, means are 
required to supplant or alleviate the need 
for toxic pest-control chemicals, and new 
approaches to the control of insect pests 
deserve to be investigated fully. 
With this background, it is easy to see why 
the idea of using innocuous odors to control 
insect pests is particularly inviting these 
days. 
Are we grabbing at straws, or does this 
approach really have substance? There is 
already enough well-documented evidence to 
establish the value of attractants in pest 
control, Before venturing off into the misty 
future, allow me to present some of this 
evidence. 
Thus far attractants have proved useful 
for two purposes--detection of infestations 
and direct control. In either case, these tech- 
niques are based on the well-established fact 
that the survival of many insect species is 
fostered by their keen, specialized sense of 
smell, which guides them to food, the op- 
posite sex, or a place to lay eggs (3). Social 
insects even manufacture their own odors, 
which they employ to warn others in the 
colony of impending danger, to recognize 
intruders, to gather food, or to enlist the aid 
of other colony members (4). The action 
of some of these odors is powerful enough 
in terms of the infinitesimal quantities needed 
and intensity of response to make them 
potentially valuable for combating economi- 
cally important species. We would like to 
employ this important insect survival mechan- 
ism to control and even to eradicate harmful 
insects, 
The powerful attractants found thus far 
are highly specific, that is, they will attract 
one or a few closely related species and then 
only the males, 
For detection purposes, traps are baited 
with a specific lure; wherever insects are 
caught and as long as they are caught, control 
measures may be applied. This makes for a 
most efficient operation. Insecticides are not 
spread needlessly. Money is saved because 
insecticides are not wasted. Residues are 
held to a minimum. 
35 
The further spread of the gypsy moth 
[Porthetria dispar (L.)] from the Northeastern 
United States has been prevented for at least 
20 years now through the use of traps baited 
with a stabilized sex attractant for the 
moth (5). Soon after the female gypsy moth 
emerges from pupation it emits an odor, i.e., 
a sex attractant, which lures the male to it 
for mating. The attractive odor ceases after 
mating. At first, traps were baited with a 
stabilized extract laboriously obtained at great 
expense from hundreds of thousands of virgin 
female moths. In 1960, the sex attractant was 
identified and synthesized (6), and subsequently 
a closely related attractant called gyplure 
was synthesized from the commercially 
available ricinoleyl alcohol (7). The com- 
paratively inexpensive gyplure is now used to 
bait the 50,000 traps set out in the New 
England area every year to map the where- 
abouts of the moth. 
When the highly destructive Mediterranean 
fruit fly [Ceratitis capitata (Weidemann)], 
or medfly, turned up in Florida in 1956, 
specific powerful attractants (8) in traps 
pinpointed the pockets of infestation and 
guided the application of control measures, 
which were mainly the application of malathion 
in a protein hydrolyzate bait (9). Even though 
the insect was found on a million acres, 
well scattered over much of Florida, the 
medfly was eradicated the following year. 
The eradication campaign cost almost $11 
million. 
Surveillance with the attractant-baitedtraps 
was continued. Reinfestations occurring in 
1962 and 1963 were picked up by a powerful 
new synthetic called trimedlure (10). The 
incipient infestations were wiped out within 
a month or so at relatively small cost to 
the Government, U.S. Department of Agri- 
culture officials estimate that the early de- 
tections saved the Government $9 million in 
potential eradication costs. 
When an attractant is used for direct con- 
trol, it is combined with a toxicant; the 
supreme advantage of this approach is that 
the toxicant hits the target organism. About 
a year ago, through the use of a _ specific 
attractant, Department entomologists eradi- 
cated the oriental fruit fly (Dacus dorsalis 
Hendel) from the 33-square-mile isolated 

