(4) Finally, they are there, waiting to be 
manipulated and used; they do not have to be 
invented, developed, or manufactured, 
As parasites and predators have all these 
advantages over chemical pesticides, you may 
wonder why their demonstrated potential is, 
as I have shown, by no means adequately 
exploited. 
One of the most important reasons for this 
arises from a disadvantage of parasites and 
predators as compared with chemical pesti- 
cides: they are usually relatively slow in 
producing their effects. It may take weeks, 
months, or years for them to get pest popu- 
lations under control. Growers prefer some- 
thing that produces immediate and visible 
results, as do chemical pesticides, even if 
those results are only temporary. 
A supplementary disadvantage arises from 
the fact that parasites and predators are 
alive, and thus to some degree inherently 
variable in their characteristics and un- 
predictable in their behavior: a living orga- 
nism does not always do exactly what another 
living organism--in this case, man--wants it 
to do. 
The other important reason why parasites 
and predators are inadequately used in pest 
control is inadequate information. The grower 
does not know enough about how they might 
be used to his advantage because the people 
who advise him do not know enough about 
this. They do not know enough because enough 
is not known. Enough is not known because 
not enough research is being done. There is 
not enough research because there are not 
enough suitably trained people to do it. There 
are not enough suitably trained people because 
enough highly trained specialists are not 
being trained by the universities, and they do 
not train them because they lack the special- 
ists to do so, and because students tend to 
gravitate to subjects that receive publicity 
because they have the money to publicize. 
There are, for example, only two univer- 
sities in the United States, and none in Canada, 
that have adequately sized departments of 
biological control. A result is that the demand 
for specialists far exceeds the supply, and 
every biological control research center has 
a problem of staff shortage, which has arisen 
from the fact that the need for research in 
the subject has increased faster than an in- 
68 
crease in the number of specialists available 
to do that research. 
I have surveyed briefly the present role of 
parasites and predators on insect control. 
The other aspect is their future role. The 
first question that arises is, will parasites 
and predators be used increasingly? The 
answer is yes. As I have just indicated, there 
is already a marked trend in this direction. 
Evidence of this is that the various existing 
national and international biological control 
research agencies have expanded in recent 
years or are in the process of doing so, 
and new ones are being established or are 
planned; and the amount of research, as indi- 
cated by the number of research papers 
published annually, has more than doubled in 
less than 10 years. 
Incidentally I should perhaps mention here 
that Canada recognized early the importance 
and potential value of parasites, predators, 
and other biological controls and developed 
and supported study of them. As a result, we 
now give, through the Federal Departments 
of Agriculture and Forestry, relatively much 
more attention to research in this subject, 
and have done so longer than most other 
countries. 
The second question is, will the amount of 
research increase sufficiently rapidly to meet 
the needs? There are two main needs. The 
first is to find effective alternatives to the 
excessive use of chemical pesticides, because 
of their toxic and other harmful effects. The 
second is to develop the optimum control 
program for each pest situation. As I indi- 
cated earlier, most optimum control programs 
are likely to be integrated controls, in which 
parasites, predators, and related natural con- 
trols are manipulated to make them operate 
as efficiently as possible and chemical pesti- 
cides are applied to supplement these effects 
without harming them, 
Optimum control programs are of course 
highly desirable at present. A time will come 
when they will be essential rather than de- 
sirable. They will become essential when the 
increasing world population makes pest control 
essential: when we will be unable to continue 
to afford to feed both pests and people. Then 
it will be essential both to apply control 
measures and to apply the best ones. A 
situation may develop where the prevention 

