12 THE AUD UB’ O Neve eee 
able to all but the few species. The apple orchards mentioned above have 
fewer kinds of pests now than before, but about as much damage as ever is 
done by the many individuals—and it is more expensive than ever to keep 
the damage at a constant level. 
In the tropical rain forest, where there are myriad species and few in- 
dividuals of each, outbreaks of any one species do not occur. Stability in the 
rain forest comes from its diversity. With all ecological niches continually filled, 
there is little chance for invasion. Predators have plenty of alternate foods, 
and so they do not starve when one food becomes scarce. Each species has a 
number of predators and parasites to help keep its number in check, and 
also has some opportunity to protect itself so that it is not wiped out and can 
reproduce. Very different from the rain forest is the arctic tundra which, be- 
cause of unfavorable conditions, is a simple biotic community, with compara- 
tively few varieties, each of which has many individuals. As a result, the 
tundra is unstable as a community. There are great fluctuations of prey and 
predator numbers. Consider the lemmings! 
DESTRUCTION OF NATURAL BALANCES 
These facts of nature show that the more complex a biotic community 
is, the more stable it is and the less subject to outbreaks of pests. Dr. Robert 
L. Rudd, University of California at Davis, states: “If at any point the num- 
bers of a single species are caused to change, the intimacy of the internal 
relations within a _ biotic community ensures that other members will 
change.’’(8) People who favor continued use of toxic, persistent chemicals are 
clearly on the wrong track, Dr. Cole believes, because they eliminate the 
diversity in an area, making it unstable and more given to outbreaks of pests. 
To solve the problem, the pest controllers propose routine treatment of seeds, 
the use of residual and systemic insecticides, and regular spraying whether 
or not there is a pest. 
The monoculture of modern agriculture, with acre upon acre of the 
same crop, and with hedgerows and roadside brush largely eliminated, further 
simplifies the ecosystem. A biotic community resembling the tundra, with a 
sharp reduction in kinds of species and many more individuals of each species, 
is created. The simplification increases both crop yields and pests: “The reali- 
zation that effective ecological management may result in adequate crop 
yields and lowered pest densities is relatively recent and not widely accepted,” 
asserts Dr. Rudd. (8) If people involved in pest control could realize the ad- 
vantages of biological management, probably their resistance to it would 
disappear. In addition to better pest control, other values would be served. 
Present chemical measures, states Dr. Rudd, are often a mixture of need, 
expediency, unbalanced perspective and superficial appraisal. (8) 
Dr. Cole points to another problem, the possible effect of pesticides on 
soil organisms. ‘“‘At least half a dozen types or organisms are essential for 
maintaining the integrity of the nitrogen cycle alone, and the same must be 
true for other essential chemical nutrients. It is really frightening to realize 
that ever-increasing areas are being treated with new chemicals by persons 
who do not give a thought for the welfare of—and who are probably un- 
aware of—the soil organisms on which the very continuation of life de- 
pends.’’ (3) 
What to do? Patently, there must be a new perspective in the overall 
pest control picture, a new, biologically-oriented approach which is ecological- 
