15. Nature Fights Back
TO HAVE RISKED s o much in our efforts to mold nature to our s atis faction and yet to
have failed in achieving our goal would indeed be the final irony. Yet this , it s eems , is our
s ituation. The truth, s eldom menti oned but there for anyone to s ee, is that nature is not s o
easily molded and that the insects are finding ways to circumvent our chemical attacks on
the m.
‘The ins ect world is nature’s mos t as tonis hing phenomenon,’ s aid the Dutch biologis t C. J.
Briejèr. ‘Nothing is impossible to it; the most improbable things commonly occur the re. One
who pe netrates deeply into its mys teries is continually breathles s with wonder. He knows that
anything can happen, and that the completely impos s ible often does .’ The ‘impos s ible’ is now
happening on two broad fronts. By a process of genetic selection, the insects are developing
s trains res is tant to che micals. This will be dis cuss ed in the following chapte r. But the broader
problem, which we s hall look at now, is the fact that our chemical attack is weakening the
defenses inherent in the environment itself, defenses des igned to kee p the various s pecies in
check. Each time we breach thes e defens es a horde of ins ects pours through.
From all over the world come reports that make it clear we are in a serious predicament. At the
end of a decade or more of intensive chemical control, entomologists were finding that
problems they had cons idered s olved a few years earlier had returned to plague them. And new
problems had aris en as ins ects once pres ent only in ins ignificant numbers had increas ed to the
status of serious pests. By their very nature chemical controls are self-defeating, for they have
been devised and applied without taking into account the complex biological systems against
which they have been blindly hurled. The chemicals may have been pretested against a few
individual species, but not against living communities. In s ome qua rters nowadays it is
fashionable to dismiss the balance of nature as a state of affairs that prevailed in an earlier,
simpler world—a s tate that has now been s o thoroughly ups et that we might as well forget it.
Some find this a convenient assumption, but as a chart for a course of action it is highly
dangerous. The balance of nature is not the same today as in Pleistocene times, but it is still
there : a complex, precis e, and highly integrated s ys tem of relations hips between living things
which cannot s afely be ignored any more than the law of gravity can be defied with impunity by
a man perched on the edge of a cliff. The balance of nature is not a status quo; it is fluid, ever
shifting, in a constant state of adjus tment. Man, too, is part of this balance. Sometimes the
balance is in his favor; sometimes—and all too often through his own activities—it is s hifted to
his dis advantage.
Two critically important facts have been overlooked in des igning the modern ins ect control
prog rams. The first is that the really effective control of ins ects is that applied by nature, not by
man. Populations are kept in check by s omething the ecologists call the resis ta nc e of the
environme nt, and this has been s o s ince the firs t life was created. The amount of food
available, conditions of weather and climate, the presence of competing or predatory species,
all are critically important. ‘The greatest single factor in preventing ins ects from overwhel ming
the res t of the world is the internecine warfare which they carry out among themselves,’ said
the entomologis t Robert Me tcalf. Yet mos t of the chemicals now us ed kill all insects, our friends
and enemies alike.