Evening star. [volume] (Washington, D.C.) 1854-1972, 1962-12-06

times more abundant after
spraying than they had been
before.
At other times spraying,
while reasonably effective
against the target insect, has
let loose a whole Pandora's box
of destructive pests that had
never previously been abundant
enough to cause trouble. The
spider mite, for example, has
become practically q worldwide
pest as DOT and other insec-
ticides have killed off Its enc
mics.
In the Shenandoah Valley Of
Virginia, a famous apple-grow-
ing region, hordes of a small
insect called the red-banded
leaf roller arose to plague the
growers as soon as DOT began
to replace Arsenate Of lead. Its
depredations had never before
been important; soon its toll
rose to so per cent Of the crop
and it achieved the status Of
the most destructive pest Of
apples. not only in this region
but throughout much Of the
East and Midwest, as the use
Of DOT increased.
When q wholesale application
Of heptachlor was made to the
farmlandS In Louisiana In 1857,
the result was the unleashing
Of one Of the worst enemies
Of the sugarcane crop-the su-
garcane borer. Soon after the
heptachlor treatment, damage
by borers increased sharply. The
chemical aimed at the fire ant
had killed off the enemies of
the borer.
The same bitter lesson was
learned by Illinois farmers.
After the devastating bath of
dieldrin recently administered
to the farmlands in eastern Il
linois for the control of the
Japanese beetle, farmers dis
covered that corn borers had
increased enormously in the
treated area.
Our Efforts Defied
If Darwin were alive today
the insect world would delight
and astound him with its i'm
pressive verification of his the
cries Of the survival of the
fittest. Under the stress Of in
tensive chemical spraying the
weaker members Of the insect
populations are being weeded
out. Now, in many areas and
among many species only the
strong and fit remain to defy
our efforts to control them.
Before l945 only about a
dozen insect species were
known to have developed re-
siStance to any of the pre-DDT
insecticides. With the new or
ganic chemicals and new
methods for their intensive ap-
plication, resistance began a
meteoric rise that reached the
alarming level Of 1877 species
In 1860. No one believes the
end is in sight. More than 1000
technical papers have now been
published on the subject. The
World Health Organization has
enlisted the aid Of some 500
scientists In all parts Of the
world, declaring that ire
sistance is at present the most
important single problem facing
vector control programmes.
A distinguished British student
of animal populations, DR.,
Charles Elton, has said. I'VE
are hearing the early rumblings
of what may become an ava
lanche In strength"
Although insect resistance Is
a matter Of concern in agri-
culture and forestry. it is in
the field Of public health that
the most serious apprehensions
have been felt. The relations
between various insects and
many diseases Of man is an
ancient one. The list OF dis
eases and their insect carriers,
or vectors. includes malaria and
mosquitoes. typhus and body
lice. plague and rat fleas, Afri-
can sleeping sickness and tsetse
flies, various fevers and ticks,
and innumerable others.
These are important prob
lens and must be met. No re-
sponsible person contends that
insect-borne disease should be
ignored. The question that has
now urgently presented itself
Is whether 1t is either wise
or responsible to attack the
problem by methods that are
rapidly making 1t worse. The
world has heard much OF the
triumphant war against disease
through the control OF insect
vectors OF infection, but II has
heard little Of the other side
OF the story-the defeats, the
short-lived triumphs that now
strongly support the alarming
view that the insect enemy has
been made actually stronger by
our efforts. Even worse, we
may have destroyed our very
means Of fighting.
In the words Of DR.. c. j
BrieJer. Director OF Hollands
Plant Protection Service. TITS
more than clear that we are
travelling a dangerous road. We
are going 10 have TO do some
very energetic research on
other control measures, meas
ures that will have TO be bio