Evening star., 1950-04-14
Wide Advance Reported
In Mons War on Buos
New Mite Poison Comparable
Z In Efficiency to DDT
By Thomos Z. Henry

A major advance in mans war on bues
"A mite poison comparable in efficiency
10 DDT as an insect poiSon-hAS been
reported to the American Association for
the Advancement Of Science here
Mites are arachids. closely related 70
spiders. which occur in many hundreds
OF varieties and often are immune to the
most potent insect poisons. Most Of
them are close to microscopic In sixe
They are serious plant pests but. In the
balance Of nature, usually are kept under
control by the predatory insects.
The advent OF DDT and similar ex-
tremely potent insecticides. by which
the mites are unaffected. has removed
their natural enemies and given them
room for enormous expansion. Event
ually they might become almost 40 de-
structive Is the insects themselves
Chemicals Developed.
A group of workers headed by Or. Oil
yer Grummitt Of Western Reserve Uni
versity in Cleveland has developed q
series OF chemicals. so-called alkylcar-
hinols, which are specific against the
mites themselves, apparently nonpoison-
Gus In reasonable amounts to animals
birds or to the general insect kingdom.
ton. There is no plant damage under
ordinary spraying conditions. 1t has been
determined. The poisonS apparently kill
the mites on contact. They have proved
effective against such varied organisms
two-spotted mites.
These poisons, according to the report
In Science. the associations oficial Or
hM N,Fa - -, l..
ton lots. No harmful effects have been
observed on persons working with the
substances over a period Of several
months. The alkylcarbinols. 1t has
been determined by exhaustive tests
with rats over several months are no
more poisonous to warm -blooded animals
than are DDT and related compounds
The Western Reserve workers believe
that eventually it will be found less
poisonous.
A potential major advance against
rabies-the first successful cultivation OF
the rabies virus in incubated eggs-has
just been reported through the Public
Health Service.
Rabies vaccines. Of which enormous
quantities are used throughout the coun-
try. are produced by growing the virus
responsible for the malady and then
killing it, At present this requires the
use Of large numbers OF animals. For
human vaccine the virus is obtained
from the brains of rabbits. The animals
are first infected and after an appro-
pirate period their brains are ground up
and the virus killed. Such q vaccine Is
not entirely safe because Of the danger
Of bad reactions from the brain tissue
Many communities now require the
annual vaccination of all dogs. The
material for this use is obtained from
the brains OF infected sheep and horses
This permits the vaccines to be produced
in large quantities but they would not
be considered safe for use with humans
Output Slow and Costly.
Production Of vaccines with animals
always is slow and rather expensive.
One Of the major advances In pre-
ventive medicine OF this generation has
been the technique of growing viruses
In Matching eggs. usually chicken eggs.
In this way, for example. typhus vac
cineS IN limitleSS quantities were pro-
duced during the war. The rabies virus
has been strangely refractory up to date.
Its cultivation in eggs finally has been
accomplished. according to the Public
Health Service announcement, by Drs.
H. NJ. Powell and c. G. Culbertson Of
the Lilly Research Laboratories of In
dianapolis. They succeeded with duck
eggs where everybody had failed with
chicken eggs.
Vaccine made from this virus has
been completely effective in mouse pro-
lection tests. The way may be opened
for limitless quantities Of cheap vaccine.
Ouae%;nne nnd Ane,ua.e