The Indianapolis times. [volume] (Indianapolis [Ind.]) 1922-1965, 1934-06-06
Today S Science
BY DAVID DIETZ

THREE bureaus of the United States department
Il of agriculture have embarked upon an enlarged
program Of research to find a substitute for lead
arsenate and other poisonous sprays now in general
to protect fruit and vegetables from insect pests
1t is well known fact that many sprays par
tculary the arsenicals, leave residue which pre-
SentS a health hazard. The department is n
forcing strict regulations on spray removal in order
to protect consumers. Il is felt, however that the
development of harmless Insecticides would prove a
better solution of The problem
The three bureaus which will engage in the new
program the bureau of entomology the bureau
of chemistry and soils and the bureau of plant in
dustry. The work will be co-ordinated under the
direction of DR.. E. N. BreSsman, formerly of the
Oregon agricultural experiment station.
An important part of the program will be the
field testing of several organic materials such as
rotenone pyrethrum and nicotine which have
shown promise as substitutes for lead arSenate.
These compounds are believed to be harmless to hui
man beings when present in the concentrations in
which they would be found on harvested fruit.
Laboratory tests also to be carried of a
great variety of other substances which might prove
useful as insect killers.
TINE entomologists will also experiment Wit.
methods which might be used to replace
part, the spraying of fruit trees. One such approach
to the problem is orchard sanitation"
number of practices including the general
cleaning up of orchards during the winter, the band
ing of trees to collect worms and the early picking
of fruit, known to be of value in controlling the
cooling moth. 1t is believed that general extension
spraying.
The New York agricultural experiment station
has found that certain types of traps which
bright light to attract the moths have proved of
siderable value. The scientists hope that they
increase the efficiency of these traps and at the
same time reduce the cost of operating them.
1t is also planned to attack the cooling moth by
means of biological control" There is tiny wasp
like insect known as the "trichogramma minutum"
1t has the strange habit of laying its eggs
within the eggs OF other insects.
This insect has proved useful in the fight against
certain other pests and is hoped that it may prove
efficient in the battle against the cooling moth.
nNE of the most important phases of the entire
" investigation is to determine the effect upon
higher animals of various organic compounds which
might be used to kill insects.
Obviously, there is no point to replacing ar
sencals with compound which is equally dan
gerous to humans or even more dangerous.
Scientists have been working for some time
the formation of synthetic organic compounds which
might take the place of arsenic.
Among the compounds under consideration
is a combination of nicotine and bentonitt. This
compound is not soluble in water and so would not
be washed easily from the fruit by rains. Prelimi
nary laboratory tests give hope that this compound
may be useful against the coding moth
The bureau of plant industry is experimenting
with types of tobacco which are richer in nicotine
than those commonly grown for smoking.
The bureau is also experimenting with pyreth-
rum plant which possesses insectcide properties.
Another plant being studied is weed which is
common in the southeast. It's scientific name is
"cracca virginiana" but it is popularity known
devils Shoestring This weed is believed to be
possible source of rotenone and related substances
which are toxic to insects.