June 1949 -,
TAT PLANT BOAR Jnited States Department ,,.'iculture
STATE Agricultural Research Ad-.i,'itation
Bureau of Entomolo r ai Plant 1 janti.I.
LABCRATO',RY TZSTS 0;:. TOXTCITY ..,. , .- .
TO THE E'E ,.. .i* :.. A. ._-
By S. I. Gertler, Division of Insectic' Invest ions, ; ,
D. D. Questel and R. V. Connin, Division of ea and e ..-.
Twenty-one orc:anic compouiis were tes-..j for oxici' to newt
hatched Eur-:pean corn borer larvae ji'L...j, L. (. A)) a r ...-.,
Ohio, from -'. t'u-c,,h 1947. esc ccmp, L.'> are a ce. re-
lated. They are all derived from p.e'Lfr-,dr'.-.e' ,- most of ..t re
prepared b:' .ei.cting phenylhydrazi-ie with an acid or acid chl.i ". They
may be reprec.,1 9d by the general fo-,,,la ., .N "
In each cvsa R is an acyl group, which is derived from an acid. R'
is hydrogen except in one compound, '.',,ere it also is an ,cyl . In
most cases where there is only one acyl substituent, the -'....pound 'i:. named
as a phenylhydrazide of the acid. The cor'r:rurd that has an acyl substit-
uent on each nitrogen is named as a phe.iylhydrazine. T.e et'.Ld:,:! /l de-
rivative, which is derived from an ester, is also r-id as a *-.ihe..y1.ydrazine,
The larvae used in the tests were obtairi-id from et .1 i moths
reared in the laboratory from field-collected borers. 'J s.al.y the borers
were retained in cold storage for se,'r-,al mont':s in orJer to satisfy their
diapause requirements and thus provide a continuous '-..-p y of moths as
needed. Male and female moths were conf`jz. in a lL.ica wire (5
meshes to the inch) oviposition cage 1 foot '. ... 9 inches in diameter.
To prevent the escape of the moths from the c;.e, the side ",.'1ll1 was
covered with coarse cheesecloth, which is not a a, ....le --. face for
oviposition. The top of the cage was 1:.-- with a sheet f .. ci paper,
and the moths readily oviposited on this s., face through the wire mesh.
The cage was placed under a bell jar to ins.-i1 the high .1. iity that is
favorable to oviposition,
The paper with the attached egg -asses was remov.3 -- 'r :l. cut into
small sections, each containing an egg mass. 'e'-. mas. N-. ere V.en
placed in a gallon earthenware jar containing moist blotti.:-paper and
allowed to incubate. From 20 to 100 eg- masses in .,e 1ib7': -,._he,:-?r stage,
which just precedes hatching, were required daily when the C:'i-.. :als were
If Tests with the same group of conrnunds ;-_aiist other insects have
been reported in processed publication E-76", entitled "Prell.l.ry
tests of certain phenylhydrazides as insecticides. G-. T Bott-er,
A. P. Yerrington and S. I. Gertler. 10 pp. March 1)4-.
JUL no -
The sprays were prepared by grinding with a stirring rod 0.25 gram
of the compound in a beaker containing a little water plus all the wetting
agent, sodium mnonosulfonate of butylphenylphenol (Areskap), required to
furnish a dilution at the rate of 1 gram of wetting agent to 2,000 cc. of
water in the completed spray. After the material had been finely ground,
enough water was added to bring the dilution of the compound to the rate
This preparation was sprayed thoroughly upon fresh green leaves with
a small atomizer connected to an air-pressure tank fitted with an auto-
matic air regulator set for 10 pounds' pressure. Cauliflower leaves,
which do not decompose readily, and upon which the borer thrives, were
used as the feeding medium. As soon as the surface water had evaporated,
the leaves were made into small rolls and one role inserted into each
test tube containing one or two corn borer egg masses in the blackhead
stage. A cotton-filled cloth stopper was used to plug the mouth of the
Observations were made daily. At the end of the test period records
were made of the dead and living larvae, the condition of the leaves, and
the amount of feeding.
The number of larvae used at each application at each concentration
ranged from 34 to 206, and averaged 121. All the larvae were given an
opportunity to feed for 48 hours before mortality readings were taken.
The amount of feeding by the larvae varied from none, where mortalities
were high, to much, where mortalities were low. In comparable checks
with untreated leaves, which were included in all tests, mortalities
ranged from 0.4 to 1.0 percent. Compounds that gave high mortalities were
retested at lower concentrations. Results of these tests are given in
Of the 21 compounds 13 gave 90 percent or higher mortality when
tested at 4 pounds per 100 gallons of water. Eight compounds continued
to give this mortality when tested at the 2-pound concentration. Three
of these compounds gave kill above 90 percent when tested at 1 pound per
100 gallons of water. Three of the phenylhydrazides showed no appreci-
able mortality when tested at the 4-pound rate. Results of these tests
indicate that the phenylhydrazide group is quite toxic to newly hatched
corn borer larvae.
Amon the compounds most toxic at 1 pound per 100 gallons are the
phe iylhydrazides of some of the isoaliphatic acids. Of this group the
phe.-ylhydrazide of the 4-carbon isobutyric acid is the most toxic. The
5-and 6-carbon derivatives, isovaleric and isocaproic, are somewhat less
toxic. Among the phenylhydrazides of the straight-chain aliphatic acids,
that of the 5-carbon valeric acid shows the most toxicity, whereas those
of the lower acids butyric, propionic, and acetic show practically no
toxicity at this concentration. The long-chain stearic acid is nontoxic.
The phernylhydrazide of benzenesulfonic acid is one of the two most toxic
compounds, whereas the derivative of the higher homolog, toluenesulfonic
acid, is less toxic and that of sulfonic acid much less.
Amon- the phenylhydrazides of the aromatic acids, that of cinnamic
acid, which has an unsaturated side chain, is most toxic. Benzoic and
1-chlorobenzoic acid phenylhydrazides are somewhat less toxic and all
the other su-bstituted benzoic acid derivatives Lave little toxicity.
Table 1.--Toxicity of cauliflower leaves ,. .,ea with different
henyrlhydrazides to newly hatched }tu-opean corn borer larvae
in laborator:.- tests.
Percent mortality at indicated
Phenylhydrazide strength per 100 gallons
4 pounds 2 pounds 1 pound
B.anzenesulfonic acid 100 100 99
Isobutyric acid 100 100 99
Isocaproic acid 100 100 91
Isovaleric acid 100 100 80
Cinnamic acid 95 98 65
Toluenesulfnnic acid 10G 97 60
Valeric acid 100 100 44
2-Chlorobenzoic acid 100 66 42
Benzoic acid 94 74 34
Sulfonic acid 100 93 18
Phenrrlacetic acid 90 59 10
Butyric acid 95 60 2
Acetic acid 95 21 3
Propionic acid 78 -
3,4-Dichlorobenzoic acid 35 -
Hydrazine, l-ethoxalyl-2-phenyl- 34 -
R-:Titrobenzoic acid 23 -
2,4-Dichlorobenzoic acid 21 -
m-Nitrobenzoic acid 3 -
p-Chlorobenzoic acid 2 -
Stearic acid 0 -
UNIVERSITY OF FLORIDA
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