Preliminary tests with certain N-substituted benzamines for synergistic action in pyrethrum fly sprays


Material Information

Preliminary tests with certain N-substituted benzamines for synergistic action in pyrethrum fly sprays
Physical Description:
3 p. : ; 27 cm.
Mitlin, Norman
Gertler, S. I
Gersdorff, W. A ( Wilbur August ), b. 1894
United States -- Bureau of Entomology and Plant Quarantine
U.S. Dept. of Agriculture, Agricultural Research Administration, Bureau of Entomology and Plant Quarantine
Place of Publication:
Washington, D.C
Publication Date:


Subjects / Keywords:
Flies -- Control   ( lcsh )
Pyrethrum (Insecticide)   ( lcsh )
Benzamide   ( lcsh )
federal government publication   ( marcgt )
non-fiction   ( marcgt )


General Note:
Caption title.
General Note:
General Note:
"November 1951."
Statement of Responsibility:
by Norman Mitlin and S.I. Gertler and W.A. Gersdorff.

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 030338078
oclc - 780445605
System ID:

Full Text

Nvember 1951

United States Department of Agriculture
Agricultural Research Administration
Bureau of Entomology and Plant Quarantine


By Norman Mitlin and S. I. Gertler,
Division of Insecticide Investigations, and
W. A. CGersdorff, Division of Stored Product Insect Investigations

In a previous publication in this series (E-805) the authors re-
ported that certain N-substituted benzene sulfonaiiides had been found to
show promise as synergists for pyrethrum in fly sprays. Further studies
have now shown that several N-substituted benzamides also act as pyreth-
rum synergists. These compounds are characterized by the general formula

II xR'
C6H5 C --NNR,

R may be either hydrogen or an alkyl group, and R' may be hydrogen, an
alkyl, or a cyclic group. These groups may be either substituted or un-
substituted. The compounds were generally prepared by reacting benzoyl
chloride with an amide under suitable conditions.

The compounds were incorporated in sprays alone and in mixtures
with 1 mg. of pyrethrins per milliliter. Since their solubility in
refined kerosene was low, an equal amount of acetone was used as an
auxiliary solvent. Varying concentrations of the adjuncts were used.
Pyrethrumn standards, in which pyrethrin I and cinerin I comprised 54
percent of the total pyrethrins, were also prepared in the same solvent
mixture at concentrations of 1 and 2 mg. per milliliter.

The tests were made by the Campbell turntable method on adult house
flies (Kusca domestic L.) reared by standard laboratory procedure.
Since 1kn-down is increased by the addition of acetone, it was not er
timated. Mortality only was determined for each spray. Approximately
100 flies averaging 3 days of age were used in each test. The mixed
sprays were replicated four times, the sprays containing the adjunct
alone but twice. Since it was necessary to make the tests in a number
of different series, the two standard pyrethrimi sprays were included in
each series as a base of reference.


To avoid reportinE many series and to put the results on a com-
parable basis, the following procedure was followed: The mortalities
obtained for the st-andard sprays in each series were plotted on log-
probability paper and straight lines drawn. From these lines the py-
rethrins equivalent was estimated for each mixed spray. These figures
may be considered as expressions of relative toxicity, since they are
all compared with the concentration of 1 mg. of pyrethrins per milli-
liter. These results are asseribled in table 1.

At the concentrations used, the adjuncts alone caused negligible
mortality. For 11 of the mixtures the increase in toxicity was signifi-
cant. Synergism was therefore shown in these mixtures. The effective
adjuncts were as follows:

N, N-Dicyclohexylbenzamide 2' -Bromobenzanilide
N,N-Diisopropylbenzamide 2' -Chlorobenzanilide
N, N-Dipropylbenzamide 2 ,5' -Dichlorobenzanilide
N-Isopropylbenzamide o-Benzanisidide
N-(1-Methylamnyl)benzamide o-Benzophenetitide

In mixtures containing the following adjuncts the increase in tox-
icity was at the borderline of significance: N,N-Diethylbenzamide,
N-propylbenzamide, and 9-benzoylcarbazole.

- 3 -

Table l.--Toxicity to house flies of space sprays containing certain
benzamides in mixtures with 1 mg. of pyrethrins per milliliter

Pyrethrins Pyrethrins
equivalent equivalent
Material Concentration of required
mixture to show

Benzamide 10 o.84 1.54
Benzamide, N-benzoxy- 10 .81 1.35
N-sec-butyl- 20 1.15 1.38
N,N-dicyclohexyl- 20 2.15 1.39
N,N-diethyl- 20 1.47 1.51
N,N-di(2-ethylhexyl)- 20 >2 -
N,N-diisopropyl- 20 1.84 1.38
N,N-dimethyl- 20 1.05 1.38
N,N-dipropyl- 20 2 -
N-ethyl- 20 1.09 1.51
N-isopropyl- 20 1.59 1.38
N-(l-methylamyl)- 20 1.814 1.35
N-propyl- 20 1.4i6 1.51
Benzanilide,N-benzyl- 20 1.71 1.39
2 '-bromo- 20 >2 1.36
3'-bromo- 20 1.07 1.30
4' -bromo- 10 .99 1.3C
2 '-chloro- 20 1.74 1.54
3'-chloro- 20 1.10 1.54
h '-chloro- 10 .80 1.36
2,,5'-dichloro- 10 1.66 1.39
N-l-naphthyl- 10 .83 -
N-2-naphthyl- 10 .50 -
3'-nitro- 20 .81 1.30
4'-nitro- 10 .86 1.30
N-phenyl- 10 .51 -
2'-phenyl- 5 .64 -
o-Benzanisidide 20 1.90 1.35
Benzoic acid,p-benzamido,ethyl ester 20 .86 1.30
o-Benzophenetitide 20 3.0C4 1.35
p-Benzophenetitide 20 1.2C 1.39
Carbazole,9-benzoyl- 20 1.2, 1.30

c, : o OF FiLORIOA

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