1_ STA March 1952 E-837 United States Department of Agriculture Agricultural Research Administration Bureau of Entomology and Plant Quarantine PRELIMINARY TESTS WITH CERTAIN m-NITROBENZAMIDES FOR SYNERGISTIC ACTION IN ALLETHRIN FLY SPRAYS By S. I. Gertler i/ W. A. Gersdorff,-' and Norman Mitlini-' In previous publications in this series (E-805, E-828) the authors reported that certain N-substituted benzenesulfonamides and certain N-substituted benzamides had been found to show promise as synergists for pyrethrum fly sprays. In further research the action of certain m-nitrobenzamides in mixtures with allethrin, a synthetic insecticide, was examined for synergistic effect. These compounds are characterized by the general formula NOo \! v o / OK, R and R' cover a wide range of chemical groups. All the compounds were prepared by reacting m-nitrobenzoyl chloride with various amines under suitable conditions. The compounds were incorporated in sprays alone and in mixtures with 0.5 mg. of allethrin per milliliter. Since their solubility in refined kerosene was low, an equal amount of acetone was used as an auxiliary solvent. With one exception the concentration of the adjuncts was 20 mg. per milliliter. Allethrin standards were also prepared in the same solvent mixture at concentrations of 0.5 and 1 mg. per milliliter. The allethrin used in all tests was from a distilled sample of high purity. The tests were made by the Campbell turntable method on adult house flies (Musca domestica L.) reared by standard laboratory pro- cedure. Since knock-down is increased by the addition of acetone, it was not estimated. Mortality only was determined for each spray. 1/ With the Division of Insecticide Investigations. 2/ With the Division of Stored Product Insect Investigations, formerly the Division of Control Investigations. - 2 - Approximately 100 flies averaging 2 days of age were used in each test. The mixed sprays were replicated four times, the sprays containing the adjuncts alone but twice. Since it was necessary to make the tests in a number of series, the two standard allethrin sprays were included in each series as a base of reference. To avoid reporting many series and to put the results on a comparable basis, the following procedure was used: The mortalities obtained for the standard sprays in each series were plotted on log-probability paper and straight lines were drawn. From these lines the allethrin equivalents for the mixed sprays were estimated. Since these figures are all com- pared with the concentration of 0.5 mg. of allethrin per milliliter, they give, when multiplied by 2, expressions of relative toxicity. These results are assembled in table 1. Estimates of the increase in the mean equivalents required to show significant increase in toxicity were made by an analysis of variance of the logarithms of the individual equivalents. At the concentrations used, the adjuncts alone showed negligible mortality. For 10 of the mixtures the increase in toxicity was significant. Synergism was therefore shown in the mixtures. The effective adjuncts are as follows: N,N-Dibutyl-m-nitrobenzamide N,N-Diethyl-m-nitrobenz amide N,N-Diisobutyl-m-nitrobenz amide N,N-Diisopropyl-m-nitrobenz amide N,N-Dimethyl-m-nitrobenz amide N,N-Dipropyl-m-nitrobenz amide N-Isobutyl-m-nitrobenz amide N-Isopropyl-m-nitrobenz amide 1 -m-Nitrobenzoylpiperidine m-Nitro-N-propylbenzamide -3- Table 1. --Toxicity to house flies of space sprays containing certain benzamides in mixtures with 0.5 mg. of allethrin per milliliter. Concentration is 20 mg. per ml. unless otherwise indicated. Material Allethrin equivalent of mixture Allethrin equivalent required to show synergism Benzamide, N-amyl-m-nitro- N-benzyl-m-nitro- N-butyl-m-nitro- N -sec- butyl - m - nit ro - N-cyclohexyl-m-nitro- N,N-dibutyl-m-nitro- N,N-dicyclohexyl-m-nitro- N,N-diethyl-m-nitro- N,N-diisobutyl-m-nitro- N,N-diisopropyl-m-nitro- N,N- dimethykm-nitro- N, N-dipropyl-m -nitro- ns-isobutyl-m-nitro - N-isopropyl-m-nitro- N-methyl-m-nitro-i/ m-nitro-N- propyl - Benzanilide, 2'-chloro-3-nitro- 3'-chloro-3-nitro- 3-nitro- Hydrazine, 2 -m-nitrobenzoyl-1 -phenyl - Morpholine, 4-m-nitrobenzoyl- Piperidine, 1-m-nitrobenzoyl 0.678 0.731 .509 .731 .563 .797 .420 .797 .600 .631 >1.5 .797 .619 .631 .665 .610 .995 .631 >1.5 .797 .654 .610 >1.5 .797 1.003 .797 .726 .610 .515 .610 .666 .610 .542 .631 .435 .631 .570 .631 .357 .731 .526 .731 .690 .610 1/ 10 mg. per ml. UNIVERSITY OF FLORIDA I 3 1262 09239 6455