Diflubenzuron was found to inhibit cuticle production in final instar Manduca larvae when fed or applied topically. After topical application of 5μg diflubenzuron to the newly molted 5th instar larvae, the rate of cuticle deposition decreased to only two-thirds of normal thickness. In vitro it inhibited both endocuticle deposition and ecdysterone-initiated pupal cuticle synthesis by the epidermis. Both effects are due to its inhibition (ID₅₀=1.1×10^-9M) of glucose or glucosamine incorporation into chitin.

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Onions attract onion maggots and flies, Hylemya antiqua, for oviposition more when maggots first infest and condition the onions. A Klebsiella sp. responsible for the generation of the attractants from the conditioned onions was isolated. Lab tests on a bacteria-inoculated onion slice incubated for 3 days at 37°C showed good attractancy. The headspace volatiles of the bacteria-inoculated onion were collected on a Porapak column and the constituents were fractionated by liquid and gas chromatography. Mass spectroscopic analysis revealed ethyl acetate, tetramethylpyrazine, n-heptanal and 2-pentanol as the major constituents, in addition to the attractive sulfur-compounds such as dipropyl disulfide and methyl propyl disulfide which were already known. Bioassay with these authentic compounds singly and in mixture at various concentrations proved that ethyl acetate per se was the most attractive against maggots. Tetramethylpyrazine and n-heptanal tripled the attractancy of dipropyl disulfide. Ethyl acetate and tetramethylpyrazine also enhanced the attractancy of dipropyl disulfide for oviposition two to three times. 2-Pentanol, on the other hand, neither attracted maggots and flies nor enhanced the attractancy of dipropyl disulfide.

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The persistence of parathion, methyl parathion and fenitrothion in sea water was measured by an experimental planning method utilizing a L₁₆ (2¹⁵) orthogonal layout. The factor for persistence was statistically analyzed using 5 factors and 2 levels: water quality (river water and sea water), suspended solid (existence and non-existence), temperature (constant room temperature and outdoor temperature), light (light and dark), and vaporization of chemicals (opening and closing of the vessel). In the water environment, the persistence of organophosphorus insecticides was affected mostly by water quality and light, and partially by temperature, but not by suspended solids and vaporization. These phosphorus insecticides were chemically stable even in sea water at pH 8.3. From an experiment on persistence of organophosphorus insecticides in the mixture or the boiled sample of river- and sea-water, it was concluded that the microbial degradation of phosphorus insecticides in sea water was largely suppressed by high salt concentration. The residual amount of fenitrothion in sea water sampled near the air-sprayed area was more than that in river water.

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Two-generation reproduction tests with teratology studies were done with 4, 5, 6, 7-tetrachlorophthalide (fthalide) in Wistar-Imamichi rats. Animals received 0, 0.1 or 1.0% fthalide in a pulverized diet during the entire study. Throughout the experimental term there were no toxic symptoms or mortality related to the ingestion of the compound. No significant changes were found in the bodyweight, food or water consumptions. Fthalide ingestion did not affect reproductive parameters such as mating, fertility, and parturition indices or average litter size. In a teratology study done on F1b and F2b litters, neither fetotoxic nor teratogenic effects were observed.

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The degradation of [aniline-U-¹⁴C] mepronil in a volcanic ash soil (Aso) and an alluvial soil (Kikugawa) was studied under submerged conditions in the laboratory. After incubation of the soil containing ¹⁴C-mepronil at 1.6ppm in a biometric flask in the dark at 29°C for 80 days, the soil was sequentially extracted with methanol/water (2/1) and acetonitrile (extractable) and the residue (bound) was extracted with dichloromethane after treatment with 12 N-NaOH/methanol (1/3) at 70°C for 2hr. Mepronil was the major constituent in both extracts. Its half-life was 46 and 50.5 days in Aso and Kikugawa soils, respectively, but counting mepronil bound in soils, the half-life extended to 117 and 120 days, respectively. The degradation products were tightly bound on soil particles and the extractable amounts were small. Four of the 7 products were identified as 1-hydroxy-3-oxo-2-(3′-isopropoxyphenyl) isoindoline, 3′-isopropoxy-2-hydroxymethylbenzanilide, 3′-hydroxy-2-methylbenzanilide and 3′-(1-hydroxymethylethoxy)-2-methylbenzanilide, indicating that hydroxylation occurs on the three positions of the mepronil molecule.

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The DTA diagram of Sumithion in the air shows three exothermic peaks at 150-190°C (I), 210-235°C (II) and 270-285°C (III), while the DTA diagram of Sumithion in the nitrogen atmosphere shows two exothermic peaks corresponding to the peaks (II) and (III) in the air. These peaks are attributed to the following reactions. Peak (I) Sumioxon formation with sulfur dioxide gas evolution, Peak (II): Dimethyl sulfide gas evolution through S-methyl-Sumithion and polymetaphosphate formation, Peak (III): Carbonization of phenolic rings and evolution of dimethyl sulfide, dimethyl disulfide and ethane gases. Some amount of S-methyl-Sumithion was produced after heating. Sumithion up to 193°C both in the air and in the nitrogen atmosphere, although no DTA peak attributable to the isomerization reaction of Sumithion to S-methyl-isomer was observed. The reaction of Sumithion with oxygen was found to be diffusion-controlled. The heat of the formation of sumioxon is calculated to be 170-180kcal/mol.

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Many N-substituted 3, 4, 5, 6-tetrachlorophthalamic acids and their related compounds derived from phthalic acid derivatives were prepared, and their inhibitory activity to rice bacterial leaf blight were tested. Of these compounds, N- (2, 3-dichlorophenyl)- and N-(1-naphthyl)-3, 4, 5, 6-tetrachlorophthalamic acid showed the most potent activity.

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Several biochemical factors responsible for organophosphate insecticide resistance in the housefly were investigated. Although no significant difference in substrate specificity for cholinesterase from resistant and susceptible housefly strains was detected, the enzyme from the resistant strains was 5 to 29-fold less sensitive to inhibition depending upon the inhibitor, than the cholinesterase from the susceptible strain. GSH S-transferases and a carboxylesterase which hydrolyzes malathion were also found to be responsible for resistance. The inter-strain difference in GSH S-transferase activity was the result of larger amounts of the same transferase in the resistant strains. On the other hand, the MFO system, cytochrome P-450, phosphorotriester hydrolase, and α-NA carboxylesterases were not involved in resistance. The in vitro degradation of malathion demonstrated that the compound was degraded mainly via carboxylesterase activity which was located in the nuclei, the mitochondria, and the microsomal fractions, and via GSH S-transferase in the soluble fraction. It was possible to account for the cross resistance and the level of resistance in the housefly strains evaluated by the combination of resistance mechanisms.

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Intake and palatability of 0.375-1.5% thallous nitrate solutions (sweetened with 7.8% sucrose) for rats and mice were measured with an electronic drinkometer in a one-hour test. Mortality was observed for 10 days following the test. The mice preferred the sweetened 0.375 and 0.75% thallous nitrate solutions to plain water; the preference values were 5.4 at 0.375% and 4.7 at 0.75%. Lick counts by mice showed a four-fold increased following the addition of sucrose to 0.75% thallous nitrate. 100% mortality was obtained with sweetened thallous nitrate solutions at 0.375, 0.75, and 1.5%. Licks by rats at 1.5% concentration were markedly less ferequent and total counts in both test solutions decreased to about one-ninth of the total counts in control test solutions. No mortality was obtained at any concentration of thallous nitrate; none of the test animals consumed a lethal dose even a sweetened 0.375% thallous nitrate solution.

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The photodecomposition rate of phenylphosphonic acid (PPA) in water solutions varied according to the wavelength of UV light irradiated and was slower under sunlight than under UV light with a maximum wavelength of 254nm. By irradiation with the UV light, 97% of PPA in a water solution at the rate of 100ppm disappeared after three days and 86% of that was converted to phosphoric acid after sixty days. Two compounds detected as intermediates of the photodecomposition reaction were assigned to be the stereoisomers of 4-hydroxybicyclo[3.1.0]hex-2-en-6-ylphosphonic acid which may be formed by the addition of water to the phenyl moiety of PPA. Decomposition of PPA as thin film on a glass plate under UV light with the maximum wavelength of 254nm was much slower than in the water solution.

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This report presents the modified method of our previous paper where methyl bromide (MB) liberated from crops by Malone's method was determined with glc after its derivatization to O, O-diethyl S-methyl dithiophosphate with ammonium O, O-diethyl dithiophosphate. In the previous procedure, using acetone, it was proved that O, O-diethyl S-methyl dithiophosphate was produced by means of sunlight irradiation or occasionally by means of heating in the absence of MB. Hence, by using N, N-diethyl formamide instead of acetone it became possible to avoid this undesirable phenomenon. Recoveries were 75.7-87.0% from hay and eggplant fortified at a level of 0.05-0.25ppm, with a detection limit of 0.0003-0.002ppm. This method made it possible to eliminate the drying tube from Malone's apparatus, and also possible to carry out the operation without excessive cooling of the MB scavenge reaction tubes.

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Development of resistance to organophosphorus thiolate (PTL) fungicides in Pyricularia oryzae in the field was monitored. In 1977, development of moderate resistance was demonstrated by the frequency distribution of sensitivity to IBP evaluated by minimal growth-inhibitory concentration (MIC) among field-isolates from Toyama prefecture, as compared with stock strains isolated before PTL fungicides were practically used. Discrimination of the moderately resistant (MR) strains from normal strains, however, was difficult with the evaluation of MIC. The discrimination was achieved by evaluation of radial growth of mycelia on PSA amended with IBP or by testing sensitivity to synergistic fungicidel action of IBP and a N-phenylphosphoramidate (PA) by the crossed paper technique. Both PTL-MR isolates, which were frequently found, and a PTL-resistant (PTL-R) isolate, which was rarely found, were resistant to the synergistic action. PTL-R and PTL-MR mutants obtained by in vitro selections and the PTL-R isolate were more sensitive to PA than normal strains, while PTL-MR isolates were not. The PTL-R isolate therefore seemed similar to PTL-R mutants, but the PTL-MR isolates differed from the PTL-MR mutants. No lesion was found from which both PTL-sensitive and PTL-MR strains were isolated.

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Residual levels of pesticides, MEP, MPP and PAP, in parts of mulberry stumps were determined by means of glc. Ten days after application, a high concentration of all chemicals remained in the bark: MEP 66-790ppm, MPP 52-120ppm and PAP 58-347ppm. Several ppm of these pesticides also remained in the wood. Only a small quantity, 0.14-1.08ppm of MEP remained in the pith. Silkworms can be reared normally on mulberry leaves harvested from the pesticide-treated stumps, but a slightly reduced cocoon weight was noted case of MEP and MPP-treatment.

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A single oral dose of ¹⁴C-ferric methanearsonate (20mg/kg) was administered to pregnant Wistar rats on days 11 and 19 of gestation, and the placental transfer of radiocarbon was periodically evaluated up to day 20 of gestation by whole-body autoradiography and radiometry. Transplacental bioaccumulation of radiocarbon occurred only in the matured fetuses in the late gestational stage around parturition, whenever the dosage had been administered later than the embryonic stage during the gestational period. Similar to adult rats, the blood was the primary site of the body burden, and the radioactive substance responsible for the high affinity to fetal blood was considered as dimethylarsinic acid (cacodylic acid). From the toxicity test data gathered, the observed accumulation of the organoarsenate is considered not to disturb the development of rat embryos.

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The behavior and metabolism of blasticidin S and methoxyphenone were studied in the model system to evaluate their safety in the environment. ¹⁴C-blasticidin S was prepared biosynthetically by the producing organism, St. griseochromogenes. Prior to the study on the metabolism of blasticidin S, its site for accumulation was investigated to find that the antibiotic was mostly located on the surface of the rice plant after foliar application. From the wound or infected part, however, blasticidin S was uptaken by the plant and was translocated mainly to the upper part. The compound on the plant surface was decomposed by sunlight and gave rise to cytosine as the main degradation product. In the plant the antibiotic was metabolized gradually, and a small amount of cytomycin and trace of others were produced. A considerable quantity of blasticidin S was supposed to fall on the ground by rainfall besides those fallen when it was sprayed, which was found to be bound firmly onto the soil surface. From ¹⁴C-blasticidin S-treated soil significant liberation of ¹⁴CO₂ was observed, and several microbes usually inhabiting in the paddy field were involved in lowering the biological activity of blasticidin S. Among the microbes, an isolated fungal strain, which was identified as Asp. terreus, caused marked inactivation by converting the antibiotic to deaminohydroxy-derivative. The enzyme was isolated and characterized to be a new aminohydrolase. Methoxyphenone was readily metabolized in the treated plants, in soils, and by rats. Products oxidized at 3 or 3′-CH₃, a 4-desmethyl metabolite, and a reduced one at carbonyl group were identified as metabolites in common by using ¹⁴C-methoxyphenone labeled at carbonyl carbon. There were observed some differences in metabolism in each system, e. g., ¹⁴CO₂ was liberated only from a treated soil. An isolated bacterium (Bacillus sp.) capable of degrading methoxyphenone showed a remarkable activity to phosphorylate phenolic OH of the desmethylated metabolite.

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The metabolism of trans- and cis-permethrin are studied in rat, cow and insects. The studies utilized eight ¹⁴C-permethrin preparations. Permethrin isomers are rapidly metabolized both hydrolytically and oxidatively. The ester hydrolysis are rapid with trans- than with cis-permethrin from all species. There are species-dependent differences in the preferred sites for hydroxylation of the permethrin isomers and in the conjugation reactions of the metabolites. The parent compound, free metabolites and their conjugates are quickly eliminated from mammals. Decamethrin metabolism in rat is on analogy wtih the metabolism of [IR, cis] permethrin. The cleavage of the decamethrin ester group leads to release of cyanide which is converted mainly to thiocyanate and a small amount of 2-iminothiazolidine-4-carboxylic acid. Allethrin, tetramethrin, resmethrin and furamethrin are included in β-cyclodextrin (CD) in 1:2 molar ratio. The included pyrethroids are stabilized for photodecomposition. The CD inclusion retardes th photochemical attack of the acid moiety for allethrin and of the alcohol moiety for resmethrin. Cochromatographic comparison of the synthetic compounds with the eight metabolites of rotenone confirmed the stereochemical configurations for the metabolites. 2-O-Demethylation is established as a new detoxification mechanism. All the four stereoisomers of natural rotenone and its O-demethyl derivatives are synthesized by the reaction of rotenone and d-epirotenone with one to three equivalents of boron tribromide followed by recyclization of the E-ring. The structure-biological activity relationships of 63 rotenone derivatives including 40 new ones are studied. High potency appears to be associated with the presence of ABCD ring system with the cis-6aβ, 12aβ-B/C ring juncture as in rotenone. Various types of modification of this juncture result in the diminished potency.

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