Dealing with the control measures against insect pests applied during the Edo Period, the present paper gives mainly a historical review of protection and eradication methods, and a list of both organic and inorganic materials used for the purposes is attached. It also mentions how Anguilla japonica TEMMINCK et SCHLEGEL (Anguilidae) were widely used to control insect pests, as well the origin and process of dissemination of the “oil dropping method” applied throughout the country. Reference is made to the latter, which had been the most effective way of leafhopper and planthopper control for nearly 250 years, by quoting Chinese literature to explain that it was not a Japanese idea originally but developed from practical knowledge introduced to Japan from China.

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This review summarizes recent research on the metabolism of pesticides by GSH conjugation, the role of this reaction in pesticide selectivity in mammals and plants, and characteristics of GSH S-transferases. GSH conjugation occurs with organophosphorus insecticides, γ-BHC, organothiocyanate insecticides, s-triazine herbicides, thiocarbamate sulfoxides, fluorodifen, EDB and monofluoroacetic acid. GSH S-transferases are widely distributed in mammals, birds, fishes, insects, plants and microorganisms. The highest activity is found in the mammalian liver and microorganisms are low activity. Plant enzymes are very stable. GSH S-transferases from mammals and insects comprise a group of enzymes which have overlapping substrate specificities. Chemical structures possessing an electrophilic center, high SN reactivity, and the reactive center of low electron density can conjugate readily. The formation of a GSH conjugate destroys the biocidal properties of the parent molecule. The function of GSH S-transferases may be regarded as biological protection against electrophilic foreign compounds which have the capacity to bind to biological molecules with nucleophilic centers. The qualitative and quantitative differences in GSH S-transferases distributed in various organisms are closely associated with insecticide or herbicide selectivity and insecticide resistance. Dichloroacetamide antidotes act in corn to induce GSH and GSH S-transferase, resulting in rapid detoxication of thiocarbamate sulfoxides.

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Coronatine is an extracellular toxin produced by Pseudomonas coronafaciens var, atropurpurea (REDDY and GODKIN), the incitant of the chocolate spot disease on Italian ryegrass (Lolium multiflorum LAM.). Coronatine induces the necrosis with chlorotic halo symptoms of the disease in host leaves as well as in nonhosts and thus is nonspecific. Coronatine, at low concentration of 0.3μg to 30μg/ml, also induces marked hypertrophy only on potato tuber tissues. When a potato tuber cylinder was incubated with coronatine before the extensibility measurement, the plasticity was greater than that of the control. The results suggest that coronatine is required to increase the plasticity of the cell wall for cell expansion. These results indicate that coronatine may be characterized as a substance with high auxin-like activity. However, physiological data show that coronatine has a tissue specificity. It is clearly different from IAA. The difference in the tissue specificity strongly suggests that the two substances have different primary site of action. On the other hand, coronatine and IAA have fundamentaly the same final steps in increasing cell size. The steps involve some process which enhance the plasticity of the cell wall. Histological and physiological data show that the most sensitive site for coronatine injury may be in the cytoplasm. On the other hand, coronatine-induced hypertrophy of potato tuber tissues were markedly inhibited by N, N-dicyclohexylcarbodiimide, one of the inhibitors of membrane-bound ATPase. This results suggests a close association between coronatine and membrane-bound ATPase. In addition, coronatine changes the permeability 24 to 48 hours before the development of hypertrophy on potato tuber tissues. Thus, these results suggests that the disruption of the cytoplasm induced by coronatine may be due to secondaly effects brought about indirectly by physiological changes of the plasma membrane.

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Control of perennial weeds, which have recently begun to grow rampantly in the paddy fields, is creating a new problem in rice cultivation in Japan. The present paper intends to give information on the kinds of perennial weeds grown in paddy fields and their distribution, and to review the ecological characters of the major weeds in Japan and the control measures by herbicides. Those presently causing trouble are Scirpus hotarui OHWI, Alisma canaliculatum A. BR. et BOUCHE, Sagittaria trifolia L., Sagittaria pygmaea MIQ., Cyperus serotinus ROTTB. and Eleocharis kuroguwai OHWI. Among them, S. hotarui and A. canaliculatum propagating themselves mainly by seeds, are dominant in North Japan, and others which use tubers for propagation, are widely distributed from the eastern part to western districts of Japan. Generally speaking, perennial weeds root deep, and dormancy period of seeds or tubers which rest, is not consistent. Moreover, they grow and decay very slowly. These characteristics do not allow herbicides to bring about a satisfactory result; consequently, the integral control through proper combination of herbicides becomes necessary. Presently emphasis is put on the development and utilization of mixed compounds which are capable of controling both annual and perennial weeds simultaneously.

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By citing an example of PCP applied in the paddy field, problems were discussed in relation to methodology applicable to the research on the transition of microflorae in the environment. The further problem seems to be how to generalize the findings of the studies made from both micro and macroscopic viewpoints into a universal law.

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Recent advances of instrumental and technical aspects of GC/MS, involving mass fragmentography, chemical ionization, field desorption and high resolution mass spectrometry are described. A number of examples of applications, especially analysis of pesticides and environmental toxic compounds, are presented with the use of various GC/MS instrumental techniques. Special attention is payed on the quantitative analysis of samples in the range of low nanogram or picogram and the techniques of mass chromatography.

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