Abstracts of Vol. 27 No. 4

Key words: AR, adsorption, atrazine, Kｄ, linuron, multivariate analysis.

Adaptive mechanism and efflux-transport system of Pseudomonas sp. LE2 were investigated to understand how this microorganism survives in lindane-contaminated environments.　Adaptive mechanism was demonstrated by changes in the ratio of total saturated to unsaturated fatty acids in cells grown on glucose with or without lindane.　The ratio of total saturated to unsaturated fatty acids in cells grown with lindane was 0.9, which was comparable to 0.5 in cells grown without lindane.　Lindane significantly affected in vitro the membrane of cells grown without lindane by decreasing membrane transition temperature from about 25 to 22°C at 8 μM.　Less fluidizing effect of lindane on the membrane of cells that had grown with lindane was observed, giving about 18% of polarization percentage ratio, which was significantly lower than about 52% in cells grown without lindane.　When lindane was incubated with Pseudomonas sp. LE2 cell suspensions, it accumulated in cells by simple diffusion mechanism.　A membrane transport inhibitor, sodium azide, increased considerably lindane accumulation in cells, showing significant inhibition of lindane efflux from cells.　These results suggest the view that Pseudomonas sp. LE2 capable of growing in the presence of lindane is able to adapt to the fluidizing action of lindane by incorporating saturated fatty acids into membrane lipids and eliminating lindane from cells by an energy-dependent efflux mechanism.

Key words: insecticide, lindane, Pseudomonas.

New 2-phenylbenzazole derivatives, thirteen benzoxazoles and eight benzothiazoles, were synthesized, and their acaricidal activities measured against the two-spotted spider mite (TSM).　Some compounds with a polyfluorophenyl group were highly effective in killing the eggs (LC５０: ＜50 ppm) with moderate activity (LC５０: 150‐200 ppm) against the adults.　Among them, 2-(3-chloro-2,4,5-trifluorophenyl)-5-methylbenzoxazole was selected as the most promising candidate for an acaricide, and the effects of its concentrate were evaluated.　This formulation achieved a high rate of mortality in the citrus red mite and a kelthane-resistant strain of TSM in addition to a common strain of TSM.

Key words: benzoxazole, benzothiazole, acaricidal activity, two-spotted spider mite, ovicide.

Natural fluctuations in carbon substrate utilizing activity and community-level physiological profiles of microorganisms in low input and conventional rice paddy soils were monitored using Biolog GN plates for almost two years in order to establish criteria for assessing side-effects of pesticides on soil microbial ecosystems.　The activity changed seasonally showing a regular pattern with more activity observed during late summer in both soils.　The level of activity seemed to be directly influenced by soil tempera-ture and/or redox potential.　Soil microbial communities were grouped into three clusters, Aug‐Dec, Jan‐Apr, and May‐Aug, based on the sampling season.　The first cluster was further divided between the two paddy soils.　The same microbial communities were reestablished in the same season for two successive years in both soils.　Low soil temperatures and reduced soil conditions seemed to be influential in the establishment of the second and third clusters, respectively.　Criteria are proposed for assessing the side-effects of pesticides on microbial function and structure in paddy soils.

Key words: paddy soil, Biolog, microbial community structure, carbon substrate utilizing activity, natural fluctuation, risk assessment of pesticide.

Fourteen analogues were synthesized by rationally modifying the 3,5-dimethylbenzoyl moiety of RH-5992, and evaluated for insecticidal activity against the common cutworm (Spodoptera litura).　Although several derivatives showed good insecticidal activity, they were less active than RH-5992.

Key words: 20-hydroxyecdysone, RH-5992, tebufenozide, ecdysone agonist, insecticidal activity, common cutworm.

Key words: neonicotinoid insecticides, dinotefuran, imidacloprid, SADβ2 hybrid receptors, nicotinic acetylcholine receptor, bioisosterism.

Key words: runoff, Gray lowland soil, Ando soil, pesticide residue on the soils.