The enantiomers of chiral pesticides are often metabolized at different rates. In agriculture, the preferred chiral form of a pesticide is more effective at lower application rates or more specific toward a targeted pest. Other advantages of chiral pure pesticides include greater environmental safety, reduced cost, greater specificity and extended patent life. Recent progress in optical resolution, asymmetric synthesis and biocatalysis of chiral pesticides has been described. Techniques to separate enantiomers with chiral HPLC and GC columns, electrophoresis and mass spectrometry have been reported. Chiral chase is actively pursuing asymmetric hydrogenation for the manufacture of a pure single-enantiomer pesticide. Enantioselectivity occurs in pesticidal activities toward target organisms as well as non-targeted organisms. There is a need to characterize both enantiomers of chiral pesticides in order to have an accurate understanding of their distribution and fate in the environment. Enantiomeric analysis can be useful in this aim and this is an important consideration in the risk assessment of pesticides. Use of only the target-active enantiomer of pesticides should be encouraged as it will reduce the pollutant load, provided it has no adverse impact on non-target organisms.

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A new insecticide bioassay for assessing the effects of acute insecticide toxicity on lotic insects was developed. It uses first-instar larvae of a net-spinning caddisfly, Cheumatopsyche brevilineata. The test method was suitable for 30 insecticides with a range of action mechanisms. Caddisfly larvae were much more sensitive than daphnids to neonicotinoids. The new bioassay is thus a useful and reliable method for assessing the impact of chemicals such as neonicotinoids, whose risks for lotic insects might be underestimated by the daphnid bioassay.

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To determine sensitivity to fenitrothion (MEP), fenobucarb (BPMC) and imidacloprid (IMI) in each larval instar of Cheumatopsyche brevilineata, we carried out 48-hr acute toxicity tests using strains M and K originating from an urban river and an irrigation canal, respectively. First instar was the most sensitive stage to all three insecticides whereas fifth instar was the most insensitive in both strains. Larvae of strain K were significantly more insensitive to MEP through larval growth and to BPMC in second or later instars than larvae of strain M; however, sensitivity to IMI did not differ significantly between strains.

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The aerobic aquatic soil metabolism of esfenvalerate [(2S,αS)-α-cyano-3-phenoxybenzyl 2-(4-chlorophenyl)-3-methylbutyrate] was examined in two Japanese pond water-sediment systems in relation to the effects of illumination and formulation on degradation profiles. Esfenvalerate was rapidly partitioned from the water phase to the bottom sediments with dissipation half-lives of less than 1 day and either the application of formulation or illumination slightly accelerated the partition. The main degradate of esfenvalerate was 3-phenoxybenzoic acid via ester cleavage both under dark and light conditions. The epimerization at the α-cyanobenzyl carbon significantly proceeded to form the corresponding [2S,αR] isomer in both water and sediment. The possible degradate via photo-induced decarboxylation was scarcely detected in the water phase of the illuminated water-sediment systems.

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Flubendiamide is the first benzenedicarboxamide compound developed as an insecticide with potent activity against lepidopterous pests. It has already been clarified that insecticidal activity of the compound is mediated through modulation of the ryanodine-sensitive Ca²⁺ release channel, (ryanodine receptors; RyRs). The present study showed close correlation between insecticidal activities and stimulating effects on the Ca²⁺ pump, a functional co-operative element with RyR activity, and implied the involvement of Ca²⁺ pump stimulation in insecticidal activity. This result suggested that Ca²⁺ pump activity could be a convenient indicator for determining RyR activity.

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The concentrations of Spintor 480 SC^® tested in the laboratory experiments were 0.005, 0.01 and 0.015% instead the 0.05, 0.1 and 0.15% that appeared in the manuscript. Accordingly, in the field experiment we tested 0.01% of Spintor 480 instead 0.1%.

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The present study monitored spray drift, deposition and residues on branches and leaves of pine trees over time after Sumipine MC^® was applied by a radio-controlled helicopter over pine trees at Katagami-shi Tenno, Hamayama-chiku, Akita prefecture in 2006. As bio-monitoring of the spray drift, the mortality of the housefly in various locations was also observed. Fenitrothion in the atmosphere was trapped at several locations within and around the sprayed area using a Sep-Pak PS-Air cartridge, which was placed horizontally at heights of 15, 8 and 1.5 m above the ground. All atmospheric fenitrothion detected was below the permissible limit of 10 μg/m³, except within the sprayed area. These results imply that the Sumipine MC^® spray poses little health risk to neighboring inhabitants.

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