徳島産セスジユスリカ, Chironomus yoshimatsui Martin et Sublette に対する Altosid[○!R] 10F の効果

抄録

The biological activity of methoprene (Isopropyl (2E, 4E)-11-methoxy-3,7,11-trimethyl-2,4-dode-cadienoate) and its slow-release formulation, Altosid[○!R] 10F which contains 10% methoprene, were evaluated against the chironomid midge, Chironomus yoshimatsui Martin et Sublette in both the laboratory and the field. The biological effects of Altosid[○!R] 10F on C. yoshimatsui were similar to those on mosquitoes, resulting in pupal death, failure of emergence and abnormal adults. However, it was a unique phenomenon that pupation was inhibited at higher concentrations in chironomids as compared with mosquitoes. The IC_<50> values of methoprene and Altosid[○!R] 10F to the last instar larvae of C. yoshimatsui were 0.00065ppm and 0.0025ppm, respectively. As C. yoshimatsui larvae inhabit flowing water in drains, a test with short exposure to Altosid[○!R] 10F was undertaken. The IC_<50> value under 2hr exposure to Altosid[○!R] 10F was 0.0044ppm. The field test was conducted during autumn, 1980,against natural populations of C. yoshimatsui and Chironomus sp. in a Tokushima City drain. The concentration of Altosid[○!R] 10F was 0.59ppm of active ingredient/flowing water volume in the drain during treatment time. Then, after Altosid[○!R] 10F was diluted 200-fold with water, the solution was poured into the upper course of the drain for 15min. It was effective for a long period ; neither C. yoshimatsui nor Chironomus sp. emerged for more than 30 days.