局所施用による薬剤感受性検定におけるアリモドキゾウムシの麻酔方法とfenitrothionに対する感受性

抄録

The effect of chilling and CO₂ anesthesia on sweetpotato weevils was investigated to optimize the immobilization duration sufficient for topical application of insecticides. Two-minute CO₂ anesthesia treatment with simultaneous chilling for the latter half of the time immobilized the weevils for about 100 seconds. This duration is sufficient to topically apply insecticides to the weevil bodies. This anesthesia method did not adversely affect the survivorship of weevils. Using this anesthesia method, we investigated the susceptibility to fenitrothion (MEP) of wild weevil populations on Kikai Island, where MEP and synthesized sex pheromone had been applied for 3 years and on Amami Oshima Island where no control measures were implemented. The LD₅₀ values were as low (about 4.0–8.0 μg/g) for sweetpotato weevils collected from Kikai Island as for weevils collected from the control, Amami Oshima Island (about 2.5 μg/g). This result suggests that the weevil-controlling measures on Kikai Island are working satisfactorily.