Abstract Rhyzopertha dominica is an important insect pest of stored grains in Taiwan. During the period 1979-1994, phoxim has been continuously applied to store house for pest control. Results revealed that the Kuanyin strain was most resistant and that the Hukou strain was most susceptible to phoxim. Samples of R. domminica collected from various areas have developed a 5-68-fold level of resistance compared with the Hukou strain. Phoxim-resistane strain obtained by consecutive selection pressure of phoxim of the Kuanyin strain for five generations showed cross resistance to chlorpyrifos and malathion but no significant cross resistance to carbamates and pyrethorids. Temperature is a maajor factor that significantly influences the performance of insectivides. Deltamethrin was more effective at 20℃ than at 30℃ on a phoxim-resistant strain of R. dominica. Bendiocarb was more toxic to a phoxim-resistant strain at 30℃ than 20℃. Therefore, effectiveness of insecticides against stored-product insects may vary with seasonal fluctuation. Bendiocarb and carrbaryl are suggested to be applied to control stored-product insects in the summer season, and deltamethrin the winter. S, S, S, -tributyl phosphorotrithioate (TBPT), an esterases inhibitor, slightly synergized phoxim (2.79-flod) to the phoxim-r-esistant strain. It may be considered that esterases play an important role in phoxim detoxification.
摘要 穀蠹 (Rhyzopertha dominica) 為本省最重要積榖害蟲，在連續十五年使用巴賽松 (phoxim) 防治積榖害蟲後，部份穀蠹品系已對巴賽松產生明顯抗性，其中觀音品系抗性最強，湖口品系最敏感。各品系對巴賽松之LC50與湖口品系相比，所得之相對抗性倍數比在5-68倍之間。再以巴賽松持續篩選觀音品系五代後之巴賽松高抗性品系，對有機磷藥劑陶斯松及馬拉松有明顯交互抗性，而對氨基甲酸鹽及除蟲菊類藥劑的毒效影響不大。溫度對藥劑之毒效影響極為明顯，在20℃時，以第滅寧對巴賽松高抗性品系的毒效最好。在30℃則以免敵克最佳，第滅寧與加保利次之。因此建議冬季使用第滅寧，夏季則使用敵克或加保利。添加水解酵毒抑制劑 TBPT於巴賽松中，對巴賽松高抗性品系之毒效呈現些微協力作用 (2.79倍)，因此推測水解酵素之解毒作用可能在榖蠹對巴賽松抗藥性中參與部份角色。
| Key words: Rhyzopertha dominica, phoxim, cross resistance, temperature, esterases. | | 關鍵詞: 穀蠹、巴賽松、交互抗性、溫度、水解酵素。 |
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