谷蠹、米象和锈赤扁谷盗的PH_3抗性品系对杀螟松和氯化苦的交互抗性研究

用 4个谷蠹、5个米象和 4个锈赤扁谷盗磷化氢抗性品系进行了磷化氢抗性品系害虫对杀螟松和氯化苦的交互抗性试验。对杀螟松的抗性试验用FAO滤纸药膜法进行 ,对氯化苦的抗性试验参照FAO磷化氢抗性测定法 ,在干燥器内熏蒸处理。试验结果表明米象和锈赤扁谷盗的磷化氢抗性品系对氯化苦和杀螟松没有交互抗性。但两个谷蠹的磷化氢抗性品系对杀螟松表现出一定抗性 ,其抗性系数分别为 2 .94和 5.2 4。由于并非所有的磷化氢抗性品系都对杀螟松具有抗性 ,所以我们估计这种抗性是这些害虫以前接触过此种杀虫剂或类似的杀虫剂所引起的。所有的谷蠹品系对氯化苦都没有抗性。上述结果表明 ,为控制害虫对磷化氢抗性发展而采用轮换使用药剂策略时 ,氯化苦和杀螟松都是合适的轮换对象。

STUDIES ON CROSS RESISTANCE OF PHOSPHINE RESISTANT STRAINS IN STORED GRAIN TO FENITROTHION AND TO CHLOROPICRIN

Four strains of Rhyzopertha dominica (F.)(Coleoptera:Bostrichidae), 5 strains of Sitophilus oryzae (L.)(Coleoptera:Curculionidae) and 4 strains of Cryptolestes ferrugineus (Stepens)(Coleoptera:Cucujidae) resistant to phosphine were tested for corss resistance to fenitrothion and to chloropicrin. Fenitrothion resistance was determined using the impregnated paper assays (FAO Method No.15), and chloropicrin resistance was tested by fumigation in desiccators. The results sowed that phosphine resistant strains of S.oryzae and C.ferrugineus had no cross resistance to chloropicrin or fenitrothion.However,two phosphine resistant strains of R.dominica showed some resistance to fenitrothion with resistance factors of 2.94 and 5.24.Not all phosphine resistant strains showed resistance to fenitrothion,therefore we concluded that this resistance was due to previous exposure of this insects to other insecticides.There was no resistance to chloropicrin in any strains of R.dominica. The results indicate that both fenitrotion and chloropicrin would be suitable alternatives in a rotation strategy to manage the development of PH 3 resistance in these insect pests.