Silva G A R, Lapenta A S
Departamento de Biologia Celular e Genética, Universidade Estadual de Maringá, Avenida Colombo 5790, Maringá-Pr, Brazil.
Bull Entomol Res. 2011 Apr;101(2):177-85. doi: 10.1017/S0007485310000325. Epub 2010 Nov 1.
Oryzaephilus mercator and O. surinamensis are stored grains and processed food pests, the latter being responsible for major economical losses. Polyacrylamide gel electrophoresis was used to analyse esterase patterns during insect development. Seven esterases, three cholinesterases, two carboxylesterases and two acetylesterases, were identified in O. mercator, one of which was proper to adults. Five esterases, of which four were cholinesterases, occurred in O. surinamensis. Strains of O. mercator and O. surinamensis were also exposed to malathion and chlorpyrifos-methyl. According to the LC50 estimates, OmLC-M and OmLA strains of O. mercator and OsLB strain of O. surinamensis were the most resistant to both insecticides. However, higher sensitivity to malathion and chlorpyrifos-methyl has also been verified in some of its esterases. Cholinesterases OmEST-1 and OsEST-5 seem to be involved in this resistance. These results suggest that organophosphate tolerance may be related to genetic variability in esterase isoenzymes.
米象和锯谷盗是储粮和加工食品害虫，后者会造成重大经济损失。采用聚丙烯酰胺凝胶电泳分析昆虫发育过程中的酯酶图谱。在米象中鉴定出七种酯酶、三种胆碱酯酶、两种羧酸酯酶和两种乙酰酯酶，其中一种是成虫特有的。锯谷盗中有五种酯酶，其中四种是胆碱酯酶。米象和锯谷盗品系也接触了马拉硫磷和甲基毒死蜱。根据半数致死浓度（LC50）估计，米象的OmLC-M和OmLA品系以及锯谷盗的OsLB品系对这两种杀虫剂最具抗性。然而，在其一些酯酶中也证实了对马拉硫磷和甲基毒死蜱具有更高的敏感性。胆碱酯酶OmEST-1和OsEST-5似乎与这种抗性有关。这些结果表明，有机磷耐受性可能与酯酶同工酶的遗传变异性有关。
