Enhanced esterase activity and azinphosmethyl exposure association in target and non target organism

MONTAGNA, CRISTINA MÓNICA; FERRARI, ANA; SOLEÑO, JIMENA; VENTURINO, ANDRÉS; ANGUIANO, OLGA LILIANA

Porto, Portugal

Congreso; SETAC Europe 17th Annual Meeting; 2007

The organophosphate azinphosmethyl (AzMe) is extensively applied in the Alto Valle (Argentinean Patagonia) to control codling moths (Cydia pomonella) form apples. This area is irrigated by fast-flowing channels providing a favourable habitat for many species including black fly (Simulium spp) and amphipods (Hyalella curvispina). Previously, we have observed differences in toxicity to AzMe between insecticide exposed and non-exposed populations. In this study, we individually assayed esterase activity from all populations. The three populations of organisms from pesticide exposed sites showed significantly higher (p<0.001) esterase activities (umol x min-1 x mg prot-1) than the control ones. Mean enzyme activities were 2.17 +1.71  and 0.81 + 0.35 for Simulium spp; 0.27 + 0.10 and 0.14 + 0.07 for H. curvispina and at last, 0.21 + 0.16 and 0.016 + 0.011 for C. pomonella. Therefore, we conclude that the differences in toxicity to AzMe between insecticide exposed and non-exposed populations of simulids, amphipods and codling moths are least due to enhanced esterase activity.