Enhanced esterase activity and azinphosmethyl exposure association in target and non-target organisms

ANGUIANO, OLGA LILIANA; FERRARI, ANA; SOLEÑO, JIMENA; MATÍNEZ, MARÍA CELINA; VENTURINO, ANDRÉS; PECHEN DE D'ANGELO, ANA MARÍA; MONTAGNA, CRISTINA MÓNICA

ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY

Año: 2008 vol. 27 p. 2117 - 2123

0730-7268

Abstract – The organophosphorus azinphosmethyl (AzMe) is extensively applied in the Northern Patagonia to manage codling moths (Cydia pomonella). This area is irrigated by fast-flowing channels providing a favorable habitat for many species including amphipods (Hyalella curvispina) and a field-mixed population of black flies (Simulium bonaerense, Simulium wolffhuegeli and Simulium nigristrigatum). In the present study, AzMe susceptibility and carboxylesterase (CarbE) activity from both insecticide-exposed and non-exposed field populations were studied. The lethal dose 50 (LD50) determined in codling moths from an insecticide-treated orchard was significantly higher (3.48 µg/insect) than that observed in those from an untreated orchard (0.69 µg/insect). Similarly, the lethal concentration 50 (LC50) determined in black flies collected from the treated area (0.021 mg/L) was significantly higher than that recorded in those from the untreated site (0.011 mg/L). For amphipods, both a sub-population susceptible to AzMe (LC50 = 1.83 µg/L) and a resistant one (LC50 = 390 µg/L) were found in the treated area. Both sub-populations were more resistant to AzMe than the one from the untreated site (LC50 = 0.43 mg/L). Significant differences (p < 0.001) in CarbE activities were observed between populations from pesticide-treated and non-treated areas. Mean activities from treated and untreated sites were 0.21 ± 0.16 µmol/min/mg protein and 0.016 ± 0.008 µmol/min/mg protein for codling moths; 2.17 ± 1.71 µmol/min/mg protein and 0.81 ± 0.35 µmol/min/mg protein for black flies and 0.27 ± 0.10 µmol/min/mg protein and 0.14 ± 0.07 µmol/min/mg protein for amphipods,