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Toxicological and biochemical response to azinphos‐methyl in Cydia pomonella L. (Lepidoptera: Tortricidae) among orchards from the Argentinian Patagonia
Author(s) -
Soleño Jimena,
Anguiano Liliana,
de D'Angelo Ana Pechen,
Cichón Liliana,
Fernández Darío,
Montagna Cristina
Publication year - 2008
Publication title -
pest management science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.296
H-Index - 125
eISSN - 1526-4998
pISSN - 1526-498X
DOI - 10.1002/ps.1582
Subject(s) - codling moth , tortricidae , orchard , biology , lepidoptera genitalia , population , larva , horticulture , fruit tree , pest analysis , toxicology , malus , botany , medicine , environmental health
BACKGROUND: Azinphos‐methyl is the main insecticide used to control codling moth on apple and pears in Northern Patagonia. The aim of this study was to evaluate the toxicological and biochemical response of diapausing larvae of codling moth in orchards subjected to different insecticide selection pressure. RESULTS: Dose–mortality assays with azinphos‐methyl in diapausing larvae of Cydia pomonella L. showed significant differences between the LD 95 from a population collected in one untreated orchard (2.52 µg moth −1 ) compared with that in a laboratory‐susceptible population (0.33 µg moth −1 ). Toxicity to azinphos‐methyl in field populations of diapausing larvae collected during 2003–2005 was evaluated by topical application of a discriminating dose (2.5 µg moth −1 ) that was obtained from larvae collected in the untreated orchard (field reference strain). Significantly lower mortality (37.71–84.21%) was observed in three out of eight field populations compared with that in the field reference strain. Most of the field populations showed higher esterase activity than that determined in both the laboratory susceptible and the field reference strains. Moreover, there was a high association between esterase activity and mortality ( R 2 = 0.64) among the field populations. On the other hand, a poor correlation was observed between glutathione S ‐transferase activity and mortality ( R 2 = 0.33) among larvae collected from different orchards. CONCLUSIONS: All the field populations evaluated exhibited some degree of azinphos‐methyl tolerance in relation to the laboratory susceptible strain. Biochemical results demonstrated that esterases are at least one of the principal mechanisms involved in tolerance to this insecticide. Copyright © 2008 Society of Chemical Industry