Correlated Insecticide Cross-Resistance in Azinphosmethyl Resistant Codling Moth (Lepidoptera: Tortricidae)

Abstract

Resistance to several classes of insecticides was correlated with azinphosmethyl resistance in codling moth, Cydia pomonella (L.), in California. In tests of laboratory and field populations, cross-resistance was positively correlated with azinphosmethyl and two organophosphates (diazinon, phosmet), a carbamate (carbaryl), a chlorinated hydrocarbon (DDT), and two pyrethroids (esfenvalerate and fenpropathrin). Additionally, negatively correlated cross-resistance was identified between azinphosmethyl and two other organophosphates, chlorpyrifos and methyl parathion. Patterns of resistance observed in laboratory colonies were confirmed with field bioassays. In bioassays of field populations, azinphosmethyl resistance was observed to increase from 1991 to 1993, although levels of resistance remained < 13-fold. Because orchards with azinphosmethyl resistance have had difficulties with suppression of codling moth, and cross-resistance was found for all tested classes of insecticides, strategies for managing resistance will need to be developed so as to protect current and future control tactics. The two insecticides with negatively correlated cross-resistance are discussed as potential tools for resistance management.

Evaluation of mechanisms of azinphos‐methyl resistance in the codling moth Cydia pomonella (L.)

“…In this context, it is noteworthy that no differences in mortality rates between azinphos-methyl-resistant and susceptible neonate codling moth larvae were observed when treated with methyl-parathion and chlorpyrifos (Reuveny and Cohen, unpublished data). However, negatively correlated cross-resistance between azinphos-methyl and chlorpyrifos and methyl-parathion was detected in the codling moth in California (Dunley and Welter, 2000).…”

Insecticide resistance may enhance the response to a host-plant volatile kairomone for the codling moth, Cydia pomonella (L.)

“…The occurrence of negative cross-resistance between two insecticides is likely to result in a selection against resistance to one insecticide if the other one is used (Tabashnik 1990). A negative crossresistance between azinphosmethyl and two other organophosphates, chlorpyriphos and methyl parathion, was demonstrated in North American populations of C. pomonella (Dunley and Welter 2000), allowing the development of resistance management strategies based on alternation of these insecticides between seasons. Similarly, a decrease in resistance frequency may result from higher fitness of susceptible individuals expected under direct control measures involving the pear ester, i.e., attract-and-kill technology including the pear ester as an attractant or mating disruption implemented by associating the pear ester to the sexual pheromone of C. pomonella (Light and Knight 2006).…”

Acetylcholinesterase mutation in an insecticide-resistant population of the codling moth Cydia pomonella (L.)

“…In the codling moth, Cydia pomonella L., cross-resistances to different classes of insecticides have been related to enhanced detoxification (Sauphanor et al, 1997;Bouvier et al, 2002), whereas a kdr mutation through leucine to phenylalanine replacement at position 1014 of the voltagedependent sodium channel gene has been identified in pyrethroid resistant populations (Brun-Barale et al, 2005). Organophosphorous (OP) insecticides are the most intensively used against C. pomonella worldwide and resistances to these compounds have frequently been recorded in this species (Welter et al, 1991;Bush et al, 1993;Knight et al, 1994;Sauphanor et al, 1998;Dunley and Welter, 2000;Reuveny and Cohen, 2004). OPs irreversibly inhibit acetylcholinesterase (AChE, EC 3.1.1.7) which is a key enzyme catalysing the hydrolysis of the neurotransmitter acetylcholine in the nervous system, thereby ending transmission of nerve impulses at cholinergic synapses.…”