Resistance of Brevipalpus phoenicis (Geijskes, 1939) (Acari: Tenuipalpidae) to acaricides that inhibit cellular respiration in citrus groves / Resistência de Brevipalpus phoenicis (Geijskes, 1939) (Acari: Tenuipalpidae) a acaricidas inibidores da respiração celular na cultura dos citros




Acaricides that affect the cellular respiration process, specifically in the energy production (ATP), have been an important component in acaricide resistance management programs. Basically, these acaricides interfere in the oxidative phosphorilation or electron transportation in the mitochondria, by inhibiting or disrupting some specific process. This group of acaricide plays an important role in the control of Brevipalpus phoenicis (Geijskes) in citrus groves in Brazil. However, there are only few studies on the susceptibility and possible crossresistance to the acaricides that are inhibitors of cellular respiration in B. phoenicis . Then, the major objective of this work was to collect data to implement strategies to manage the resistance of B. phoenicis to these acaricides. Studies were conducted to evaluate (a) the variability in the susceptibility among B. phoenicis populations collected from citrus groves to the acaricides cyhexatin, azocyclotin, propargite and sulphur; (b) cross-resistance relationships between propargite and the acaricides azocyclotin, cyhexatin, dinocap, pyridaben and sulphur; and (c) the fitness cost associated with propargite resistance in B. phoenicis under laboratory conditions. A residual-type contact bioassay was used to characterize the susceptibility of B. phoenicis to these acaricides. The monitoring of the susceptibility to these acaricides in different B. phoenicis populations was conducted with diagnostic concentrations based on lethal concentration 95 (LC95) of each acaricide. The cross-resistance between propargite and other acaricides was evaluated by characterizing the concentration-mortality responses of susceptible (S) and propargite-resistant (Propargite-R) strains to cyhexatin, azocyclotin, dinocap, pyridaben and sulphur. The fitness cost associated with B. phoenicis resistance to propargite was evaluated by measuring the biological parameters of S and Propargite-R strains on citrus fruits at 25 ± 1 °C and fotophase of 14 h. Significant differences in the susceptibility of B. phoenicis were detected at diagnostic concentration of cyhexatin (survivorship from 16.3 to 80.5%), azocyclotin (from 3.0 to 15.0%), propargite (from 1.0 a 71.6%) and sulphur (from 9.0 to 82.6%). A low intensity of crossresistance was detected between propargite and the acaricides azocyclotin (1.8-fold), cyhexatin (4.6-fold), dinocap (3.5-fold) and pyridaben (3.5-fold). On the other hand, the intensity of crossresistance to sulphur (>111-fold) was very high. There was no fitness cost associated with B. phoenicis resistance to propargite, based on biological parameters evaluated. Therefore, the use of these acaricides should also be done very carefully in resistance management of B. phoenicis to acaricides.


chemical control leprose phytophagous mites citricultura controle químico acaricidas – resistência Ácaros parasitos de plantas leprosis citrus groves acaricide – resistance

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