Brevipalpus yothersi Baker (1949) (Acari: Tenuipalpidae) is one of the most mite species known to cause indirect damages in citrus. The importance of this mite is related to the ability to transmit the virus Citrus leprosis virus, which causes the disease known as citrus leprosis. Since 2004, after the reported Huanglongbing (HLB) disease in Brazil, the frequency of insecticides spraying and the incidence of pest mites increased considerably. The population increase of phytophagous mites can be associated to low susceptibility of mites to insecticides, increased dispersion and/or repellency, changes in feeding behavior and oviposition, hormesis effect and reduction in the efficiency of acaricides due to tank mixtures. The reduction of the efficiency of the pesticides in a mixture may occur due to the incompatibility or antagonism between the products due to changes in the physicochemical characteristics of the products or due to biological changes in the target organisms after exposure to the mixture. In previous studies, it was verified that the efficiency of the spirodiclofen acaricide on the B. yothersi mite is reduced when insecticides are added to the spray solution. However, this antagonism was not a result of changes in the physicochemical characteristics. The other possible reason for antagonism between pesticides in the mixture, which has not yet been studied, is the change in the activity of detoxifying enzymes. Thus, the aims of this research project are to characterize the activity of detoxification enzymes induced in B. yothersi mites exposed to isolated and mixed products, quantify the duration of changes in the activities of evaluated enzymes and determine detoxification genes involved in these organisms. We will determine enzymatic activity in mites previously exposed to insecticides and after application of acaricide. The expression of detoxifying genes will be compared among specimens of B. yothersi exposed to insecticides, acaricide, and insecticide in mixture and mites that will not be exposed to pesticides.
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