No abstract

Citrus leprosis mite is an important pest to Brazilian citriculture. Due to the potential damage caused by the virus transmitted by this mite, synthetic acaricides are the main management strategy used by citrus growers to reduce the vector population. The current review aims to provide historical data on the use of acaricides to control the citrus leprosis mite and the main factors involved with the efficacy of these products. To get to know the main products that were and have been used to control the leprosis mite, we used scientific papers that studied the toxic effect caused by pesticides on these mites. From 1959 to nowadays, more than 200 papers have been published demonstrating acaricide efficacy on the leprosis mite. Although there are several acaricides registered to control the leprosis mite (abamectin, amitraz, acrinathrin, bifenthrin, fenpropathrin, etoxazole, hexythiazox, flufenoxuron, spirodiclofen, cyflumetofen, chlorfenapyr, fenbutatin oxide, propargite, fenpyroximate, pyridaben, and sulfur), their effectiveness will be determined by factors inherent to the products, application (quality of the spray water, plant coverage by sprayed acaricide, addition of adjuvants, and tank mixture), and biological factors of the pest (biotic potential, short life cycle, reproduction type, initial infestation level, reproduction type, and evolution of mite resistance). The use of synthetic acaricides is a control option that generates short-term results for the citrus grower. However, the association with other control measures will allow more satisfactory results for the pathosystem. Additionally, information on factors that interfere with the effectiveness of acaricides needs to be generated and made available to citrus growers.

Brevipalpus yothersi is an important pest to citrus crop due to its ability to transmit the virus that causes citrus leprosis. The exposure of target and non-target organisms to different pesticides is a reality in field conditions. For successful management, it is essential to determine the effects of citrus commonly used pesticides on leprosis mites to determine how pesticides can interfere with the leprosis mite population. Therefore, this study aimed to evaluate the impact of insecticides, alone or associated with spirodiclofen, on B. yothersi life history traits and demographic parameters under laboratory and greenhouse conditions. Results suggest that cypermethrin and imidacloprid, both alone and in a mixture with spirodiclofen, phosmet in a mix with spirodiclofen and spirodiclofen alone did not interfere significantly in the fecundity and fertility of B. yothersi in laboratory conditions. In the same condition, only phosmet at 15.6, 125.0, and 250.0 mg.L-1 reduced the fecundity of the mites. Brevipalpus yothersi population varied with the insecticide and mixture type in the greenhouse condition. Most insecticides and acaricide, alone or in a mixture, decreased pre-adult development, whereas female adult longevity was similar to control. Spirodiclofen combined with phosmet and imidacloprid decreased female adult longevity. Only spirodiclofen in a mixture with cypermethrin and phosmet alone did not interfere significantly with the intrinsic rate of population increase. The other insecticides and mixtures reduced that parameter. The mean time of one mite generation was decreased when the mites were exposed to all insecticides and acaricide combinations, spirodiclofen and phosmet alone. Therefore, cypermethrin, phosmet, imidacloprid, and spirodiclofen, alone or in a mixture, negatively impacted the development time and demographic parameters of B. yothersi.