In preparation for the potential incursion and spread of citrus leprosis in Florida

Abstract: Citrus leprosis (CiLV) is considered one of the most destructive diseases of citrus, causing blemishing, fruit drop and die-back that can kill the tree if not controlled. The disease is spreading north from South America and has been reported in Mexico. The disease is caused by five distinct viruses (and possible more) that are vectored by Brevipalpus mites. Brevipalpus yothersi (syn. phoenicis) is associated with the most damaging virus CiLV-C in Brazil, Colombia, and Mexico. Both CiLV and B. yothersi have a broad host range. All regions recently infected with CiLV had non-virulent B. yothersi mites prior to disease emerging, and Florida has non-virulent B. yothersi populations. In preparation for a potential incursion of CiLV in Florida, CiLV infected areas in Colombia and Mexico were surveyed to determine the incidence of viruliferous mites on citrus and non-citrus hosts. Surveys were also conducted in south Florida to determine the host plant range of Brevipalpus spp. and their prevalence and distribution in citrus orchards. In Colombia, viruliferous mites were found on four plants including citrus. In Mexico, viruliferous mites were found only on citrus plants. In Florida, B. yothersi and an unidentified Brevipalpus sp. were found on 20 plant species: Five plants had both species, three plants had only the unidentified Brevipalpus sp, and 12 species had only B. yothersi. We report 7 new host records for B. yothersi. Three species of predatory mites were found associated with Brevipalpus spp. in Florida. Our study suggests that B. yothersi has a broad host range in South Florida and is a common resident of citrus groves which could increase the spread of CiLV if the disease reaches the U.S.A. Mitigation tactics and the potential use of existing natural enemies to control Brevipalpus spp. are discussed.