The infected shoots are stunted, and the branches gradually

die as the disease progresses [2]. With the increase in disease severity, the yield is reduced and fruits quality is degraded. These affected fruit are smaller, lighter and highly acidic [2]. There are no curative procedures, and control of HLB consists of preventing trees from becoming infected and eradicating infected plants. Consequently, accurate and simple detection methods play a central role in reducing the incidence of HLB. The difficulty of correct diagnoses is partly because of the generic nature of HLB symptoms. The disease is sometimes misdiagnosed as nutrient deficiencies or other plant diseases [3]. Three fastidious α-Proteobacteria species of Candidatus Ro 61-8048 Liberibacter, namely Candidatus Liberibacter asiaticus (Las), Candidatus Liberibacter americanus (Lam) and Candidatus Liberibacter africanus (Laf) are associated with HLB [1, 2, 4]. These three bacteria are associated with different forms of the disease and have worldwide distribution. Las has been reported to

be the most widespread, destructive, and economically important, being present in Asia, Brazil and North America [1, 2]. Lam and Laf are found in Brazil and Southern Africa respectively [1, 3, 5]. These pathogens are transmitted by grafting and by the sap-sucking psyllids Diaphorina citri in America and Asia, and Trioza erytreae in South Africa [6]. Diaphorina citri PSI-7977 cost is Belnacasan supplier considered the most serious pest of citrus worldwide, due primarily to its role as vector

of Las[6]. The insect is present in America and Asia, and it spreads rapidly in residential and commercial plantings through natural ways, but also by commercial transport of infected plant material [6, 7]. Worldwide, control of the psyllid Diaphorina citri as a vector is a central milestone in HLB management [6]. Therefore detection of infected insects is critical in preventing the spread of the disease [7]. Currently, the major initial detection procedure for Las is visual inspection based on disease symptoms in trees. Samples that either are suspected to be positive are sent to diagnostic laboratories for secondary analysis. Several methodologies have been developed to detect Las in these samples, including serologic assays, electron microscopy, biological assays, DNA probes, Loop Mediated Isothermal Amplification, PCR and real-time PCR [1, 8–16]. Many of these methods have the drawback of being time-consuming and requiring complex facilities. In addition to some of these approaches, detection of the pathogen in infected plants or vectors remain problematic [3]. In recent years, diagnosis of HLB by real time PCR methodologies has gained popularity due to its sensitivity and reliability [3, 4, 9, 15], however real time PCR requires an expensive thermal cycler with a fluorescence detector, and highly trained personnel to perform assays and analyze data.