Tamarixia radiata (Waterston) (Hymenoptera: Eulophidae) haplotypes from two Mexican citrus regions

Tamarixia radiata (Waterston) (Hymenoptera: Eulophidae) is a nymphal ectoparasitoid of Diaphorina citri Kuwayama (Hemiptera: Liviidae) the vector of Candidatus Liberibacter spp., the putative agent of Huanglongbing, a devastating disease of citrus worldwide. The parasitoid was accidentally introduced to several regions of the Americas, including Mexico, where presently the species is mass-reared and released. In order to contribute to improve the use of wild populations of T. radiata in the Mexican citrus industry, the objective of this study was to characterize genetically populations of the parasitoid in the eastern region (Nuevo Leon and Tamaulipas states) and western region of Mexico (Colima and Michoacan states) where the citrus grow under different ecological conditions. Using a mitochondrial DNA region (cytochrome oxidase subunit 1) we analyzed T. radiata samples collected during 2006-2013 in the eastern and 2010-2011 in the western. We found two haplotypes (H1 and H2) in the eastern region; in this area, H2 was obtained just from Tamaulipas state. In the western, we only found the H1. This haplotype of T. radiata has been collected in most of the Mexican citrus areas infested by D. citri. In contrast, H2 haplotype has been detected only in Tamaulipas and Yucatán state; its limited distribution in both separated areas suggests possible pathways of the parasitoid´s entry to the country. Also, the restricted dissemination could be associated with special conditions for development and reproduction that have averted dispersion or migration to other areas. Our study has implication for the use of T. radiata in Mexico.