Morphological and genetic variation in Mexican wild populations of tamarixia radiata (Hymenoptera: Eulophidae)

Abstract

We analyzed the morphological and genetic variation of the Asian citrus psyllid nymphal ectoparasitoid Tamarixia radiata (Waterston) (Hymenoptera: Eulophidae) in 2 regions of Mexico, in the northeast (represented by the states of Nuevo León and Tamaulipas) and the west (represented by the states of Colima and Michoacán). We found that the morphological variation of the specimens lay mainly in body color traits. The morphometric study indicated that in comparison with females, males presented heterogeneity, and it was concentrated in the state of Colima. Despite the morphological variation found in the species, it was not exclusively associated with any of the geographical regions. Molecular analysis revealed the presence of 2 haplotypes (H1 and H2), which were the same found in previous research among strains introduced to Florida. Haplotype H2 was found in both studied regions and more frequently than haplotype H1, which was collected only in the northeast (Tamaulipas state), suggesting possible points of gene flow between Mexico and the USA. Our results have implications for the extensive use of T. radiata in biological control programs of the Asian citrus psyllid.