Vairimorpha aylae sp. nov. (Microsporida, Nosematidae), a New Microsporidian Pathogen of the Box Tree Moth, Cydalima perspectalis (Walker, 1859) (Lepidoptera, Crambidae).

BACKGROUND: The box-tree moth, Cydalima perspectalis (Lepidoptera, Crambidae) is the most important pest of the box-trees, Buxus spp. If its population is not suppressed, the box tree habitats will probably disappear completely. Alternative control strategies that can be used in the control of the pest are given in the literature. Entomopathogens could play a role as natural suppressors in C. perspectalis populations. METHODS: Larval specimens were collected from C. perspectalis populations in Bilecik, Türkiye. Infected larvae of C. perspectalis were dissected individually under a stereo microscope and examined for pathogens by light and TEM microscopies. Results were confirmed by a molecular phylogenetic analysis. RESULTS: Microsporidian pathogen caused general infestation in C. perpectalis. Spores stained with Giemsa's stain measured 4.22 ± 0.24 μm in length and 2.48 ± 0.24 μm in width. The mature spore wall was considerably thick and measures 145 nm ± 46.04 nm and consisted of a clear thick endospore (119.4 ± 38.12 nm) and an electron-dense, uniform, thin exospore (31.67 ± 5.16 nm). Spores had isofilar polar filament with 15-17 coils measured 89.6 ± 9.64 nm in diameter. The phylogenetic tree constructed based on the SSU rDNA sequence analysis supports the morphological and ultrastructural characteristics. CONCLUSION: To date, no protists or microsporidian pathogens have been isolated from natural populations of C. perspectalis. In this study, we report a microsporidian pathogen infecting C. perspectalis and present a thorough morphological, ultrastructural and molecular identification of a new microsporidium by describing it as a new species of the genus Vairimorpha and named Vairimorpha aylae sp. n. for the first time.