Neozygites osornensis is a recently described aphid pathogen characterized by morphological criteria and compared with two morphologically close taxa, Neozygites cinarae and Neozygites turbinata. Neozygites species are traditionally classified based on morphological characteristics and molecular data that would confirm these taxa and permit investigation of their phylogenetic relationships are scarce. In this study, we successfully evaluated a genetic variation within partial 18S rDNA sequences among the three Neozygites species and supported the recent erection of N. osornensis as a new species. A phylogenic analysis was also included to support our results.