Molecular phylogeny and identification of Tuta absoluta (Lepidoptera: Gelechiidae) based on mitochondrial DNA

Abstract

A new pest of tomato, the South American tomato pinworm, Tuta absoluta (Meyrick, 1917) (Lepidoptera: Gelechiidae), was found in Kumamoto Prefecture, Japan in 2021. We examined the genetic variation in the DNA sequences of the mitochondrial cytochrome c oxidase subunit I (mtCOI) gene in 1039 individuals belonging to 39 countries including Japan. In the maximum likelihood phylogenetic tree and haplotype network, 19 haplotypes were detected in the world. Of those haplotypes, only one haplotype (Ta1) was detected from all 39 countries including neighboring countries and Japan. These results and some other information suggest that this species migrated from neighboring countries to Japan. Furthermore, we developed a Multiplex PCR using species-specific primers to discriminate T. absoluta from other gelechiid moth, Phthorimaea operculella (Zeller, 1873) (Lepidoptera: Gelechiidae). We could successfully identify the first instar larvae, fourth instar larvae, pupae, and adults of both species based on the differences in the length of amplicon bands. In addition, we were able to identify adults of both species collected from various prefectures. These results indicated that the Multiplex PCR developed in this study is useful to identify all developmental stages of both species collected in the fields.