The value of vasiform orifice morphology in the taxonomy and phylogeny of whiteflies (Hemiptera: Aleyrodidae)
Author of the article:LIU Jia-Lei** BAI Run-E*** FENG Xiao-Qing LI Jia-Guo YAN Feng-Ming
Author's Workplace：College of Plant Protection, Henan Agricultural University, Zhengzhou 450046, China
Key Words：Aleyrodidae; vasiform orifice; morphological characteristics; taxonomic identification; phylogeny
Abstract：[Aim] To elucidate the taxonomic and phylogenetic value of vasiform orifice morphology in the Aleyrodidae. [Methods] A total of 36 species representing 22 genera and 2 subfamilies, collected from various regions across China, were examined. The morphology and ultrastructure of the vasiform orifice were documented using digital super-depth-of-field microscopy and scanning electron microscopy (SEM). Concurrently, the sequences of 13 protein-coding genes and 2 ribosomal RNA genes from the mitochondrial genome were analyzed to systematically explore the morphological diversity of the vasiform orifice and the consistency of this with phylogenetic relationships. [Results] Although its core morphological features remain highly conserved within genera and species, significant morphological differentiation of the vasiform orifice was apparent at the subfamily, tribal, and generic levels. The structure of the vasiform orifice is homologous and stable in 1st to 4th instar nymphs, rendering it a reliable characteristic for the accurate identification of immature whiteflies. Furthermore, clustering results based on vasiform orifice morphology are largely congruent with the topological structure of the molecular phylogenetic tree constructed using mitochondrial genomic data, indicating that this character carries a robust and stable phylogenetic signal and qualifies as a typical phylogenetically conservative trait. [Conclusion] The vasiform orifice is a key, diagnostic, morphological character for species identification and phylogenetic reconstruction in the Aleyrodidae. Our findings provide novel perspectives and technical approaches for taxonomic revision, accurate identification of different instars, and further investigation into the adaptive evolutionary mechanisms of morphological traits, in whiteflies.