Two synonymy cases within the genus Neoseiulella (Acari: Phytoseiidae): is the molecular evidence so evident?
Résumé
Synonymy is considered as a great problem for diversity characterization and further applications, especially for biological control success with regard to the accurate identification of natural enemies. The present study focuses on two synonymy cases of natural enemies, belonging to the family Phytoseiidae, the genus Neoseiulella, specifically five species of this genus: Neoseiulella tiliarum, Neoseiulella formosa, Neoseiulella aceri, Neoseiulella squamiger, and Neoseiulella aceris. Morphological and molecular analyses [12S rRNA, cytochrome b (Cytb) mitochondrial (mt)DNA, internal transcribed spacer DNA] were applied. First, the results obtained support the synonymy of N. tiliarum and N. formosa. Second, because morphological differences (solenostomes occurrence) were observed for the first time between the type material of N. aceris and N. squamiger, the present study does not provide sufficient evidence to synomymize these two species and further analyses are required. Lastly, we assume that N. squamiger and N. aceri are synonyms. However, three groups of specimens, including N. aceri and N. squamiger, were identified by two mitochondrial DNA genes (12S rRNA and Cytb mtDNA). Therefore, the present study highlights the problems encountered when using only mitochondrial genes to diagnose species. The great mtDNA variations observed appear to reflect population differentiation (linked to plant support). This is the first time that such high intraspecific differentiation is be observed within the family Phytoseiidae. Further experiments, such as cross-breeding and microsatellite DNA marker analyses, are planned to characterize gene flow and reproductive isolation levels within this species