Morphotaxonomic Assessment of the <i>pratensis</i> Species Complex with Ontogenetic Development and Redescription of <i>Oligonychus pratensis</i> (Banks) (Acari: Prostigmata: Tetranychidae)

Abstract

The Banks grass mite/New World date mite, Oligonychus pratensis (Banks) (Acari: Prostigmata: Tetranychidae), is a globally distributed and economically significant agricultural pest. The present study comprehensively addresses the morphotaxonomic identification of globally reported populations of O. pratensis, to resolve ambiguities within the pratensis complex. Detailed morphological characterizations of all mobile stages (larva, protonymph, deutonymph, male, and female) of the Californian population of O. pratensis were provided, with key diagnostic traits utilized in this taxonomic assessment. The taxonomic notes are provided for worldwide populations of O. pratensis reported from six biogeographic realms. The taxonomic identity of the claimed populations of O. pratensis from South Africa (Afrotropical realm), El Salvador (Neotropical realm), China, Pakistan (Oriental realm), and Saudi Arabia (Palearctic realm) were found to either be “doubtful” or exhibit notable differences compared to the Californian population. Notably, the purported Chinese population of O. pratensis was identified as a cryptic species, likely a novel taxon within the gossypii species subgroup. Furthermore, the study confirmed the absence of O. pratensis in Saudi Arabia. Additionally, ontogenetic changes across developmental stages are documented. The findings of this study may contribute to a clearer understanding of the true distribution and global occurrence of O. pratensis, providing robust diagnostic characteristics to support future research.

Keywords

• banks grass mite
• intraspecific variations
• morphology
• new world date mite
• species complex
• species identification