Biogeographical analysis within the family Phytoseiidae Berlese (Acari: Mesostigmata): an example from the large sub-genus Typhlodromus (Anthoseius) De Leon

Despite their great interest for pest management, the biogeography of the Phytoseiidae is still poorly known. This study focuses on the spatial distribution of one of the largest taxa within the family: the sub-genus Typhlodromus (Anthoseius) currently comprising 322 species. It also provides a description of five discrete morphological characters used to discriminate between species and easily observed. This survey is the first analysis of the combined distribution of both species and associated morphological characters within the family Phytoseiidae. It reveals the great utility of taxonomic data compilation and associated databases for aspects beyong alpha-taxonomy. The highest number of species of Typhlodromus (Anthoseius) was reported from the East Palearctic region and the lowest from the Neotropical province. This was quite surprising as the highest species diversity of Phytoseiidae is reported from this latter region. Several hypotheses are discussed to explain this observation. In provinces showing the highest number of Typhlodromus (Anthoseius) species, we usually also observed the most diverse morphological forms for the five characters considered. High endemism levels were observed in all the provinces considered, even those where only few species were reported (especially the Neotropical province). Possible synonymies are thus discussed, as species could have been described more than once in different biogeographic provinces. Furthermore, some hypotheses are discussed to explain the high species and morphological diversity of the sub-genus Typhlodromus (Anthoseius) in theWest and East Palaearctic regions. Further phylogenetic analyses are required to test these different hypotheses.