Abstract
We present results of the inventory of the spider mites of the Massane Forest Nature Reserve made during several field samplings from 2013 to 2017. Nineteen species have been recorded, which represents more than one third of the known spider mite fauna in France. Among them, three new species were disclosed and are described: Bryobia (Bryobia) alberensis sp. nov. collected on Phyteuma spicatum and Helichrysum stoechas, B. (Periplanobia) polymorpha sp. nov. on Genista pilosa and Tetranychus visigothus sp. nov., on Eryngium campestre, respectively. In addition, three spider mite species, Bryobia (Periplanobia) serifiotica, Eotetranychus aurantii and Eotetranychus fagi are recorded from France for the first time and three plant species are recorded as new host plants for tetranychid mites. The species delineation of B. (P.) polymorpha sp. nov., that presented large variation in dorsal setae length and shape, was investigated using a combination of morphological and molecular data. This approach allowed us to conclude that, despite such variations in a morphological key character, all the specimens observed belong to the same species.