XPER This application describes the first web-based polytomous identification key for the genus Paratylenchus. Here we developed a web-assisted method to achieve an easy and accurate morphometric Paratylenchus species characterisation that would greatly improve identification of these small plant-parasitic nematodes for many diagnostic laboratories. We considered here only the Paratylenchus valid species according to the latest monograph of the genus published by Ghaderi et al. (2016), as well as other Paratylenchus species populations based only on integrative taxonomical identification and the posterior species described comprising a total of 140 nominal species [Van den Berg et al., 2014; Subbotin et al., 2020; Singh et al., 2021; Clavero-Camacho et al. 2021a; 2021b]. This is because of the great cryptic diversity detected in the recent studies of pin nematodes [Van den Berg et al., 2014; Subbotin et al., 2020; Singh et al., 2021; Clavero-Camacho et al. 2021a; 2021b], may alter the real morphometric delimitations for each species. For that, we contemplated all the main diagnostic characters, comprising 11 numerical and 13 categorical characters (Table 1). Selection for quantitative character division in subgroups within each diagnostic numerical character was based on K-means clustering method [Jin and Han, 2011] Link Tutorial Team Juan E. Palomares-Rius, Guillermo León-Ropero, Ilenia Clavero-Camacho, Antonio Archidona-Yuste, Carolina Cantalapiedra-Navarrete, y Pablo Castillo
