Acknowledgements
I would like to thank the University of Jaén for the financial and technical support received through the research programmes ‘PAIJUA 2017/2018 and 2019/2020: EI_RNM02_2017 and 2019’ for my scientific work throughout the last four years, when this book was conceived and written. My gratitude also to Marı́a del Mar López-Castro, staff member of the Library of the Universisty of Jaén, who assisted me in accessing old and/or rare nematological publications. Most line illustrations have been taken from many authors and contributions, all of them cited, referenced in detail, and deeply appreciated. Finally, but no less important, the advice received from David Hunt and Roland Perry, in particular their editoral comments and suggestions and, very especially, their revision of the English text, have been of inestimable value and deserving of my enormous gratitude.