Bionomics and identification of the genus Rotylenchus (Nematoda: Hoplolaimidae)

Abstract

Plant-parasitic nematodes are an important group of soil borne pathogens causing yield loss to crop plants. The spiral plant-parasitic nematode genus Rotylenchus is a cosmopolitan group of nematodes which is predominantly found in temperate regions of the world. In this genus are included a number of species of significant economic importance in agriculture. They parasitise a wide-range of hosts, including vegetables, ornamentals, and fruit and forest trees. We therefore considered it useful to collect in a book all the information available in the current literature. Our views, which are the result of hard and patient work, are offered in this volume. The book comprises seven sections and presents summarised and specialised information on various aspects of the spiral nematodes belonging to the genus Rotylenchus. Sections 1 and 2 describe the importance of Rotylenchus species in agricultural crops, their distribution and numerous aspects of their biology, feeding habits, pathogenicity to vegetables, fruit and forest trees, and ecology. Section 3 presents different management strategies for the most important and pathogenic species of Rotylenchus, including chemical control, crop rotation, and biological control by means of nematophagous fungi, entomopathogenic nematodes, the hyperparasitic bacteria Pasteuria penetrans, and nematicidal plants. Sections 4 and 5 describes the most important morphological characters used in characterising and diagnosing species, as well as a broad discussion on the taxonomy and systematics in Rotylenchus and related genera, including a list of nominal species. These sections also include morphometric and cluster analyses in order to separate groups of species in order to facilitate identification. Section 6 provides a complete description and measurements of all populations characterised for each species, as well as their world distribution. Finally, Section 7 includes comprehensive tabular and dichotomous keys for species identification. Whilst recognising the complexity of creating a system to identificate such a large number of species, we are nevertheless confident that, by using both systems, the reader has the wherewithall to identify the species of Rotylenchus they are dealing with.