Criconematoidea

Criconematids are one of the major groups of plant-parasitic nematodes and occur from the tropics to the arctic. They include those commonly named as ‘ring nematodes’, ‘sheath nematodes’, ‘pin nematodes’ and ‘the citrus nematode’. While a few species are adapted to a number of agricultural crops, the vast majority are confined to natural habitats with a relatively stable soil structure. As a group, they exhibit a relatively wide host range. Females and most juveniles are obligate root ectoparasites, though some females of Tylenchulidae may become secondarily semi-endoparasitic. The morphology, bionomics and classification of the superfamily Criconematoidea and families Criconematidae, Hemicycliophoridae and Tylenchulidae are discussed with keys to taxa.