Occurrence and distribution of nematodes in Idaho crops

Surveys were conducted in Idaho, USA during the 2000-2006 cropping seasons to study the occurrence, population density, host association and distribution of plant-parasitic nematodes associated with major crops, grasses and weeds. Eighty-four species and 43 genera of plant-parasitic nematodes were recorded in soil samples from 29 crops in 20 counties in Idaho. Among them, 36 species are new records in this region. The highest number of species belonged to the genus Pratylenchus; P. neglectus was the predominant species among all species of the identified genera. Among the endoparasitic nematodes, the highest percentage of occurrence was Pratylenchus (29.7) followed by Meloidogyne (4.4) and Heterodera (3.4). Among the ectoparasitic nematodes, Helicotylenchus was predominant (8.3) followed by Mesocriconema (5.0) and Tylenchorhynchus (4.8).