The Occurrence and Depth Distribution of Xiphinema and Longidorus Species in Southeastern England 1)

Xiphinema diversicaudatum, Longidorus macrosoma and L. profundorum were found to be fairly widespread in southeastern England, but a Xiphinema sp. occurred at only three localities and X. vuittenezi at only one. Distinct patterns of depth distribution were apparent, varying from the decrease in numbers with increasing depth shown by X. diversicaudatum and X. vuittenezi, through a pattern of increase with depth to a maximum at about 50 cm (Xiphinema sp.) or 70 cm (L. macrosoma) followed by a decrease, to the variable pattern shown by L. profundorum, where numbers increase with depth to about 75 cm and sometimes beyond.