Life-Cycle Studies of Some Xiphinema and Longidorus Species in Southeastern England 1)

Systematic sampling of field populations of Xiphinema diversicaudatum, a Xiphinema sp., X. vuittenezi, Longidorus macrosoma and L. profundorum showed that eggs were produced only during a brief period in early summer, but the proportions of each larval and adult stage in the populations showed no comparable annual cycle. Culture studies of X. diversicaudatum and X. vuittenezi, begun with single stages in isolation, showed that several months may elapse between moults, and confirmed that development from egg to adult takes at least two years. It is highly probable that the other three species conform to this pattern. The life span of these species seems commonly to be between 3 and 5 years, and in some individuals may considerably exceed this period.