Observations on the population dynamics of Longidorus belloi in cereal dields of the Central Region (Spain)

Abstract

The population dynamics of Longidorus belloi was followed between November 1984 and June 1986 in wheat crops of the central region of Spain. Soil samples taken at monthly intervals indicated once-yearly reproduction in the summer, with a maximum in July. First stage juveniles were recovered from all samples and reached their peak in winter (about 50% of the total population). The uther juvenile stages (J2' L, J4) constituted 10-15% of the population and showed low variations except the 4th stage which peaked in summer. Adults reached their maximum (30%) in summer, coincident with the appearance of gravid females, but they decreased in autumn, reaching the lowest level in winter. Analysis of L. belloi fluctuations indicated a marked seasonal variation of the adult population, this fluctuation reflecting the influences of soil temperature and growth stage of the host.