Analysis of the geographical distribution of Xiphinema diversicaudatum and X. pachtaicum in relation to the environmental factors in Spain

Abstract

Knowledge of the environmental factors affecting the distribution of soil inhabiting nematodes can indicate the areas in which species can or cannot spread and thus is helpful in establishing control measures for pathogenic species. Most field investigations concerned with pathogenic nematodes are conducted in the crops in which they are causing damage but many of these species also inhabit uncultivated areas and a study of these can be very informative with regard to nematode behaviour. This view gave rise to our studies of the behaviour and distribution of virus vector nematodes of the family Longidoridae in Spain. The Atlas of Longidoridae in Spain (Arias, 1979), which is a contribution to the European Plant Parasitic Survey, was based on 5000 soil samples collected mainly from the cultivated soils at the bottom of valleys (Fig. 1). Xiphinema species were collected more frequently than Longidorus and therefore Xiphinema was chosen for an examination of ecological factors affecting the occurrence and distribution of individual species.