P A

Steinernematids and heterorhabditids are widespread soil nematodes. The dependence of their distribution on habitat type, soil texture, soil pH, and altitude has been studied in some detail, while much less is known about how their occurrence depends on the abundance and habitat preference of their insect hosts. Here we surveyed the entomopathogenic nematode fauna of the Czech Republic and evaluated the impact of ecosystem type, habitat, soil, season, altitude, and insect host species on their prevalence. We also examined the eVect of temperature on their isolation rates in the laboratory. Nine species of the genus Steinernema (S. kraussei