INTERACTIONS BETWEEN NEMATODES AND EARTHWORMS - ENHANCED DISPERSAL OFSTEINERNEMA-CARPOCAPSAE

Dispersal of the nematode Steinernema carpocapsae (All strain), applie d on the top or the bottom of soil columns, was tested in the presence or absence of two earthworm species, Lumbricus terrestris or Aporrect odea trapezoides. Nematode dispersal was estimated after a 2-week peri od with a bioassay against the greater wax moth, Galleria mellonella. Vertical dispersal of nematodes was increased in the presence of earth worms. When nematodes were placed on the surface of soil columns, sign ificantly more nematodes dispersed to the lower half of the columns wh en either earthworm species was present than when earthworms were not present. When nematodes were placed on the bottom of soil columns, sig nificantly more nematodes dispersed to the upper half of the columns w hen L. terrestris was present than when A. trapezoides was present or in the absence of earthworms. Because nematodes were found on the exte rior and in the interior of earthworms, nematode dispersal may be enha nced by direct contact with the earthworms.