Natural Populations of Entomopathogenic Nematodes (Rhabditida: Heterorhabditidae, Steinernematidae) from the Hawaiian Islands

Soils from 351 sites representing ecologically diverse habitats from six Hawaiian Islands (sea level to 4,200 m) were assessed for entomopathogenic nematodes using the Galleria baiting technique. Twenty-four sites (6.8%)were positive for entomopathogenic nematodes. Twenty-two sites (6.3%) were positive for a Heterorhabditis sp. from the islands of Kauai (6), Oahu (5), Maui (4), Molokai (1), and Hawaii (6), and two sites were positive for a Steinernema sp. from Maui. No entomopathogenic nematodes were recovered from soils on the island of Lanai. Heterorhabditids were highly correlated with ocean beaches within 100 m of seashore (0 m elevation). These positive sites had soils containing sand grains from coral and shells with moderately alkaline pH (8.0) and low organic content (12%). The steinernematid isolates came from inland areas in silty clay and silt loam soils with higher organic content (15–35%).