INFECTIVITY OF ENTOMOGENOUS NEMATODES (STEINERNEMATIDAE AND HETERORHABDITIDAE) TO PEDICULUS-HUMANUS-CAPITIS DE-GEER (ANOPLURA, PEDICULIDAE)

The susceptibility of human head lice, Pediculus humanus capitis, to t hree species of Argentinean entomogenous nematodes, Steinernema rara, S. feltiae, and Heterorhabditis bacteriophora (Oliva and Rio Negro str ains), was studied. All species and strains, except S. feltiae, killed adult and nymph head lice. None of the species killed the eggs. S. ra ra and the Rio Negro strain of H. bacteriophora killed both adults and nymphs; on the contrary H. bacteriophora Oliva was more aggressive to adults. Apparently, penetration into the lice body takes place throug h the spiracles, which means that the body size of the infective juven iles is a limiting factor. This is the first report of parasitism in h ead lice by entomogenous nematodes.