Mortality response of the greater wax moth, Galleria mellonella (L.), (Fresno, California tests), an insect host substitute for pink bollworm, Pectinophora gossypiella (Saunders), indicated six entomopathogenic nematodes tested varied in their ability to penetrate a 5 cm sand barrier and infect host larvae. The nematodes evaluated, listed in order of host searching efficacy, were (a) Steinernema sp. from the lower Rio Grande Valley, (b) Heterorhabditus bacteriophora, HP 88, (c) H. bacteriophora, Bioenterprise strain, (d) S. carpocapsae, Kapow, (e) All, and (f) UK strains.