Hashmi, G., Department of Entomology, Cook College, New Jersey Experimental Station, New Brunswick, NJ 08903, United States
Glazer, I., Department of Entomology, Cook College, New Jersey Experimental Station, New Brunswick, NJ 08903, United States
Gaugler, R., Department of Entomology, Cook College, New Jersey Experimental Station, New Brunswick, NJ 08903, United States

The two entomopathogenic nematode genera Heterorhabditis and Steinernema were examined for genetic relatedness by random amplified polymorphic DNA (RAPD) markers. Species of these genera have great potential for biological control of insect pests, and rapid and accurate identification of the many isolates of these nematodes is important for their implementation. Eighty ten-mer random primers were screened for use in determining genetic variability among isolates of Heterorhabditis bacteriophora, H. megidis, Steinernema glaseri, S. carpocapsae, and S. feltiae. A similarity of 0-6% was observed between the members of different genera, and less than 20% similarity was observed among congeneric species. Genetic analysis using seven primers of different Heterorhabditis isolates from various parts of the world showed 24-96% similarity. These results agreed with other reports which showed many genetic differences among isolates. RAPD analysis described here can be used for the assessment of genetic variability among species and isolates of entomopathogenic nematodes.