Multiple nucleotide sequences representing all of the known species and subspecies of Xenorhabdus and Photorhabdus were downloaded from the NCBI database (http://blast.ncbi.nlm.nih.gov/Blast.cgi), aligned with sequences from the study isolates using ClustalW (Thompson et al., 1994) using MEGA software version 6.0 (Tamura et al., 2013).