Molecular identification of a Heterorhabditis entomopathogenic nematode isolated from the northernmost region of South Africa

Entomopathogenic nematodes (EPNs) are among the frequently used and commercialized bio-pesticides. However, they are restricted in their infectivity, persistence, storage, and cost of production. One of the methods used to improve this is a continuous search for new isolates with significant behavioral and physiological characteristics. A novel EPN isolate, Heterorhabditis zealandica strain ETL, isolated from South Africa (GPS co-ordinates − 24.849721 and 28.336980) is described and studied against late-instar of Galleria mellonella (L.) and Tenebrio mollitor (L.) larvae. The morphological and molecular studies indicated this isolate as a Heterorhabditis strain. The comparison of sequences of the internal transcribed spacer (ITS) region, the 18S rRNA gene, and the D2-D3 region of the 28S rRNA gene with available sequences of other described species within the genus indicate the isolate as a new Heterorhabditis zealandica strain. The phylogenetic analysis of the sequence data places strain ETL, closest to H. zealandica strain Bartow (GU174009) in the Heterorhabditis group. This EPN was lethal to G. mellonella and T. mollitor; as infections occurred within 24–96 h. Fifty percent of the larvae population were killed within 24 h and 100% after 96 h.