First report of entomopathogenic nematode Heterorhabditis bacteriophora (Rhabditida: Heterorhabditidae) from South Africa

We present the first report of Heterorhabditis bacteriophora entomopathogenic nematodes isolated from sandy loam soil obtained from Walkerville, South of Johannesburg, Gauteng province, South Africa. A survey was conducted to collect soil samples and isolate entomopathogenic nematodes between 2012 and 2016. Entomopathogenic nematodes are insect-killing microscopic worms found in soil and have a symbiotic relationship with insect pathogenic bacteria. Molecular and morphological techniques including genomic DNA extractions, polymerase chain reaction and sequencing of the 18S rDNA, phylogenetic analysis, light microscopy and scanning electron microscopy were used to identify entomopathogenic nematodes from the collected soil samples. H. bacteriophora was recovered in one out of 80 soil samples from an uncultivated grassland and the frequency of its isolation from soil samples in our study was 2%. Phylogenetic tree analysis revealed that the South African isolate was grouped with the strain H. bacteriophora strain 56-C. H. bacteriophora. The body length, body width and tail of the isolate are slightly shorter than the previously described H. bacteriophora. This is the first H. bacteriophora species to be isolated and reported from South African soil and future studies will explore its potential as a biological control agent of problematic insect pests in agricultural industries.

Automated summary

This study reports the isolation of Heterorhabditis bacteriophora entomopathogenic nematodes from sandy loam soil in Walkerville, South Africa, marking the first discovery of this species in South African soil. Molecular and morphological techniques were used for identification, and future studies will explore the potential of this nematode as a biological control agent for agricultural pests.