Heterorhabditis Poinar, 1976

Type species: H. bacteriophora Poinar, 1976

21 valid species were listed in catalogue 2011. Here, four new species are added and three species names mentioned in catalogue 2011 are shown to be new synonyms, resulting in 22 species in this genus taxon now.

• H. beicherriana Li, Liu, Nermuť, Půža &Mráček, 2012 – Beijing area, China; soil from a cherry orchard, isolated with the Galleria mellonella baiting technique.

• H. noenieputensis Malan, Knoetze & Tiedt, 2014 (type isolate SF669) – on the farm Springbokvlei, near Noenieput, South Africa; soil from beneath a fig tree, using the trapping method with larvae of Galleria mellonella.

• H. ruandica Machado, Bhat, Abolafia, Muller, Bruno, Fallet, Arce, Turlings, Bernal, Kajuga, Waweru & Toepfer, 2021 (type isolate Rw14_N-C4a) – near Kanyirandori village, Nyamagabe district, Southern province, Rwanda; cropland, isolated from soil samples by the Galleria baiting technique.

• H. zacatecana Machado, Bhat, Abolafia, Muller, Bruno, Fallet, Arce, Turlings, Bernal, Kajuga, Waweru & Toepfer, 2021 (type isolate MEX-39) – Villanueva, Zacatecas, Mexico; soil from maize field, isolated by the Galleria baiting technique.

I accept the synonymisations given by Dhakal et al. (2021) for the following three species dealt with in catalogue 2011.

• H. baujardi Phan, Subbotin, Nguyen & Moens, 2003 syn. H. somsookae Maneesakorn, An, Grewal & Chandrapatya, 2015 (= H. sp. MP68) – Amphoe Srisawat, Kanchanaburi province, Western Thailand; soil.

• H. indica Poinar, Karunakar & David, 1992 syn. H. gerrardi Plichta, Joyce, Clarke, Waterfield & Stock, 2009

– H. pakistanensis Shahina, Tabassum, Salma, Mehreen & Knoetze, 2016 – Malir, Karachi, Pakistan; soil around the roots of Bermuda grass (Cynodon dactylon), isolated by baiting with Galleria mellonella larvae.

– H. brevicaudis Liu, 1994

• H. taysearae Shamseldean, Abou El-Sooud, Abd-Elgawad & Saleh, 1996 syn. H. sonorensis Stock, Rivera-Orduño & Flores-Lara, 2009

So far sequence data were available, the species group into three clades (Dhakal et al. 2021, Machado et al. 2021).

Bacteriophora clade (5 species): H. bacteriophora, H. beicherriana, H. georgiana, H. ruandica, H. zacatecana.

Indica clade (7 species): H. amazonensis, H. baujardi, H. floridensis, H. indica, H. mexicana, H. noenieputensis, H. taysearae.

Megidis clade (6 species): H. atacamensis, H. downesi, H. marelata, H. megidis, H. safricana, H. zealandica.

Not assigned to a group (4 species): H. egyptii, H. hambletoni, H. hoptha, H. poinari.