Mesorhabditis Osche, 1952

Type species: Rhabditis spiculigera Steiner, 1936

34 valid species were listed in catalogue 2011. Here five new species are added.

Monhystera clade (now 18 species)

Besides the vestigial bursa, the following characters are apomorphic: low frequency of males, small sperm cells, pseudogamy, females produced by gynogenesis and males by amphimixis (Launay et al. 2020). – Distribution map for several species in Launay et al. (2020).

• M. bifurcata Launay, Félix, Dieng & Delattre, 2020 (type isolate JU2902) – Botanical Garden University of Florence, Italy; from rotting pseudostem of Japanese banana ( Musa basjoo).

• M. denticulata Mahboob & Jahan, 2021 – Domariaganj, district Siddharthnagar, Eastern Uttar Pradesh, India; from a larva of a longhorn beetle ( Cerambycidae) inside the dead log of North Indian rosewood ( Dalbergia sissoo).

• M. okuensis Launay, Félix, Dieng & Delattre, 2020 (type isolate JU3143) – Oku Mountain, Cameroon; from rotting wood.

Spiculigera clade (now 21 species)

This might be a paraphyletic group (Launay et al. 2020).

• M. acidophila Borgonie, Dierick, Houthoofd, Willems, Jacobs & Bert, 2010 – sulfur cave Cueva de Villa Luz, near Tapijulapa, Tabasco, Mexico; in extreme acidic conditions of snottites (mucuous mats of extremophiic bacteria hanging from the walls and ceiling).

• M. acuticauda Ahmad, Shah & Mahamood, 2010 – Jawahar Park, Aligarh, Uttar Pradesh, India; from farmyard manure.