Diagnosis: Female (FIG.1) without phasmids, tail (T) shorter than anal body width (ABW) (T/ABW=0.52-0.81); oviparous but some eggs often retained in the body. Male smaller than female (FIG.2) , posterior part usually with one single and eleven pairs of genital papillae; phasmids not observed, tail terminus rounded or with mucron. Infective juvenile (FIG.3) with phasmids small or inconspicuous, tail conoid and much shorter than esophagus (at most 65% of esophagus length), ratio c greater than or equal to 10.

Type species: Steinernema kraussei (Steiner, 1923) Travassos, 1927.