Genus Rotylenchulus
Linford &Oliveira, 1940
Syn: Leiperotylenchus Das, 1960
Spyrotylenchus Lordello & Cesnik, 1958
(Spirotylenchus in Lordello & Cesnik, 1958
=lapsus calami, incorrect original spelling)

Diagnosis: Rotylenchulinae.
Juveniles, males and young females vermiform, arcuate to spiral upon relaxation.  Mature female kidney-shaped, with an irregular, less swollen neck, a postmedian vulva and a short pointed tail.  Cuticle annulated.  Lateral fields each with four incisures, non-areloate, obliterated in mature female.  Cephalic region high, continuous.  Stylet in juveniles and female two to three times cephalic region width long.  Orifice of dorsal oesophageal gland usually about one stylet length behind stylet base.  Subventral glands in the normal position, dorsal gland shifted laterally to subventrally, former much longer than the latter.  Immature female: Vermiform, migratory (has been mistaken for adult stage and formed the basis for the proposal of new genera, Spyrotylenchus, Leiperotylechus). Ovaries paired, with double flexures.  Tail elongate-conoid, with prominent hyaline terminal portion.  Male: Stylet and oesophagus regressed.  Tail similar to that of young female; bursa subterminal, low, not quite projecting beyond tail contour in lateral view (hence mistakenly reported absent in R. stakmani (=R. reniformis)). Phasmids located on tail in its anterior region.  Spicules slender, lacking distal flanges.  Gubernaculum fixed, devoid of titillae and telamon.  Cloacal lips pointed, not forming a tube; hypoptygma absent.  Juvenile tail more rounded terminally and with shorter hyaline terminal portion than that of a female. .

Type species:
    Rotylenchulus reniformis Linford & Oliveira, 1940
        syn. Tetylenchus nicotiana Yokoo & Tanaka in Tanaka & Tsumagori, 1954
              Rotylenchulus nicotiana (Yokoo & Tanaka in Tanaka & Tsumagori) Baker, 1962
               (Nakasono & Ichinohe (1967) and Dasgupta et al. (1968) also proposed this combination)
              Rotylenchus elisensis Carvalho, 1957
              Helicotylenchus elisensis (Carvalho) Carvalho, 1959
              Rotylenchulus elisensis (Carvalho) Siddiqi, 1986
              Spyrotylenchus queirozi Lordello & Cesnik, 1958
              Rotylenchus queirozi (Lordello & Cesnik) Sher, 1961
               Leiperotylenchus leiperi Das, 1960
              Rotylenchus leiperi (Das) Loof & Oostenbrink, 1961
              Rotylenchulus stakmani Husain & Kahn, 1965
 

Other species:
    Rotylenchulus anamictus Dasgupta, Raski & Sher, 1968
    R. borealis Loof & Oostenbrink, 1962
    R. brevitubulus Van den Berg, 1990
    R. clavicaudatus Dasgupta, Raski & Sher, 1968
    R. leptus Dasgupta, Raski & Sher, 1968
    R. macrodoratus Dasgupta, Raski & Sher, 1968
    R. macrosoma Dasgupta, Raski & Sher, 1968 (original spelling macrosomus)
    R. parvus (Williams, 1960) Sher, 1961
        syn. Helicotylenchus parvus Williams, 1960
    R. sacchari Van den Berg & Spaull, 1981
    R. variabilis Dasgupta, Raski & Sher, 1968

Note- Rotylenchulus macrosoma is generally similar to R. borealis in morphology, host preference and host tissue reaction.  By its feeding, R. macrosoma incites hypertrophy of pericycle cells which form a syncytium.  A feeding tube within the enlarged feeding cell is formed. Rotylenchulus macrodorus, on the other hand, incites a single uninucleate giant cell within the host tissue (Cohn & Mordechai, 1988)

ETYMOLOGY  Latin diminutive of Rotylenchus.

The type species was found parasitizing cowpea (Vigna sinensis Endl.) on the Island of Oahu, Hawaii, USA
(Description- Siddiqi, 2000)