Nematodes belonging to Helicotylenchus are commonly known as spiral nematodes due to the form the heat killed nematode takes. Spiral nematodes are of limited economic importance but have a wide host range. There are 12 species of Helicotylenchus reported from New Zealand: H. canadensis (found under mixed Lolium perenne/ Trifolium repens pasture), H. depressus (hosted by golden sand sedge Desmoschoenus spiralis), H. digonicus (hosted by marblewood Carpodetus serratus amongst others), H. dihystera (hosted by the cabbage tree Cordykine australis and Metrosideros kermadecensis amongst others), H. erythinae (hosted by the native titoki Alectryon excelsus and Hebe sp. amongst others), H. exallus (hosted by Sarcocornia quinqueflora), H. labiatus (wide host range including chrysanthemum and carrot), H. lissocaudatus (hosted by the native tawa Beilschmiedia tawa and pigeonwood Hedycarya arborea), H. minzi (hosted by Celmisia spp. and Coprosma sp. amongst others), H. paraplatyurus (host not determined), H. pseudorobustus  (wide host range including brown top Agrostis tenuis and perennial ryegrass Lolium perenne) and H. varicaudatus (hosted by tobacco and pea amongst others).

The genus Helicotylenchus belongs to the family Hoplolaimidae which also contains the important genera Hoplolaimus, Rotylenchulus, Rotylenchus and Scutellonema.