[Systematics of Secernentea]

Suborder Cephalobina

• Family Cephalobidae
  Genus: Acrobeles, Acrobeloides, Cephalobus, Cervidellus, Chiloplacus, Eucephalobus, Pseudoacrobeles, Nothacrobeles, Zeldia
• Family Panagrolaimidae
  Genus: Halicephalobus, Panagrellus, Panagrobellus, Panagrolaimus
• Family Brevibuccidae
  Genus: Plectonchus

Suborder Rhabditina

• Family Bunonematidae
  Genus: Bunonema
• Family Diploscapteridae
  Genus: Diploscapter
• Family Rhabditidae
  Genus: Caenorhabditis, Cruznema, Mesorhabditis, Protorhabditis, Rhabditella, Rhabditis, Teratohabditis

Suborder Diplogastrina

• Family Cylindrocorporidae
  Genus: Goodeyus
• Family Diplogastridae
  Genus: Aduncospiculum
• Family Neodiplogastridae
  Genus: Diplenteron, Pristionchus

Suborder Aphelenchina

• Family Aphelenchoididae
  Genus: Aphelenchoides, Pseudaphelenchoides, Seinura
• Family Aphelenchidae
  Genus: Aphelenchus, Paraphelenchus

Suborder Tylenchina

• Family Heteroderidae
  Genus: Heterodera, Meloidogyne
• Family Pratylenchidae
  Genus: Pratylenchus, Nacobbus, Radopholus, Zygotylenchus
• Family Belonolaimidae
  Genus: Belonolaimus
• Family Hoplolaimidae
  Genus: Helicotylenchus, Hoplolaimus Rotylenchus, Rotylenchulus
• Family Criconematidae
  Genus: Hemicriconemoides, Criconemoides
• Family Tylenchidae
  Genus: Tylenchus, Filenchus, Aglenchus, Psilenchus, Boleodorus
• Family Anguinidae
  Genus: Ditylenchus, Anguina

Suborder Teratocephalina

• Family Teratocephalidae
  Genus: Teratocephalus