ABSTRACT
Typical Tylenchidae are slender; they have a nonsclerotized head framework; a short, delicate stylet; and a short, nonoverlapping esophagus; the intestine contains 20–24 or more cells arranged in pairs; the female reproductive system is monodelphic, prodelphic with a quadricolumellar uterus and a short, if any, postvulval uterine sac; the tail is elongated. The assemblage of all species having the characteristics mentioned yield more than 50 nominal genera, 17 subfamilies, and 6 families. In Geraert and Raski and Maggenti et al., the five families are considered synonyms of Tylenchidae, the 17 subfamilies are reduced to 5, and 19 genera are considered junior synonyms of existing ones. A detailed study of the lip area with SEM, of the female reproductive system, and of some morphometric relationships helped to diagnose five subfamilies. Female reproductive system prodelphic, straight. Spermatheca shape apparently variable even within a species: from entirely in line to partly in line and partly offset; postvulval uterine sac short.
