Diagnosis- Criconematina. Body small (rarely over 0.5 mm), becoming obese in females of several genera. Cuticle thin, finely annulated (secondarily thickened and without discerible annulation in obese females), lateral field with two to four incisures, may occasionally by (sic) obscure. Female: Lip region smooth lacking prominent annules, continuous with body, with or without submedian lobes. Postcorpus large, muscular, amalgamated with broad precorpus, which may be slender in short-stylet forms. Isthmus slender, not amalgamated with basal bulb which is usually small and rounded; oesophageal glands free in body cavity only in Tumiota. Vulva a large transverse slit. Ovary outstretched, or coiled in obese females. Uterine wall thick in obese females, may form a cystoid body in Meloidoderita. Excretory cell may be abnormally enlarged to produce a gelatinous matrix in which eggs are deposited (e.g. Tylenchulus). Male: Oesophagus degenerated and stylet degenerate or absent. Bursa usually absent, if present low, adanal to subterminal (enveloping entire tail in Tylenchocriconema). Spicules setose, arcuate, with pointed tip. Hypoptygma single, usually absent. Gonoduct packed with minute sperm; testis in adult degenerates; the entire complement of sperm is probably produced just before the final moult. Juveniles: Similar to female in most details, but some juveniles lack a stylet. Ectoparasites (rarely secondarily obese females becoming endoparasites) of roots.
-Siddiqi, 2000