ABSTRACT
The citrus nematode, Tylenchulus semipenetrans, is the only species known to be of major economic importance to agriculture and it is worldwide in distribution. Esophageal glandular bulb small, offset from intestine. Ectoparasitic mostly on roots of higher plants, in some cases under bark of perennial host roots; exceptionally on leaves and in crowns. Young females penetrate deeper into the root tissues where a feeding site is developed around the head of the female. Immature female: Body vermiform with distinct transverse striae. Lip region of immature female is conoid-rounded, smooth, continuous with body; labial disk absent; labial framework moderately sclerotized.
