RESUMEN
Postembryonic development of Paraphelenchus myceliophthorus has been studied. The first molt takes place inside the egg-shell; outside the latter 3 molts were revealed, dividing 2nd, 3rd, 4th stage juveniles, and the adults. Descriptions of morphology of all juvenile stages were given, as well as morphology of all molting juveniles and adults. Stages of development differ in the genital primordium structure and in body length. In juveniles of 3rd and 4th stage the sex of juvenile can be distinguished--male juveniles have cloacal primordium, whereas female juveniles have vulval primordium. In male 3rd stage juveniles the large germinal cell is situated in the posterior part of the genital primordium, whereas female 3rd stage juvenile has the large germinal cell in the anterior part of the genital primordium. Adults differ from juveniles in the presence of copulative structures--vulva in adult female and spicules in male. The adult male has caudal alae (bursa) in the form of lateral cutucular folds and 4 pairs of caudal papillae, one preanal pair at mid-spicule level and 3 postanal pairs--p1 situated just posterior to cloacal opening, p2 at mid tail, p3 and p4 on the tail terminus. An unpaired papilla is also present just anterior to the cloacal opening. Gubernaculum is present. The tracery inner tail framework supporting the spicules has been described. In females 2 pairs of tail tip tuberculi are present, and 2 ventral ones are distinctly longer than 2 dorsal ones. These tuberculi correspond to p3 and p4 pairs of papillae in male and are homologous to tail tip papillae of the Aphelenchus females, which earlier were considered to be phasmids. These 4 tuberculi are joined with 4 one-celled glands of tail terminus.
