IDENTIFICATION OF 2ND-STAGE JUVENILES OF TYLENCHULUS SPP ON THE BASISOF POSTERIOR BODY MORPHOLOGY

Tail lengths of live 52 were measured in two, three, and eight populat ions of Tylenchulus graminis, T. palustris and female T. semipenetrans , respectively. Except for one population of T. palustris from Costa R ica and two populations of female T. semipenetrans from Italy, all oth er populations were from Florida, U.S.A. Ranges in tail length values were 59.5-72.5, 42.0-54.0, and 55.0-70.0 mu m for T. graminis, T. palu stris and female T. semipenetrans J2, respectively. The canonical disc riminant analysis for this character allows the separation of T. palus tris J2 from T. graminis and female T. semipenetrans J2, which did not differ. The nearly hyaline portion of the posterior body without fat globules > 3 mu m diam was measured in selected populations of T. gram inis, T. palustris, and female T. semipenetrans J2 from Florida. The r anges in values for this class of measurements were 59.0-75.0, 24.5-59 .0, and 35.0-60.0 mu m for each of the three species, respectively. An other class of measurements of the nearly hyaline portion without fat globules > 3 mu m diam was also taken in selected populations of the t hree species from Florida. The ranges in values for this class of meas urements were 64.0-78.0, 42.0-59.0, and 40.0-64.0 for each of the thre e species, respectively. The canonical analysis for all characters, in cluding tail length, allows the separation of T. graminis J2 from T. p alustris and T. semipenetrans J2, which did not differ. The remaining species of the genus, T. furcus has 52 with a characteristic furcate t ail tip, unlike the tapered tails of other Tylenchulus species.