SPECIMENS OF THE XIPHINEMA AMERICANUM-GROUP (NEMATODA: DORYLAIMIDA) ON THE TERRITORY OF THE FORMER YUGOSLAVIA

Four species of the Xiphinema americanum-group, X. incertum Lamberti, Choleva et Agostinelli, X. pachtaicum (Tulaganov) Kirjanova, X. simile Lamberti, Choleva et Agostinelli and X. taylori Lamberti, Ciancio, Agostinelli et Coiro were found in the territory of the former Yugoslavia. In order to confirm species identification, cluster analysis (CA) was used to study the relationship between X. incertum, X. pachtaicum, X. simile and closely related species X. californicum Lamberti et Bleve-Zacheo, X. intermedium Lamberti et Bleve-Zacheo and X. opisthohysterum Siddiqi on the one hand and X. taylori and X. brevicolle Lordello et da Costa, X. diffusum Lamberti et Bleve-Zacheo, X. parvum Lamberti, Ciancio, Agostinelli et Coiro and X. pseudoguirani Lamberti, Ciancio, Agostinelli et Coiro on the other hand. Measurements used in CA were taken from 23 populations found on the territory of the former Yugoslavia and 34 populations from literature. CA confirms the identification of the four above mentioned species. Morphological characteristics, morphometrics and distribution of the species are presented. The use of value c' is suggested as a new distinguishing criterion instead V in paragraph 11 in the dichotomous key of Lamberti and Carone 1991) far separating closely related X. opisthohysterum from X. simile.