Morphometrics and ratios of each nominal species were compared and evaluated. Primary diagnostic characters used were: the basic shape of the perineal pattern, juvenile body length and "c" ratio, and stylet lengths of females, males, and juveniles. Secondary diagnostic characters were: position of excretory pore and existence of vulval protuberance on females, number of male lateral incisures, spicule length, and position of the hemizonid in juveniles. Accordingly, the value of the perineal pattern as the major diagnostic character is deemphasized because of variability within populations and lack of sufficient objectivity in descriptions. A key to species and species groups is proposed. A statistical cluster analysis was performed to further determine relationships between species. Diagnostic characters used were: juvenile body length and "c" ratio; stylet lengths of females, males, and juveniles; spicule length and number of lateral incisures on males. Meloidogyne acrita, M. baurue
