Morphometrical variability in Helicotylenchus Steiner, 1945. 3: Observations on African populations of Helicotylenchus dihystera and considerations on related species.

Multivariate analyses were used to compare ten African populations of Helicotylenchus to i ) a typical Helicotylenchus dihystera from California, i i ) two other African Helicotylenchus very different from H. dihystera. The analyses inferred tha t no difference could be found in morphometrical characteristics among the ten African populations and between those and the typical H . dihystera. I t was concluded that, in spite of the high variability of several criteria commonly used in the taxonomy of Helicotylenchus, it was possible to identify the African populations as H . dihystera. Revised descriptions of H. dihystera, H . morasi i and H . paracanal is are presented. H. punicae Swarup & Sethi, 1968, H . dihysteroides Siddiqi, 1972, H. flatus Roman, 1965, H . rotundicauda Sher, 1966, H. glissus Thorne & Malek, 1968, and H. teleductus Anderson, 1974, are proposed as new synonyms of H . dihystera ; and H . trivandranus Mohandas, 1976, as a new synonym of H . paracanal is Sauer & Winoto, 1975. H . microlobus Perry, 1959, and H . teres Gaur & Prasad, 1972, are reinstalled as valid species. H. caribensis Roman, 1965, B. borinquensis Roman, 1965, and H . leucernis Khan & Ahmad, 1970, are considered species inquirendae. H. sagitovi is proposed as a new name for H . orientalis Sagitov et al., 1978, homonym of H . orientalis (Siddiqi & Husain, 1964) Geraert, 1976.