Morphometrical variability in 3 : Observations on HeZicotyZenchus Steiner, 1945. African populations of HeZicoty2en.chus dihystera and- considerations on related species

SUMMARY Multivariate analyses were used to compare ten African populations of Helicotylenchus to i) a typical Helicotylenchus dihystera from California, ii) two other African Helicotylenchus very different from H. dihystera. The analyses inferred that no difference could be found in morphometrical characteristics among the ten African populations and between those and the typical H. dihystera. It 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. morasii and H. paracanalis 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. paracanalis 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.