Discrimination of the larval stages of Echinococcus oligarthrus (Diesing, 1863) and E. vogeli Rausch and Bernstein, 1972 (Cestoda: Taeniidae).

Rostellar hooks of protoscolices from known larval stages of Echinococcus oligarthrus (Diesing, 1863) and E. vogeli Rausch and Bernstein, 1972 were compared to determine whether morphologic differences could be defined. The large and small hooks, respectively, of the two species were found to differ significantly in length (P = less than 0.0001) as well as in relative proportions. Host-related variation in lengths of hooks was not observed. Dimensions of the rostellar hooks were found to provide means for the discrimination of the larval stages of E. oligarthrus and E. vogeli, of which the latter is the cause of polycystic hydatid disease in man in South and Central America. The defined criteria were used in the identification of larvae from wild rodents and man.