The parasitic life-cycle of Haemonchus Placei (Place) Ransom (Nematoda: Trichostrongylidae)

Abstract

The parasitic life-cycle of Haemonchus placei (Place 1893) Ransom 1911 is described and compared with that of H. contortus (Rudolphi 1803) Cobb 1898. The third ecdysis of H. placei larvae occurred 36-76 hr after infestation, and the fourth and final moult occurred 11-14 days after infestation in the majority of larvae. Many third- and fourth-stage larvae penetrated deeply into the gastric glands of the mucosa. A small proportion of larvae did not develop beyond the early fourth stage, even after the majority had become adult. The pre-patent period of H. placei was estimated to be about 11 days longer than that of H. contortus.