A comparative study of the infective larvae of Nematodirus species parasitic in sheep

Abstract

Three species of the genus Nematodirus have been described from sheep in Britain: N. spathiger, N. filicollis and N. battus.The infective larva of N. spathiger has been described by Monnig (1931), and in more detail by Dikmans & Andrews (1933). The infective larva of N. filicollis was described and figured by Boulenger (1915). A brief description was also given by Morgan (1930), while Maupas & Seurat (1913) figured the larva but gave no description or measurements. In the present paper, the infective larva of N. battus is described and compared with those of the other two species. However, as in the course of this study certain discrepancies were observed in the published description of the larva of N. filicollis, a redescription of the larva of this species is also given.