Aploparaksis kornyushini n. sp. (Cestoda: Hymenolepididae), a parasite of the woodcock Scolopax rusticola (L.), and its life-cycle.

Aploparaksis kornyushini n. sp. is described from a woodcock Scolopax rusticola L. from Lithuania, Russia (Tver' Region) and the Ukraine. Initially, one specimen of this tapeworm was described and figured by Kornyushin (1975) as A. scolopacis Yamaguti, 1935 together with another specimens belonging to the latter species. A. kornyushini n. sp. and A. scolopacis are morphologically very similar species. They can be distinguished by the slightly different length of the rostellar hooks and by the shape of the cirrus, which lacks basal bulbus in the new species. A. kornyushini can be readily distinguished from the remaining species of Aploparaksis Clerc, 1903 from woodcocks by the structure of its fully-developed embryophore, which has polar thickenings and two large or a few smaller lateral projection; this combination of characters is unknown for embryophores other Aploparaksis spp. (except for A. scolopacis). The life-cycle of A. kornyushini was studied under experimental conditions in Lithuania. The metacestodes were located under the chlorogogenous tissue of the intestine of Dendrobaena octaedra (Lumbricidae). The metacestode exhibits a pattern of postembryonal development typical for the cysticercoid modification termed an 'ovoid diplocyst'.