HETERODERA AUCKLANDICA SP-N (NEMATODA, HETERODERIDAE) FROM A NEW-ZEALAND NATIVE GRASS, WITH NOTES ON THE SPECIES OF THE HETERODERA-AVENAE GROUP

Heterodera aucklandica sp. n. is described from the New Zealand native grass Microlaena stipoides (Labill.) R.Br. The cyst nematode species belongs to the H. avenae group, a heterogeneous group of species chara cterised by a vulval slit length in the range 4.5-20 mu m. Within the H. avenae group, H. aucklandica resembles most closely Heterodera aven ae Wollenweber, 1924 from which it can be distinguished by the longer tail and longer and thinner hyaline part of the tail, and by the flat anterior face of the stylet knobs of the second stage juvenile. The ta xonomic status of the species of the H. avenae group is discussed and their key taxonomic features are presented in a table.