Heterodera graminophila n. sp. (Nematoda Heteroderae) from Grass with a Key to Closely Related Species.

Heterodera graminophila n. sp., a member of the H. goettingiana group, is described and illustrated from roots of barnyard grass, Echinochloa colonum (L.) Link, in Baton Rouge, La. This new abullate species, having second-stage larvae with only three lines in the lateral field, is most closely related to H. cyperi Golden, Rau &Cobb, 1962, and H. graminis Stynes, 1971, but differs particularly in having a small, inconspicuous anus without a circum-anal pattern and located about 20% of the cyst length from the vulval cone terminus, and a longer vulval slit averaging 45 mu in length. A key, based on cyst and larval characters, is presented for identification of the 10 Heterodera species in the H. goettingiana group.