DESCRIPTION OF TYLENCHORHYNCHUS-ZAMBIENSIS N-SP (NEMATA, TYLENCHIDAE)FROM ZAMBIA

Tylenchorhynchus zambiensis n, sp., associated with roots of maize (Ze a mays L.) in Zambia, is described and illustrated. Females of this bi sexual species are characterized by haring a body length of 512-648 mu m; a low, rounded, offset head region bearing 4 to 5 annuli; stylet 1 3.3-15.0 mu m long; tail with 21-32 ventral annuli, smooth tail tip; a nd presence of a post-anal intestinal sac. Tylenchorhynchus zambiensis n. sp. is most similar to T. brassicae Siddiqi, 1961; T. goffarti Stu rhan, 1966; T. ventrosignatus Tobar-Jimenez, 1969; T. quaidi Golden, M aqbool & Handoo, 1987; and T. namibiensis Rashid & Heyns, 1990. It dif fers from T. brassicae by the presence of a post-anal extension of the intestine, a shorter stylet, absence of areolation in the lateral fie ld, and the shape of the female tail. Tylenchorhynchus zambiensis n. s p. differs from T. goffarti by having fewer head annuli (4-5 vs. 6-7), a post-anal intestinal sac, and ratio a (26.7 vs. 33.0). Tylenchorhyn chus zambiensis n. sp, can be distinguished from T. ventrosignatus by ratio a (26.7 vs. 31.5), an obscure hemizonid, the excretory pore near mid median bulb vs. anterior to bulb in T. ventrosignatus and the abs ence of a wave-like structure near the vulva. It differs from T. quaid i by having a rounded head region, presence of a post-anal intestinal sac, and lack of areolation in the lateral field. Tylenchorhynchus zam biensis n. sp. differs from T. namibiensis by a smaller body size, rat io a (26.1 vs. 43.3), ratio c (13.6 vs. 19.6), stylet length (14.0 vs. 17.0), number of annuli in the head region (4-5 vs. 6-9) and absence of areolation in the lateral field.