Two New Tylenchid Nematode Species Associated With Wheat and Rice Cropping System in North India

Two new species of nematodes belonging to Tylenchida have been described. Tylenchorhynchus karnalensis n. sp. collected from rhizosphere of paddy at Kamal, Haryana, is characterised by having ventrally arcuate body when fixed, body length=0.59–0.74 mm, a=24.5–30.5, b=4.5–5.5, c=12–15, c=2.7–3.2, V%=50–56 and spear length=16–17 flm, lip region hemispherical continuous with body contour bearing three annules, stylet knobs rounded, tail subcylindrical, bearing 22–28 annules with smooth terminus, phasmids located anterior to the middle of tail. The new species is distinguished from closely related species Tylnchorhynchus ewingi Hooper 1959, and T. nudus Allen, 1955. Another new species Helicotylenchus bajoriensis n.sp. is characterised by having close ‘c’ shape body when killed, body length=0.61–0.90 mm, a=31–38, b= 8.0–9.7, b' =7–8, c=38–60, c'=0.75–1.2, V%= 57–63, spear length=22–28 flm, dorsal oesophageal gland opening located 12–16 flm, from base of stylet knobs, head conoid, continuous with body contour marked by three annules. Stylet knobs anteriorly directed, tail cylindrical with rounded terminus. The new species is distinguished from closely related species. Helicotylenchus impar Prasad, Khan and Chawla, 1965 and H. goodi Tikyani, Khera and Bhatnagar, 1969.