Beha vioural responses of spiral nematode, Helicotylenchus dihystera during attraction and feeding on buffel grass roots

Analysis of tracks formed by the nematode, Helicotylenchlls dihystera during attraction towards the host root, Cenchrus ciliaris, and observations on their feeding behaviour suggest that the velocity of nematode movement graduaIly increases as they approach host root. The increase in velocity is by decreasing wave pitch, wave per body length, or by increasing wave frequency. Some deviations from the straight path may be due to the efforts of the nematode to assume suitable feeding postures. During feeding, thigmotactic response shows that the lips and stylet act as sensory and mechanical devices.