Partial isolation of a water soluble pheromone from the sugar beet cyst nematode, Heterodera schachtii, using a novel bioassay

The sex pheromone of female Heterodera schachtii, the sugar beet cyst nemat ode, was partially isolated using high performance liquid chromatography (H PLC). Female-conditioned medium (FCM), produced by incubating 20 H. schacht ii females in 1 ml of ultrapure water, attracted males in a concentration d ependent manner. The attractive material was not contained within the femal e gelatinous matrix and did not attract second stage juveniles (J2). Charac terisation of FCM revealed that the attractive material was water soluble a nd heat stable. Male H. schachtii exhibited stylet thrusting behaviour upon exposure to FCM, and this behaviour was used as a novel indicator of biolo gical activity.