In the seventies the olfactory orientation of the Colorado potato beetle in response to plant odours has been studied on a walking plate, which measured 70 cm long and 23.5 cm wide, in front of a wind tunnel (Visser, 1976; Visser & Nielsen, 1977; Visser & Avé, 1978). As individual beetles moved around they frequently touched the rails on the sides and soon reached the upwind or downwind edge of the walking plate. In this setup the beetles' olfactory orientation could only be studied for a limited amount of time. Furthermore, walking tracks were affected by the limited size of the walking plate. For these reasons the first author introduced the locomotion compensator, servosphere, for further studies on Colorado potato beetle orientation. This instrument allows the beetle to walk continously without reaching any object, and enables detailed analyses of movements and walking tracks.