Abstract: For an infestation of scab to develop through its initial stages requires the presence of prolonged periods of leaf surface wetness to enable the spores to germinate. Apparatus is provided which monitors the ambient temperature and humidity to detect the occurrence of periods of leaf wetness sufficient to permit the initial development of an infestation. When the occurrence of such a period of wetness is detected, the apparatus changes its operating state to indicate the progress of the infestation through its secondary stages, this progress being dependent on the ambient temperature but not the wetness of the leaves. The apparatus follows the progress of the infestation by means of a monitoring device which generates a pulsed signal whose frequency is dependent on the ambient temperature and humidity, the pulses of this signal being then counted in counter means and selectively displayed on a display.

Abstract: An apparatus for use in monitoring the numbers of a selected species of insect comprising one or more traps into which is put a synthesized pheromone to attract that particular insect. Each trap has a grille comprising a plurality of bars between which is applied a high voltage by means of a high voltage generator, so that when an insect of the selected species tries to enter the trap it touches adjacent bars and is electrocuted by the electric discharge between them. This discharge is detected by a discharge detector connected to the trap and the detector passes a signal to a transmitter which transmits it to a central receiver equipped with a discriminator for ignoring signals other than those from the transmitter and for passing the signals representing discharges to a pulse counter whereby a total of the number of insects trapped in a given time can be obtained at a central station without visiting each trap.