Bestrijding van weekhuidmijten in gerbera

Abstract

Nine species of Phytoseiidae were evaluated as predators of Tarsonemus violae (Schaarschmidt) and the broad mite Polyphagotarsonemus latus (Banks) on gerbera plants in experimental and commercial greenhouses. Amblyseius cucumeris, Amblyseius swirskii, Typhlodromips montdorensis and Amblyseius andersoni appeared to possess the best abilities to control tarsonemids in this crop. These species showed good survival and reduced mite densities at low levels directly after their releases. However, curative releases did not effectively eliminate tarsonemids and the predators could not keep pests density below economic damage threshold year round without further releases. The importance of repeated introductions of suitable predators at an early stage of infestation was demonstrated in the experiments. We recommend releases of A. swirskii, A. cucumeris and T. montdorensis