Biologische bestrijding van de glimslak (zonitoides arboreus) in potorchidee : Effect van koper-ionen op de glimslakken

Growers of orchids know how noxious this small species of snail (Zonitiodes arboreus) is. The snail is only approximately 0,5 cm in diameter. They spent most of their lives in growing media like bark and coco. They eat from the roots. This causes damage of the orchids. In the trails the snails were exposed to copper-ions, five dosages by means of direct contact, treated food and the treatment of Oncidium-plants, infected with the snails, with copper-ions during three months. The results showed that there was no visible effect on the snails. They behaved normally and were all alive. Weekly applications of copper-ions caused accumulation of copper in the leaves, the roots and the growing medium. Specially in the roots the levels were high. The different dosage caused no damage to the orchids. Only the growers saw some (very little) reduction in growth of the roots in comparison with the roots of the untreated plants