Clare Murphy Staff asked 15 years ago
Within a few weeks of repotting my orchids (phalaenopsis) they were infested with small black flies. The flies are very small and seem to die off after a number of days.To try and control the pests I disposed of the ‘infested’ potting compost and repotted the orchids in a new compost. Before repotting I washed the leaves and roots with water. Unfortunately the flies came back after about two weeks and have multiplied rapidly.Can you suggest any insecticides that should be used? Should I repot the plants again but this time wash the plants with insecticide?