The most effective way to control the adults is to use a physical barrier as they cannot fly from plant to plant. Stand potted plants on upturned pots sat in saucers of water - the adults can't swim. Or surround the pots with Barrier Glue available from Agralan - the adults cannot walk across it. Physical barriers on top of the soil or compost also work very well. The company has shown in preliminary work that by placing one of these around the stem or collar of the plant, and one in the base of the pot, the adult is again unable to lay its eggs.
Larger mats are also available for plants growing in the garden.
The dilution rate is one part Armillatox to 500 parts water. Armillatox does not harm beneficial predators. It is also very cost effective - a 1 litre pack will dose the surface of over 11,000 13cm pots. Then turn to my whitefly control page.