How do I get rid of whiteflies?
The Gardener’s Answer
Hello, Sue in Florida: There are many different species of whiteflies and within each species there is a wide range of host plants that these sap-sucking insects attack. They all thrive in warm environments and excrete honeydew as they feed that leaves the foliage sticky and can attract ants. Whiteflies do have a few natural enemies such as lacewings but control can be difficult in extreme numbers. Indoors they will not likely have any natural enemies to help reduce the population so you are left with other options. Sticky traps are effective in controlling whiteflies as the adults are attracted to the traps; they eventually die and are not able to reproduce. The idea here is to eliminate as many as possible to stop the cycle. It will take a while as you may have many generations and they have to reach the adult stage before the sticky traps will work. Wiping or spraying down the underside of the foliage will also help reduce the numbers. Lastly, insecticidal soaps and oils are an option but are only effective if sprayed on the nymphs and these can potentially kill natural enemies. As with all products, make sure to follow recommended application rates. Once a plant has whiteflies it can be an ongoing battle to eliminate them completely but keeping the numbers down will help keep your plant healthy. If there are leaves that look unsightly or have a large number of whiteflies living on them you can go ahead and remove/dispose of them.