White bugs on hibiscus plants are not only unsightly, but they also can harm the plant's growth and development of beautiful hibiscus flowers. Make a positive ID of the pest before proceeding with treatment.
Little white bugs on hibiscus plants are usually aphids. They come in white, black or green and gather on the flower stems and buds in order to feed. They do so by inserting a beak-like stylet into the plant and sucking out nectar. Aphids excrete a clear sticky substance called honeydew and reproduce quickly by laying eggs on the plant.
Another kind of small white bug you may find on hibiscus plants is the white fly. White flies congregate on the undersides of hibiscus leaves and feed on the plant's nectar. They leave behind clear, sticky excrement called honeydew that attracts black spores that stick to the plant, leaving it stained and unattractive. If you shake a white fly-infested hibiscus, the flies fly around wildly for a few seconds before settling right back down on the plant.
It is best to treat hibiscus plants for aphids even before an infestation occurs. There are pesticides that you can administer through the tree's water supply. The pesticide will be absorbed by the roots, circulate with the plant's nectar and kill aphids upon ingestion.
Treatment of white flies depends on how established the pest is on the plant. If just settling in, you can remove the infested leaves. If more established, there are high-pressure water and oil sprays that displace the bugs and dehydrate them. If that doesn't work, you can resort to pesticides.