Experts and BHG readers answer.
Bugs on hibiscus
Do these tiny white insects fly around when you disturb them? I suspect that your hibiscus has whiteflies, a common insect that attacks this plant. They can be difficult to control, but if you are persistent in thoroughly spraying the undersides of the leaves with a broad-spectrum insecticide such as sevin or malathion, you can keep the population manageable. It will take several sprays at weekly intervals, because new ones will hatch out from eggs.