My indoor hibiscus is healthy and producing flowers, but as the flowers start dying we are finding little black bugs on them.
Certified GKH Gardening Expert
Sounds like your hibiscus is affected by aphids. Try treating the plant with neem oil, which is not only effective in eradicating these pests but safe as well. Here is an article that you may find helpful: https://www.gardeningknowhow.com/problems/pests/neem-oil-uses.htm