Our condo bought two of these 3 ft Braided Hibiscus tree plants for outdoors. Though we have had a year of abundant flowering, some pests continue to cause problems. It looks like a mite or tiny black ants. We tried the dawn solution and that helped for a time. Now buds are smaller or do not open just fall off. We have no landscapers.
Braided Tropical Hibiscus
Certified GKH Gardening Expert
Neem Oil is a good treatment for insects on your Hibiscus.
Here is a couple of links with more information.