Aphids or something else?
For several weeks one of my tropical hibiscus has had clusters of these black insects on leaves (new growth) that are just emerging from the branches. I have also found them crawling on the rim of the planter - they look like small moving black dots. Earlier on I found some small black flies on a window sill close to the plant. I have sprayed several times with neem oil or insecticidal soap or a pyrethrin spray but they are back in a few days. Comments and/or suggestions would be appreciated. A neighbor also has had them on her hibiscus. The attached photo shows them after a pyrethrin spray. The ones that crawl on the rim of the planter are too small to be photographed well.
Munching on the newly emerging leaves is classic behavior for aphids. The insects in your photo all appear to be dead and misshapen. We couldn't find any intact one, but what we see looks like aphid remains or skins.
Aphids can be hard to get rid of. Stay on the attack. On nice days you can simply take them outside and hit them with a strong stream of water (or do this in the shower.) Once danger of frost is past, you can leave the plants outside and let natural predator insects move in and take care of the aphids for you
Read through our aphid webpage for more ideas: https://extension.umd.edu/hgic/aphids-flowers Or you can search
'aphids' and find more of our information.