Little black flies are flying around, on and off the plant.
Most insects can be treated with Neem Oil.
Here are some links with more information.
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
https://www.gardeningknowhow.com/houseplants/spider-plant/sticky-spider-plant-leaves.htm
There is a black, tiny insect infestation under and around new leaves and buds of hibiscus indoors. My mature hibiscus plant recently developed tiny dark spots, lots of them, under leaves and new growth. Used insecticidal soap and cut plant back to only new buds but it's reappearing on new leaves.
It may be aphids. This article will help:
https://www.gardeningknowhow.com/plant-problems/pests/homemade-aphid-control-a-natural-way-to-kill-aphids.htm
It might also be several other bugs, but aphids are the most common. Regardless of the bug, all of the common pests on hibiscus can be treated with neem oil. Here is more information on neem oil:
https://www.gardeningknowhow.com/problems/pests/neem-oil-uses.htm
My indoor Christmas cactus has gnats. How do I get rid of them?
These articles will help you.
https://www.gardeningknowhow.com/plant-problems/pests/insects/fungus-gnats.htm
How do I get rid of scale on a houseplant?
This article will help you:
https://www.gardeningknowhow.com/plant-problems/pests/insects/control-plant-scale.htm
How do I get those tiny flies or gnats out of the soil in my planters?
Those are probably fungus gnats. See this article for what to do:
https://www.gardeningknowhow.com/plant-problems/pests/insects/fungus-gnats.htm
This technique would probably work if you want to kill off the gnats before planting in the planters:
If the soil isn't in the planters yet, you could solarize it inside a black trash bag.
I have a rubber plant in my house. After reading up on this plant, I see that they are susceptible to spider mites. Can I use a miticide as a preventative before spider mites appear?
Spider mites are incredibly tiny, almost invisible to the naked eye. Using a miticide on your plant may be a good preventative if your concerned there may be an infestation.
Here is an article on miticdes and how to choose the right one for your plant;
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/using-miticide-on-plants.htm
I have a indoor houseplant that has large green leaves, approximately 12" long and is about 30" tall. I just noticed that it has small little white eggs around and in the dirt and when I took one of these eggs out and smashed it, a small spider came out. What can I do to get rid of these so they don't kill my plant?
And here is our article about removing spiders from homes and gardens:
https://www.gardeningknowhow.com/plant-problems/pests/insects/spider-garden-pests.htm
Fortunately, spiders will not kill plants, and they often benefit plants by eating insects that would attack plants. However, if you understandably don't want spiders in your house, the best way to remove them would be to remove all the eggs you can find. Then, look for webs on and around your houseplants and remove those too. That should take care of the problem or at least cut down the spider population.