Q.What can I spray on orchid with tiny bugs in soil
One orchid plant has tiny, tiny bugs in soil. One had brown eaten away trails underneath leaves. What can I spray on it? What can I spray on orchid with tiny bugs in soil? And another plant with brown trails of eaten leaf on the underside?
The tiny bugs in your soil could be fungus gnats. This article will help:
https://www.gardeningknowhow.com/special/children/fungus-gnats.htm
I would say the brown trails on your leaves are the work of leaf miners. More information on leaf miners can be found here:
https://www.gardeningknowhow.com/plant-problems/pests/insects/leaf-miner-control.htm