They weaken plants by sucking nutrients from leaves. Their worm stage will destroy young plants and cuttings roots, and will kill the young plants.
Yes.
Maybe
Bugs that attack cilantro plants are fungus gnats.
Yes.
Any plant can potentially as most fungus gnats breed in over watered plant soil and not the plant itself.
Fungus gnats can be a nuisance to some people. They can be eliminated by the use of a common insect repellent.
No, gnat infestations generally do not kill indoor apple tree saplings. They are just fungus gnats from the soil as a result of overwatering. Cutting back on watering amounts and times should make the fungus gnats die off.
It depends on what kind of bugs you are trying to kill. Soap and water works well on most soft bodied insects. For example spidermites, and fungus gnats.
Yes.
Plants produce chemicals that kill areas of plant tissue infected by a fungus
Yes, it will also hurt everyone who uses the marijuana.
They are just fungus gnats from over watering. Set it outside & dry it out some & they will disappear.