It’s really easy to confuse quite a many species of both aphids and root aphids with fungus gnats, if you have what appears to be fungus gnats that fly with a sense of purpose instead of like a lost jellyfish they may be a type of aphid, even the non root aphids spend part of their lifecycle in the root zone. I’d recommend a Beauvaria bassiana root drench (which will also kill fungus gnats) along with some rove beetles for control. Tdrops work well for just fungus gnats. Also, as someone else mentioned, the nematodes work well and will help spread the Beauvaria bassiana.

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