Definition - What does Root Maggot mean?
Root maggots are the larvae of fungus gnats. Fungus gnats resemble tiny flies. They lay their eggs in wet soil, and will appear in cases when the top layer of soil is wet for too long.
The root maggots that result will look like tiny white worms. They will eat the roots of the cannabis plants, including the taproot. This can quickly kill the plant. Root maggots are especially a problem for soil growers with overly humid grow rooms.
MaximumYield explains Root Maggot
Fungus gnats proliferate in wet conditions. They may enter the room in the first place by hitching a ride on the grower's clothing, through vents, via pets, or by contaminated soil or plant stock.
The fungus gnats themselves are small. When you are watering your plants too much, they can appear, so one solution to beating fungus gnats and their larvae—the root maggots—is to wait longer between each watering. When the top inch of soil dries out, then the maggots will naturally go away on their own.
Ways to speed up the process of getting rid of root maggots includes blowing air over the soil to dry it faster. This also prevents the gnats from flying around and being able to reproduce.
Another common method of removing the maggots is to soak the topsoil in neem oil. It is safe to use up until a few days before harvest. You can also apply diatomaceous earth DE). These two remedies are natural pest control for a variety of insects.
To avoid a fungus gnat problem altogether, hydroponics might be a viable solution that eliminates soil completely.