Kill Fungus Gnats Naturally Control Larvae with BTI To kill fungus gnats naturally, use BTI. Fungus gnats are closely related to mosquitoes, so fungus gnat larvae are effectively killed by BTI. (BTI is a naturally occurring bacterium that is deadly to mosquito larvae AND fungus gnat larvae.) BTI, which is short for Bacillus thuringiensis israelensis, is deadly to mosquito larvae and fungus gnat larvae but harmless to other living things. The bacterium is nature's way of keeping fungus gnat and mosquito populations down. But fortunately, BTI has no effect on other insects (such as bees and butterflies). Nor does it harm animals, fish, birds, plants, pets or people. BTI is the active ingredient in top-selling Mosquito Bits®, which is approved for the control of fungus gnats. To kill fungus gnat larvae, simply shake the granular Mosquito Bits® onto the potting soil in houseplants. Also use it on other container-grown plants including vegetables and herbs. Mosquito Bits contain BTI to kill fungus gnat larvae and mosquito larvae. This product is harmless to people, pets, beneficial insects, fish and wildlife. Soak Mosquito Bits in Water Here's another easy way to kill fungus gnats naturally with BTI. Make Mosquito Bits tea! Just mix 4 tablespoons of Mosquito Bits® in 1 gallon of water. Let the Bits soak for 30 minutes to remove the BTI, then skim off the floating granules. (You can also place the Bits in a nylon stocking prior to immersing them in water. That makes it easier to remove the granules, which can be composted or discarded.) Now stir or shake the water to make sure the BTI is thoroughly mixed in. Then use the BTI tea to water the soil or potting mix of houseplants and container plants. This treatment controls fungus gnat larvae present in the soil at the time of application. For best results, use your Mosquito Bits/BTI tea solution within 48 hours. Repeat this process weekly for three weeks. If fungus gnats reappear at a later time, simply repeat this treatment again. Because fungus gnats can be an ongoing problem, keep a container of Mosquito Bits with your other gardening supplies.
