Natural Fungus Gnat Control
BTI and organic horticultural oil control pesky fungus gnats
Anyone who has grown houseplants has probably dealt with fungus gnats. Adult fungus gnats are tiny flying pests that can swarm like an annoying black cloud whenever an infested houseplant or outdoor potted plant is moved.
Fungus gnats (Bradysia species) are small, mosquito-like insects that commonly infest the growing medium in which houseplants and outdoor potted plants grow. Often, when outdoor plants are brought indoors for the colder months, fungus gnats harbored in the potting mix are brought indoors, where they can quickly infest the soil of other houseplants.
Fungus gnats can be difficult to control. They thrive in moist potting soil, where they lay their eggs. After the eggs hatch, fungus gnat larvae live in the top two to three inches of the potting soil. In the larval stage, the fungus gnat maggots can cause plant damage by eating plant roots. After about two or three weeks, the fungus gnat maggots pupate in the potting soil to become the tiny black adult gnats that fly erratically when a potted plant is moved.
Letting the potting soil dry out between watering helps control fungus gnats. But sometimes more aggressive measures are needed to control the pests. Fortunately, there are now natural, non-chemical solutions that kill fungus gnat infestations.
Kill fungus gnat larvae with BTI
Because fungus gnats are closely related to mosquitoes, fungus gnat larvae are effectively killed by BTI—the naturally occurring bacterium that is deadly to mosquito larvae. BTI, 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 it 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 and other container-grown plants—including vegetables and herbs. Mosquito Bits® can also be mixed with potting soil prior to planting. When the plants are watered, the BTI in the Mosquito Bits® will be released. After subsequent watering, the BTI is washed below the soil surface. Fungus gnat larvae feed on the BTI and die.
Kill adult fungus gnats with horticultural oil
There is also an environmentally friendly, organic way to kill infestations of adult fungus gnats. Summit® Year-Round® Spray Oil is a light-weight horticultural oil that effectively controls a wide variety of insect pests including fungus gnats. Summit® Year-Round® Spray Oil is OMRI Listed® by the Organic Materials Review Institute and approved for use in certified organic production, and it’s perfect for indoor use.
Unlike many other pesticides that kill insects with toxic chemicals, Summit® Year-Round® Spray Oil literally smothers insects to death. The oil spray blocks an insect’s breathing holes (called spiracles), causing insects to die from asphyxiation.
Summit® Year-Round® Spray Oil can be used any time during the year because it won’t harm plant buds, shoots or leaves. This lightweight oil has no odor, and it will effectively control pests on even sensitive plants such as tropical houseplants, roses, impatiens, citrus trees, and ferns. Summit® Year-Round® Spray Oil kills fungus gnats plus a wide variety of insect pests including aphids, whiteflies, spider mites, mealybugs, scale, thrips, lace bugs and more.
Because of its low toxicity, organic Summit® Year-Round® Spray Oil can be used on garden plants and fruit trees right up to the day of harvest. Unlike chemical pesticides which can become less effective after repeated use, there is no known build-up of insect resistance to horticultural oil sprays.
Mosquito Bits® and Summit® Year-Round® Spray Oil are made by Summit Responsible Solutions®, which also makes Mosquito Dunks®. Mosquito Bits® are available in an eight-ounce shaker bottle and a large 30-ounce package. Summit® Year-Round® Spray Oil concentrate is available in one pint and one quart bottles, and a handy one-quart ready-to-use spray bottle is also available.
Mosquito Bits® and Summit® Year-Round® Spray Oil are available at home centers, hardware stores, garden centers and at www.SummitResponsibleSolutions.com.
Mosquito Bits, Summit Year-Round Spray Oil, Mosquito Dunks, Summit Responsible Solutions and “Kills Mosquitoes Before They’re Old Enough to Bite” are registered trademarks of Summit Chemical Company.