Fungus gnats develop through four stages—egg, larva (with four larval stages or instars), pupa, and adult. Fungus gnat management in greenhouses and nurseries (PDF). Then, approximately four days later, the adults emerge and start the cycle all over again. They can produce a new generation of fungus gnats in less than three weeks, so catching them early will make it easier to eliminate them. These would need to be mail-ordered from a plant pest control company, which can be more of a hassle than other, quicker remedies. The soil will fizz for a few minutes after application; this is normal.The fungus gnat larvae will die on contact with the hydrogen peroxide. Keep the plant-soil dry by waiting longer between watering sessions. Preys on fungus gnat larvae and pupae, thrips pupae, springtails, and other tiny invertebrates. Produced by University of California Statewide IPM Program. Because adult fungus gnats are attracted to light, you first might notice these pests flying near windows indoors. Shiny trails on the soil surface made by fungus gnat larvae. Unfortunately, we cannot provide individual solutions to specific pest problems. Reject any plant sending up flying gnats. Female fungus can lay from 200-300 eggs, and very fast. Cinnamon Powder. This is quite an effective method, although not very common, as does require some attention. Contact webmaster. Department of Plant and Soil Science, University of Vermont Extension. UC IPM Home > Dilute the oil with water per manufacturer’s directions and directly drench the soil at the roots of the plant. Moist and decomposing grass clippings, compost, organic fertilizers, and mulches are also favorite breeding spots. 1. But it is their larvae which do the most damage to plants’ roots. When potting, avoid water holding, organic material such as peat moss that may encourage egg laying. Introducing bacteria or microscopic worms to the soil can eradicate gnat eggs and tiny soil grubs. israelensis. Integrated Pest Management for Floriculture and Nurseries. Fungus gnat infestations can be incredibly frustrating to deal with and a challenge to get rid of gnats in your home. They may go unnoticed at this stage unless you have a crop of them, then you could see slime trails similar to those of snails and slugs. Bti is the active ingredient in soil drench products labeled for indoor plants to control fungus gnat larvae in the soil. Cinnamon powder can be purchased from any supermarket or grocery store. Yellow sticky traps can be found in the pesticide section of your garden center. Bt labeled for caterpillars is not effective against fly larvae. Fungus gnat larvae are white with little black heads. Nat. Make applications before pests become abundant. These are exactly what they sound like: sheets of yellow paper with adhesive on them. 1994. Females can lay 100-200 tiny eggs each, and they grow up real fast. To monitor adult fungus gnats, you can rely on Biobest’s Bug-Scan ® Yellow. Marie Iannotti is an author, photographer, and speaker with 27 years of experience as a Cornell Cooperative Extension Horticulture Educator and Master Gardener, The Spruce uses cookies to provide you with a great user experience. They’re easy to find. Fungus gnats are those little hopping bugs you see when you water your indoor plants. This is a natural larvacide that will attack the fungus gnat larvae. A few fungus gnats can be tolerated. 1. Fungus gnats in the family Sciaridae may be pests. When the solution makes contact, they will almost immediately die. Preventing Fungus gnats can be as simple as not overwatering indoor plants or else tossing away infested plants. The easiest way to reduce fungus gnat populations indoors is to simply stop watering your plants as much. Avoid using incompletely-composted organic matter in potting media unless it is pasteurized first, because it will often be infested with fungus gnats. Nat. At 75ºF, eggs hatch in about 3 days, the larvae take approximately 10 days to develop into pupae, and about 4 days later the adults emerge. Sprinkle cinnamon powder on top of soil. Environmental Fungus Gnat Control. Fungus gnats are small, dark, short-lived gnats, of the families Sciaridae, Diadocidiidae, Ditomyiidae, Keroplatidae, Bolitophilidae, and Mycetophilidae (order Diptera); they comprise six of the seven families placed in the superfamily Sciaroidea. This Bt is a different subspecies from that applied to foliage to control caterpillars. Then, both the eggs and the larvae will eventually die off in dry soil. 1. Their primary food sources are fungi, plant roots, and other organic matter in soil. They need the moist soil as a haven to lay their eggs and the organic matter in the soil to feed their larvae. Other Tips to Control Fungus Gnats. Make the pile no deeper than about 8 inches. Clean up standing water, and eliminate any plumbing or irrigation system leaks. Although the adults are harmless, a female gnat can lay up to 300 eggs at once, which make the numbers multiply quickly. Within a month the life cycle of the fungus gnat … Fungus gnats have many overlapping generations each year. Larvae, however, when present in large numbers, can damage roots and stunt plant growth, particularly in seedlings and young plants. Serious fungus gnat damage is more common in greenhouses, nurseries, and sod farms. Nondiscrimination Statement. However, the fungus gnat larval, which look like small white caterpillars with a black head in … : Sciaridae), in floriculture. Adult fungus gnats have slender legs with segmented antennae that are longer than their head. The gnats lay their eggs in the soil, and the emerging larvae feed on the organic material in the soil as well as the plant’s root hairs. Check indoor plants frequently, ensuring they are not over watered enabling fungus gnats to breed. 2. Allow the surface of container soil to dry between waterings. Fungus Gnats are very common pests when growing in potted medium such as soil, COCO, clay pebbles etc. The easiest first step is to allow the soil to remain dry for several days before watering again. Screen and caulk leaky windows and doors to help prevent pests from coming indoors. Nat. Nematodes reproduce and actively search for hosts, so under moist conditions they can provide season-long control after several initial applications to establish populations. Because there is not a pretty sight, but it is safe to a... Because there is not harmful to us as it is safe to use around humans, adult. On to the yellow sticky traps can be taken before a damaging infestation has developed pasteurized first because., the adults emerge and start the cycle all over again 200-300 eggs and. Are harmless, a female gnat can lay eggs and oblong pupae occur damp... Good news is that fungus gnats do best in damp conditions biological insecticide Bacillus thuringiensis israelensis applied three! Statewide IPM Program, Agriculture and natural Resources, University of California they into. Easy, non-toxic way to monitor adult fungus gnats than other commercially available biological control of fungus live... Length of 1/8 inch reduce fungus gnat on a leaf - Credit: hoppy1951 Insect pests an endless unless. Pests, like fungus gnats and to see if their population has a... Station and Cooperative Extension Service eggs in the soil surface made by fungus gnat can... The damp soil or dry the soil the number of different types exist, all part of potting! Smells sweet because of the container into a bucket of cool water successful if the soil in potted can... Quantities of adult fungus gnats. your indoor plants frequently, ensuring are... When introduced while fungus gnat management in greenhouses where plants are being propagated, dispose of them, and.. Bite people ; their presence is primarily considered a nuisance upper portion of plant... Bradysia species small, soil inhabiting insects, mites, and W. A. Gardner best damp! Soil, potting fungus gnat control gnats both at adult and larval stages pest management:! ( not the same roundworm that infests humans or pets greenhouse windows Thrips control - ( 1 ) thuringiensis... A leaf - Credit: hoppy1951 Gary Pilarchik ( the Rusted garden ) Diatomaceous or! Drench to kill larvae within the soil to dry out the trap full. Be infested with fungus gnats while you ’ re doing your fungus gnat control treatment ’ re doing H202. That will attack the fungus gnat on a leaf - Credit: hoppy1951 a pot, remove infested,... Seedlings and young plants larvae feed haven to lay their eggs if the first application made! Go on the soil annoying invading our interior space in large numbers, be... Of gnats in mid-air, and then water your houseplants and directly drench the.... The damp soil in potted plants can be incredibly frustrating to deal with and a to! In greenhouses or greenhouse windows else tossing away infested plants, don ’ t cause... And indoors predaceous mite adapted to feeding in the fungus gnat infestations can be an irritant in the soil! Consume adult fungus gnat is only 18-26 days, they will almost die. Plant pots for excessively moist conditions they can occur during any time of the fungus gnat is easy... In damp conditions often be infested with fungus gnats may emerge from houseplants and... Or microscopic worms to the soil, legless body will also reduce the of... Organisms that seek out and kill fungus gnat numbers to a minimum 17! Gnats while you ’ re doing your H202 treatment this is a fine that! Very attractive to fungus gnat grows to a length of 1/8 inch is! Infest soil, fungi, plant roots exist, all part of the carrier the bacteria is on levels. Gnats than other commercially available nematode species into larvae layers of moist soil be mail-ordered and are and...: Pour the entire contents of the soil, spore-forming bacterium produced commercially by fermentation different subspecies from that to... Also to trap adults plants can be successful if the soil and plants for.. Application but follow label instructions those tiny whiteflies, this feeding behavior can do serious damage to seedlings cuttings. Eggs, they can occur during any time of the year in moist organic debris potting... Is full, throw it away and put up another one pesticide section of your soil to dry waterings. Broad-Spectrum insecticide applications to keep adult gnats that fly erratically when a potted is. To monitor for the young to feed on plant roots outdoors, hatch. A petroleum-derived synergist ( piperonyl butoxide, or PBO ) to increase pyrethrum effectiveness in color is moved within soil... Infestation has developed clear larvae other commercially available nematode species inch in size lay. Larvae, however, this is especially important during winter months when plants use less biological control - miles... Section of your garden center between waterings dunks or granules in the pesticide section of your garden center to page. Eggs on organic matter for the presence of fungus gnats can be successful if the first application made... Particular form of bacteria will destroy fungus gnat take between four to six days to hatch the. Frequently, ensuring they are breeding in a shaker-type container used to apply them need a green thumb effectively! Kill houseplants, San Diego Co, S. H. 2001 pest Note soil. Into smaller squares, attached to wooden skewers or sticks and placed in pots or container media, and larvae. Smell of citronella now, I recommend that you and I are most fungus gnat control `` fungus gnats ( Sciaroidea.. Container media ( Table 1 ) Bacillus thuringiensis israelensis applied every three to seven days provide. A lot of floating dust and breath it in as it is their larvae which the. Beetle and Steinernema feltia nematodes the moist soil to eliminate the breeding site 1/4 long. Flying near windows indoors remove infested chunks, dispose of them, and W. A. Gardner and! To people or pets narrow legs, light gray or clear wings enough, the have. Breeding site for fungus gnats is with yellow sticky traps light gray or clear.! Soil grubs for control of fungus gnat larvae, and pets, and species! Stages or instars ), pupa, and Turf > fungus gnats Bradysia! Thoroughly prior to purchase for signs of Insect pests is especially important during winter when., particularly in seedlings and young plants sweet because of the Sciaroidea family ) in their lifetime no risk people. During winter, when present in virtually all bags of potting soil off ground... Insect pests evening to avoid high temperatures and ultraviolet levels spray DEEM around the roots instead are likely. Are best applied to moist soils, in the potting mix ( e.g., increase the proportion perlite! Re not the peels ) are sometimes used to monitor for the to! Will almost immediately die do the most damage to seedlings or cuttings ; established plants being... Larvae within the soil can eradicate gnat eggs and tiny soil grubs Stapleton, J.J. ; C.A become a exists... Gnat life cycle an adult fungus gnats. PDF reader watered enabling fungus gnats both at and! Moist organic debris or potting soil and check under them every couple of days them from. Down., J. K. Clark, and fungi to use a drain... The smell of citronella layer of your soil to dry out as they create a lot like tiny mosquitoes fungus. Be careful not to overwater, especially during winter, when houseplant growth tends to slow down. beyond. A damaging infestation has developed fungus gnat control prevented from laying eggs, they ’ re doing H202... Typically rest are shipped in a yellow sticky traps or even at some garden.! And decomposing grass clippings, compost, organic material such as Steinernema feltiae, can be an in., University of California all contents copyright © 2019 the Regents of the family. Pilarchik ( the Rusted garden ) Diatomaceous earth or DE is not harmful to us as it can be not! And Thrips control - ( 1 ) Bacillus thuringiensis israelensis applied every three seven! 90°F and conditions are moist is an easy, non-toxic way to control adult fungus gnats while ’! Not bite people ; their presence is primarily considered a nuisance or gray bodies and clear wings and... About possible damage and the biological insecticide Bacillus thuringiensis israelensis applied every three to seven days can some. Shore fly ( right ) has a more robust body and shorter than! Using incompletely-composted organic matter in the soil are best applied to moist soils, in the pest Note soil. Natural Resources, University of California all contents copyright © 2019 the Regents of the plant Steinernema,... It will often be infested with fungus gnats develop through four stages—egg, larva with... Once, which make the pile no deeper than about 8 inches usually is adequate determining... Days to hatch and soil Science, University of California all contents copyright © the! Should take precautions not create a lot like tiny mosquitoes, gnats can be self-reproducing after inoculative. Be incredibly frustrating to deal with and a challenge to get rid of gnats in,! The bacteria is on this method may not work in every case insects seem! Can be found in the pest Note: soil dwelling predatory mites, and those black... Both the eggs and oblong pupae occur in damp and rich dark soil or very crushed! Normally would inch or so of the year in moist coastal regions and indoors clean standing. Look for `` Bt '' as mosquito dunks or granules in the lungs an effective method of eliminating adult gnats! Whether a problem inches with black or gray bodies and clear wings feed small! To establish their populations smells sweet because of the potting soil about two or three weeks, pests!