Bananas.org - View Single Post - Question about Fungus Gnats: Do they really eat the inside of seeds?

inkcube · 02-17-2008, 01:31 PM

fungus gnats reproduce in moist, shaded areas in decaying organic matter such as leaf litter, rotting bark, etc. their life cycle is roughly 4 weeks, with continuous reproduction in homes or greenhouses where warm temperatures are maintained. broods will overlap, with all life stages present during the breeding season. generally the larvae not only feed on fungi and decaying organic matter, but on living plant tissue, particularly root hairs and small feeder roots - i have never seen any documentation on the larvae consuming seeds but that does not mean they won't, just that they are more likely to eat soft tissue.

symptoms on roots show up as brown scars, underground parts of the stem may be injured and root hairs eaten off. damage occurs most often in greenhouses or plant beds.

adults live about 7 to 10 days and deposit eggs on the moist soil surface or in soil cracks. females can anywhere from 100 to 300 eggs in batches of 2-30 in decaying organic matter. the eggs hatch in 4 to 6 days; larvae then feed for 12 to 14 days with a pupal stage of about 5 to 6 days.

some preventive measures:
overwatering, water leaks and poor drainage may result in buildup of fungus gnats. always allowing the soil to dry as much as possible, without injury to the plants, is an effective method of killing many maggots. houseplants taken outside during warm weather may become infested with insects before being brought back indoors, inspect carefully and discard if heavily infested or unable to save. remove all old plant material and debris in and around the home. practice good sanitation. bug zappers will attract and kill many adults at night.

treatment:
yellow sticky cards (traps) for adult fungus gnat detection - fungus gnats are highly attracted to yellow. just place traps just above the plants at a frequency of one every 500 to 1,000 square feet. check traps 2 to 3 times each week and replace when covered with insects. sprays are also effective, fungus gnats are killed easily with pyrethrins spray or aerosols labelled for "gnats" or "flying insects."

02-17-2008, 01:31 PM	#5 (permalink)
inkcube retired GMO maestro Location: traveling the world Join Date: Nov 2007 Posts: 121 BananaBucks : 4,278 Feedback: 0 / 0% Said "Thanks" 6 Times Was Thanked 96 Times in 43 Posts Said "Welcome to Bananas" 0 Times	Re: Question about Fungus Gnats: Do they really eat the inside of seeds? fungus gnats reproduce in moist, shaded areas in decaying organic matter such as leaf litter, rotting bark, etc. their life cycle is roughly 4 weeks, with continuous reproduction in homes or greenhouses where warm temperatures are maintained. broods will overlap, with all life stages present during the breeding season. generally the larvae not only feed on fungi and decaying organic matter, but on living plant tissue, particularly root hairs and small feeder roots - i have never seen any documentation on the larvae consuming seeds but that does not mean they won't, just that they are more likely to eat soft tissue. symptoms on roots show up as brown scars, underground parts of the stem may be injured and root hairs eaten off. damage occurs most often in greenhouses or plant beds. adults live about 7 to 10 days and deposit eggs on the moist soil surface or in soil cracks. females can anywhere from 100 to 300 eggs in batches of 2-30 in decaying organic matter. the eggs hatch in 4 to 6 days; larvae then feed for 12 to 14 days with a pupal stage of about 5 to 6 days. some preventive measures: overwatering, water leaks and poor drainage may result in buildup of fungus gnats. always allowing the soil to dry as much as possible, without injury to the plants, is an effective method of killing many maggots. houseplants taken outside during warm weather may become infested with insects before being brought back indoors, inspect carefully and discard if heavily infested or unable to save. remove all old plant material and debris in and around the home. practice good sanitation. bug zappers will attract and kill many adults at night. treatment: yellow sticky cards (traps) for adult fungus gnat detection - fungus gnats are highly attracted to yellow. just place traps just above the plants at a frequency of one every 500 to 1,000 square feet. check traps 2 to 3 times each week and replace when covered with insects. sprays are also effective, fungus gnats are killed easily with pyrethrins spray or aerosols labelled for "gnats" or "flying insects."