fungus gnats - next level assistance

[mrphilips]

i have a tiny fly problem in my house... and in my orchids.

i am 95% sure they are fungus gnats.
tiny black-ish flies, like fruit flies or gnats. i see them hovering around all my potted plants. i got them from a money-tree someone gave me as a present (thanks - you know who you are).

lesson one learned - quarantine your plants before letting them play with the others, now lots of them have it.

they seem to prefer the moss and bark-chip potted plants more than say the sandy aloes or even the "general" soil plants. specifically, they have honed in on my orchids.

i have tried to go natural - cinnamon sprinkled on top and watering them with chamomile tea - kill the fungus, starve the gnat. but... they persist. it has been three months and many doses of both, no luck.

problems i am having deciding on a solution:

a) the chemical alternatives are a bit confusing - not really sure which product i should get by name based on what i'm trying to kill and what i don't want to kill...

b) will this kill my orchids? what i have:
2 phals potted in bark,
1 phal in moss (i just haven't re-potted it after getting it)
1 paph in bark
1 phrag in moss
1 brassidium in moss (also to be re-potted in moss/bark)
1 encyclia (clinging to a stick - unaffected thus far)

any suggestions on a level-two approach?
should i go chemical?
what name-brand choice do i make?

[OCRC_Dir_China]

We have this problem in China; I will be honest, the chemicals in China little to no information come with the chemical to combat them. And for this reason I won’t use them; so we had to go to fly tape, we hang them around and cut 2-3 inch lengths and place them onto the surface of the infected plants pots. We have to change them monthly but it keeps them in good check, we also use a hand held electronic bug zapper, which resembles a tennis racket.

[Leafmite]

I grow some plants that need to always stay wet and must be fertilized with organic fertilizer. Fungus gnats love this scenario. I have found the butterwort (a carnivorous plant) to be the solution to my problem.

[Cactuseed]

I always have a f gnat flying around but he is likely to die. You are correct in that they come in on outside soil. I have a 3 prong approach. 1 - I kill the larvae in the soil by watering with rainwater from my barrel that has a mosquito dunk in it. This bacteria will kill the fungus gnat larvae in the soil when you water it. I hear you can also sprinkle on the surface of the soil. mosquito dunk
2- get some tangle trap paste and paint it on a yellow solo cup. The adults fly to it and can't get up and die
3 - grow some carnivorous plants. They love similar conditions to orchids and use the buggers for fertilizer. Cape sundew will have the buggers stuck all over it.

[ALToronto]

In addition to the above remedies, sulphur spray can keep them in check. You can buy powdered sulphur (a fungicide) and mix your own spray, or buy the spray pre-mixed. Shake vigorously before using. It's a non-toxic remedy.

[mrphilips]

i brought a wee sundew home from muskoka last summer - they grow along the river's edge at my parent's cottage. this variety is beautiful, but tiny and needs intense humidty - couldn't keep it alive after the fall either. maybe it's an annual. i will look into a carnivorous option.

will also look into the other suggestions - i water with rain water (melted snow right now) and could try to add something to it, or use any of the other suggested products and will try the sticky traps

thanks for the advice!

[Paul]

Originally Posted by mrphilips

i brought a wee sundew home from muskoka last summer - they grow along the river's edge at my parent's cottage. this variety is beautiful, but tiny and needs intense humidty - couldn't keep it alive after the fall either. maybe it's an annual.

Unlikely that humidity was the issue. I have tropical varieties and they handle my 30% or less winter RH just fine. Most dews require:

• a lot of sun or dew production stops
• low mineral water (so use rain or RO or distilled)
• moist (not necessarily wet) soil
• media that contains no fertilizer

It is possible that it was an annual ... quite a few of the northern species are. Even it if wasn't, a dormancy would have been necessary for any of the far north varieties.



Mosquito dunks work quite well though they are not an instant fix -- generally takes a week or two. You can find them at any home improvement store like Lowes or HomeDepot.

• Take a 1/4 of a dunk "donut" and put it in a gallon (3.8L)jug, fill with water, and let sit overnight or longer.
• Water your plants with the water but leave the dunk chunk in the jug and refill with water. (You can reuse it many times over until it disintegrates.)

[mrphilips]

Originally Posted by Paul

Mosquito dunks work quite well though they are not an instant fix -- generally takes a week or two. You can find them at any home improvement store like Lowes or HomeDepot.

• Take a 1/4 of a dunk "donut" and put it in a gallon (3.8L)jug, fill with water, and let sit overnight or longer.
• Water your plants with the water but leave the dunk chunk in the jug and refill with water. (You can reuse it many times over until it disintegrates.)

Paul, my dunks arrived today - couldn't find them in stock anywhere to i had to order them. i will do as you suggest!

i have a few questions:

1. should this be safe on all my orchids? i have a few random (unknown heritage) phals, a paph rothschildianum, a brassidium dr john, an enc bractenscens (not an issue - mounted and no gnats on the stick), but i also have a phrag pearcei that is tempermental... it seems to like to be constantly wet and i even sit it on a dish of water refilling twice a week. it's in spag which i change twice a year, and it gets black tips if i ever fertilize it. i also only ever water it with rain water. it has the "bug", but will the dunk harm it?
2. should this be ok for the other non-orchid plants?

[Nexogen]

Search for "mosquito dunks" @ Home Depot

It’s 0K for orchids and the other non-orchid plants.

[Subrosa]

Your Sundew was likely just going dormant. Temperate species require a winter dormancy period. Put them in an unheated garage or basement until spring and they regrow. A tropical species like a capensis would probably be better suited for your situation.