Predatory Soil Mites For Fungus Gnats?

[Dankalicious]

http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7448.html

A lot of people who use what they call "living soil" have soil mites.
Those people claim they are beneficial and do not harm the plant.

I find them on and off and believe they either come from the worm castings or let themselves in.

Recently I started growing lettuce under T5s for personal use (I swear it's personal and for legitimate health reasons). Well this created a haven for gnats, and since I won't spray anything on my lettuce they are just going nuts. So I located an older mother plant who I knew had these soil mites living in the container, and took samples and spread them throughout my entire plant collection to see if they would keep the gnats down and possibly prevent aphids in the coming weeks.

Any thoughts on using these guys for pest control?

 

[Seamaiden]

Now that I've started using Spinosad as a root drench (and keeping ALL my drains clean and bleached) it's been more than a month since I've seen a fungus gnat.

Are these mites in your soil keeping the FG populations down? They're a real problem with seedlings, I can't tell you how many I've lost to the FGs, mature plants can handle the assault. If they work, I say fantastic, another tool in the arsenal and what makes it even better is it can be a sort of "set it and forget it" solution.

 

[SeaF0ur]

first...

fungus gnats:
have a mosquito shaped body
visible segment between thorax and abdomen
wings end at the end of insect
when landed, holds its wings flat on top of its back
the center wing vein has a Y at the wingtip

winged root aphids:
have a beetle shaped body
slightly "fat" looking with no segment between thorax and abdomen.
wings extend past the end of the insect
when landed, holds its wings at angles like a wasp
wing veins are all straight

either way, rove beetles and scimitarus mites are your friends...

 

[Dankalicious]

first...

fungus gnats:
have a mosquito shaped body
visible segment between thorax and abdomen
wings end at the end of insect
when landed, holds its wings flat on top of its back
the center wing vein has a Y at the wingtip

winged root aphids:
have a beetle shaped body
slightly "fat" looking with no segment between thorax and abdomen.
wings extend past the end of the insect
when landed, holds its wings at angles like a wasp
wing veins are all straight

either way, rove beetles and scimitarus mites are your friends...

Easiest way to tell an aphid is to get out a loops and look for the two spikes coming off the abdomen.

 

[stickyfing3rs]

Mosquito dunks/ mosquito bits. Works slick as shit

 

[Sunbaked]

1/4 inch layer of sand on top of soil smothers the larva and kills them . gnats are easy to get rid of in soil.

 

[Papa Indica]

Mosquito dunks/ mosquito bits. Works slick as shit

I use the Mosquito Bits.

 

[stickyfing3rs]

I use them in a rdwc system, tried and tried and tried to rid them shits. Contemplated tearing everything down and starting over after a deep clean. Then ran across the mosquito bits. I put 1/2 TSP in my 80 gallon system and slowly started to see less and less of them. 2 weeks and they were gone. Since then Ill just throw in 1/4 of one of the dunks. Haven't seen any since

 

[Papa Indica]

I use them in a rdwc system, tried and tried and tried to rid them shits. Contemplated tearing everything down and starting over after a deep clean. Then ran across the mosquito bits. I put 1/2 TSP in my 80 gallon system and slowly started to see less and less of them. 2 weeks and they were gone. Since then Ill just throw in 1/4 of one of the dunks. Haven't seen any since

I'm in soil, sprinkle some over the top of my pots and like you say, they slowly disappear. I actually sprayed a little Natria too to help get rid of the fliers quicker, only on my pots and floor though, not on my plants.

 

[Sunbaked]

sand

 

[Dankalicious]

Not trying to use any pesticides though. If I was going to use pesticides I'd just spray everything down with azamax. That would wipe them all out at once.

 

[Dankalicious]

Wouldn't a sand barrier prevent air exchange?

 

[GrowGod]

I Use nematodes and a spray or two with pyrethrum, no more floating larvea popping around when I water

 

[stickyfing3rs]

Not trying to use any pesticides though. If I was going to use pesticides I'd just spray everything down with azamax. That would wipe them all out at once.

Mosquito bits are a microbial insecticide. (BTI) same as one of the species in og biowar foliar pack.

 

[Seamaiden]

Wouldn't a sand barrier prevent air exchange?

No, it doesn't, but in my experience neither does it do shit for FGs.

The mosquito dunks are as described above, and Spinosad is another 'cide' derived from bacteria. I find it's very safely used as a root drench. And don't forget to bleach your drains! (and don't forget to wash the bleach out after 15-20mins, my plumber neighbor says.)

 

[Natural]

gnatrol is the best. dunks and spinosad didn't do anything to my gnats..although spinosad will devastate thrips

 

[Seamaiden]

Isn't it weird that Gnatrol didn't do shit for my FG problem, where Spinosad did, but it's the opposite for you? I find that so odd.

 

[Natural]

Isn't it weird that Gnatrol didn't do shit for my FG problem, where Spinosad did, but it's the opposite for you? I find that so odd.

yes it is quite odd. Had a recent bout with thrips..ended up using Conserve sc to rid them out of my garden. In doing so, the soil was more wet than I prefer. Exactly one week after the Spinosad treatment I was raking the pots and found a pretty decent population of fungus gnats. I was very nervous that they were aphids at first because I thought Spinosad would kill them as well. I didn't have but maybe one or 2 gnats in the sticky cards prior to this outbreak. So I spent a good time scoping what was exactly flying around in the pots. Sure enough fungus gnats. So I add 1/2 cup scoop per 5 gallons of RO and use as a drench also adding the BTI corn bits...no more fungus gnats. It may have something to do with the age or source of the gnatrol imho..but it always works for me and is now a part of my regular IPM

 

[Seamaiden]

And I have NEVER seen a thrip. Yet. Probably when I move back to SoCal I'll get to enjoy thrips. And whiteflies. And spider mites, oh my!

I got my Gnatrol from a seller on eBay, and I do believe it is suspect. But, I already had the Spinosad on hand and I have an avocado growing in my dining room and that has been the last holdout place for FGs. Between hitting it with the Spinosad and bleaching my drains, I've all but eliminated them inside.

 

[Natural]

They can be devastating to plants. Hitchhikers coming in on fall stock promix. I used Monterey and thought they were gone..only to have them come back..and sneakily I might add. Conserve SC will remain in my bag of tricks permanently..thank you Virgin Island Rum and science!!