Fungus Gnats And Spinosad

[Savage Henry]

Hi all,

I've been dealing with fungus gnats in my coco DTW system for a bit now. I've used gnatrol at the maximum (7g/gal) rate 3 times now, 5 days apart and the problem still persists, in fact I'm catching even more fliers than before I started the treatment two weeks ago. I believe this is due to the coco being constantly moist and the 15% daily irrigation runoff.

Just bleached my drain trays and gutter two days ago.

I haven't allowed the pots of coir to dry out as it will cause the fertilizer to crystallize and cause an unwanted ec spike.

So as I was searching I found this article (https://manicbotanix.com/fungus-gnats-in-coco-coir/) from the manic botanix blog, a source I feel is reputable. He suggests performing a drench with a 75ppm spinosad solution at lights out and then flushing an hour before lights on.

From searching around here it appears that @Seamaiden has had success with this technique, if she can elaborate on it I sure would appreciate it.

I'm thinking the volume of the Drench for a 2gal pot should be somewhere between 2-4cups, applied with a watering can to ensure full coverage.

Does anyone else care to share their experiences with this technique?

 

[MeJuana]

Seamaiden gives good advice. If you're not in flower hang Hot Shot No Pest Strips that will knock the fliers down. I hang 3 of them that cover 900 or 1500 sqft in a tiny veg room. First time I started doing it spiders and stuff were dead near the entrance, bugs on the floor here/there and gnats everywhere.

Sometimes I keep everything in soil in one veg room then I clone all my strains into the other veg room, treat the clones+clone water with low dose hydrogen peroxide at first and hang those strips. That is my only go to move to for sure get rid of them 100%

 

[ken dog]

Sorry @Savage Henry ... it worked for me... And I did the same thing you did but I was in a soilless mixture (Promix HP and perlite).
And I made sure to use RO water.


I hope that plan B works.

 

[ken dog]

For what it is worth, Gnatrol only destroys the larva... Which is designed to interrupt the life cycle.

It is important to control the gnats so that they don't lay more eggs because that to start the cycle over again, and it takes about 3 days for the larvae to hatch...and another 10-14 days to develop and emerge... and 5 days to lay eggs and die.

http://ipm.ucanr.edu/PMG/PESTNOTES/pn7448.html#LIFE

Fair use excerpt:

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. A generation of fungus gnats (from female to female) can be produced in about 17 days depending upon temperature. The warmer it is, the faster they will develop and the more generations will be produced in a year

 

[HugzAndNuggz]

i know i did a soil drench with captain jacks once and it fried my sour power and wifi... took about 4 months for them to come out of it and start growing nice growth out of it to take clones and start over with them just glad i got to save them(just wanted to edit and say my sour power though has never been the same at the nodes they will almost graft the new shoots with the stem about 1/4-1/2 inch up then throw out twisted wierd shoots then start growing like normal) ... i did 1 oz a gallon drenched maybe i was to strong i know the foliar application is 2 oz a gallon and that what i have sprayed with for a preventative.. i know it kills the crap out of thrips

 

[Seamaiden]

So as I was searching I found this article (https://manicbotanix.com/fungus-gnats-in-coco-coir/) from the manic botanix blog, a source I feel is reputable. He suggests performing a drench with a 75ppm spinosad solution at lights out and then flushing an hour before lights on.

From searching around here it appears that @Seamaiden has had success with this technique, if she can elaborate on it I sure would appreciate it.

I'm thinking the volume of the Drench for a 2gal pot should be somewhere between 2-4cups, applied with a watering can to ensure full coverage.

Does anyone else care to share their experiences with this technique?

I didn't flush after the application. I just made sure that every watering had an appropriate dose of Spinosad in it (label directions, IIRC it's something like 1oz/gal for soil drench). Never caused any problems that I could observe, but I had to keep applying (and bleaching my drains!) to get the problem resolved. If I stop doing any one of those things, the FGs are back.

 

[GrowGod]

Hi all,

I've been dealing with fungus gnats in my coco DTW system for a bit now. I've used gnatrol at the maximum (7g/gal) rate 3 times now, 5 days apart and the problem still persists, in fact I'm catching even more fliers than before I started the treatment two weeks ago. I believe this is due to the coco being constantly moist and the 15% daily irrigation runoff.

Just bleached my drain trays and gutter two days ago.

I haven't allowed the pots of coir to dry out as it will cause the fertilizer to crystallize and cause an unwanted ec spike.

So as I was searching I found this article (https://manicbotanix.com/fungus-gnats-in-coco-coir/) from the manic botanix blog, a source I feel is reputable. He suggests performing a drench with a 75ppm spinosad solution at lights out and then flushing an hour before lights on.

From searching around here it appears that @Seamaiden has had success with this technique, if she can elaborate on it I sure would appreciate it.

I'm thinking the volume of the Drench for a 2gal pot should be somewhere between 2-4cups, applied with a watering can to ensure full coverage.

Does anyone else care to share their experiences with this technique?

Never used that technique but a good way to deal with them is nematodes. You can get 15 million for under 20 bucks on amazon or pay more at the g store:D
Also get a couple pyrethrum bombs and a can of spray for the flyers and last put a sticky card on each plant. You will fuck them up.

 

[DemonTrich]

Promis is excellent as well. But IS systemic, not for use after week 3 in flower, week 4 max. I use 3ml/gal for clones, 10ml/gal when up potting to 5gal pots, then once more at flip if needed at 15ml/gal.

 

[Savage Henry]

If you're not in flower

Unfortunately one of the rooms is about 4 weeks in, the other two are in veg still.

And I made sure to use RO water.

Looks like this is one of the ways I fucked up. I mixed the gnatrol into my Rez (which already had fertilizer in it) and then ran it through my drippers for a day. Maybe if I only run the drippers for half of the day and then apply the gnatrol mixed with ro with a watering can, giving the girls a good soak, then resume normal fertigation the next day it will be more effective.

i know i did a soil drench with captain jacks once and it fried my sour power and wifi...

Sorry to hear that, I did that with pyrethrin once. I'm planning to use the Monterey spinosad but same difference. I'll for sure test the mix/technique on a couple disposable veg plants before hitting everything.

I didn't flush after the application. I just made sure that every watering had an appropriate dose of Spinosad in it (label directions, IIRC it's something like 1oz/gal for soil drench). Never caused any problems that I could observe, but I had to keep applying (and bleaching my drains!) to get the problem resolved. If I stop doing any one of those things, the FGs are back.

Looks like i should plan on bleaching my drain trays, gutter, etc. on the same day as applying the spino for maximum efficacy.

Never used that technique but a good way to deal with them is nematodes. You can get 15 million for under 20 bucks on amazon or pay more at the g store:D
Also get a couple pyrethrum bombs and a can of spray for the flyers and last put a sticky card on each plant. You will fuck them up.

Nematodes were the first solution I tried. Applied them once about 3-4 days before the initial gnatrol application. They definitely seemed to slow down how many gnats were appearing daily on my sticky cards. Should have used them twice, i suppose.

Promis is excellent as well. But IS systemic, not for use after week 3 in flower, week 4 max. I use 3ml/gal for clones, 10ml/gal when up potting to 5gal pots, then once more at flip if needed at 15ml/gal.

I used promis almost a year ago to knock out some root aphids, didn't see any fungus gnats for a good while after that. I keep imid on the shelf, but only use it when in dire straits. Just a heads up, merit 75 has the same active ingredient as promis (imidacloprid) but is far more concentrated and way cheaper. A couple ounce jar is like $35, I did the math a while back and it's the equivalent of 60 bottles of promis (or bayer fruit and vegetable, same exact thing).


Anyway, thanks for the responses everyone. I'm going to jot down a firm plan at some point and will share my attack strategy when it comes together. Will probably be a combination of a more tactfully applied gnatrol then spinosad if it doesn't maim the test plants. I'll try and work some h. Miles predator mites in there too, but more for longevity, they take a couple weeks of repeated applications to gain the upper hand, ime.

I'll add this:
Spinosad appears to be a bioinsecticide, bacterially based kind of like bti (gnatrol). I don't foresee it causing problems but i definitely don't want to fry these broads midway through flower.

Edit: probably worth noting that the property in on is lousy with gnats, I'm talking swarms In the backyard a good 5 months of the year. Thinking I should just hit the whole place with microbe lift in a hose sprayer once a week. My rooms are sealed and filtered pretty good but the pest pressure is high.

 

[Savage Henry]

Here's something interesting i found, check out the graphs in this whitepaper on fungus gnat control of pointsettas grown in coir:

Apparently laying sticky traps horizontally over the pots as opposed to hanging them from a lower branch is far more effective.

A large release of h. Miles appears to be more effective than any of the tested pesticides.

Nematodes are most effective when applied weekly, 3 weeks in a row.

 

[stonestacker]

I had to use a Azamax drench in rock wool to solve my fg problum years ago. nothing else seemed to work for me.

Good luck with the fg war.

 

[Homesteader]

Microbelift BMC for birdbaths works for a decent price.

 

[DemonTrich]

Microbelift BMC for birdbaths works for a decent price.

Thats just BTI mosquito dunks, no?

 

[Homesteader]

No concentrated drops at a much cheaper price.

 

[GrowGod]

If it's really that big of a deal go to hind depot and get bug b gone, that shit will fuck those little bastards up :cool:

 

[Savage Henry]

If it's really that big of a deal go to hind depot and get bug b gone, that shit will fuck those

Shit, homie, if it was that big a deal I'd just drench everything in imid, but I keep that on hold in case of root aphids :puke2:

I ended up ordering 2x 25k tubes of h. Miles. They worked for me before so no sense in reinventing the wheel I suppose. I'll just put about 1k per pot in the flower room and use the rest in veg, probably follow up with the same in a week or two and be done with it. They're persistent and I've seen them crawl into and populate untreated pots (though I wouldn't depend on this).

While I wait for them I'll keep plugging away with the gnatrol, albeit in a more tactful fashion. That along with the weekly biowar tea (they got some last night) and I should be good. Will lay out some fresh sticky traps as well maybe 3 days after I introduce the predators to gauge their efficacy.

Thanks all.

 

[Savage Henry]

Bugs are here!

Gonna apply em when the lights come on, I'll lay out some fresh stick traps in a few days to gauge efficacy and catch the remaining adults.

 

[Trixxi]

Here's something interesting i found, check out the graphs in this whitepaper on fungus gnat control of pointsettas grown in coir:

Apparently laying sticky traps horizontally over the pots as opposed to hanging them from a lower branch is far more effective.

A large release of h. Miles appears to be more effective than any of the tested pesticides.

Nematodes are most effective when applied weekly, 3 weeks in a row.

Have you tried diatomaceous earth outside in your yard?? Probobly most cost effective for the outside ones you have. spread it all over the ground where they are flying and keep it dry. Should work a few days then reapply. I'm battling a similar problem here but it's gnats and root aphids in soil on geopots

 

[Trixxi]

If you can get to a farm store like Wilco or a pet supply place usually has big Five pound bag for about ten dollars

 

[Trixxi]

View attachment 617528 Bugs are here!

Gonna apply em when the lights come on, I'll lay out some fresh stick traps in a few days to gauge efficacy and catch the remaining adults.

You can leave the

Shit, homie, if it was that big a deal I'd just drench everything in imid, but I keep that on hold in case of root aphids :puke2:

I ended up ordering 2x 25k tubes of h. Miles. They worked for me before so no sense in reinventing the wheel I suppose. I'll just put about 1k per pot in the flower room and use the rest in veg, probably follow up with the same in a week or two and be done with it. They're persistent and I've seen them crawl into and populate untreated pots (though I wouldn't depend on this).

While I wait for them I'll keep plugging away with the gnatrol, albeit in a more tactful fashion. That along with the weekly biowar tea (they got some last night) and I should be good. Will lay out some fresh sticky traps as well maybe 3 days after I introduce the predators to gauge their efficacy.

Thanks all.

my question is the hyposaspis are ok to use with spinosad and nematodes?? Ordered hypos to pick up Wednesday but have root aphids I drenched all plants with spinosad. I don't want to poison the hypos