Get Rid of Fungus Gnats For Good Using Mosquito Dunks

[LifeOblivious]

OK... Dunks in Hydro have caused a huge problem for me. I am posting this in hopes that someone can stop my plants from dying and so others can avoid killing their plants! I started a thread here in the infirmary "PH Out Of Control!!! Please help!" nut this is topic spacific so here goes:

My buddy has some mothers in dwc which were started in a closet for the 1st 3 months bad ventalation, heat, root rot.. however the plants looked great. about a week ago they were moved into a proper room with proper vent/temp. Then some fungus gnats were discovered and he decided to treat with musquito dunks. The dunks were crushed in a bag and water run through it kinda like an extract, then that was poured over the net pot of 3 plants. About a day or two later he picked up some sm-90 and put that in the res. He uses bc nutes with hygrozyme, so that was also in the mix. Now, the PH goes from 5.5 to 6.7 in three hours! even efter flushing, soaking over and over... Please Help!!! Plants are dying!

Here's an update, There is now an ebb & grow system (no plants in yet thank god) that is affected by the same ph rising as the buckets... The ebb res was dosed w/ a crushed up dunk while there was Aquaflakes Nutes and Hygrozyme in the mix. So I don't think the sm-90 was the culprit. I'm sure now that it is the dunk or dunk+hygrozyme that is the cause. Is anyone aware of this being an issue?
The buckets and the ebb res were fine and stable, buckets for 3 months and the ebb res for a week before this prob. All rocks were rinsed and ph'ed. This is so strange! I have replaced h2O with plain ph'ed h2O, h2O w/ nutes, h2O w/nutes & hygrozyme/h2O2... Nothing works, and yes I have flushed/soaked the net pots plenty.

Plants R dying as we speak... please help!

 

[LolaGal]

OK... Dunks in Hydro have caused a huge problem for me. I am posting this in hopes that someone can stop my plants from dying and so others can avoid killing their plants! I started a thread here in the infirmary "PH Out Of Control!!! Please help!" nut this is topic spacific so here goes:

My buddy has some mothers in dwc which were started in a closet for the 1st 3 months bad ventalation, heat, root rot.. however the plants looked great. about a week ago they were moved into a proper room with proper vent/temp. Then some fungus gnats were discovered and he decided to treat with musquito dunks. The dunks were crushed in a bag and water run through it kinda like an extract, then that was poured over the net pot of 3 plants. About a day or two later he picked up some sm-90 and put that in the res. He uses bc nutes with hygrozyme, so that was also in the mix. Now, the PH goes from 5.5 to 6.7 in three hours! even efter flushing, soaking over and over... Please Help!!! Plants are dying!

Here's an update, There is now an ebb & grow system (no plants in yet thank god) that is affected by the same ph rising as the buckets... The ebb res was dosed w/ a crushed up dunk while there was Aquaflakes Nutes and Hygrozyme in the mix. So I don't think the sm-90 was the culprit. I'm sure now that it is the dunk or dunk+hygrozyme that is the cause. Is anyone aware of this being an issue?
The buckets and the ebb res were fine and stable, buckets for 3 months and the ebb res for a week before this prob. All rocks were rinsed and ph'ed. This is so strange! I have replaced h2O with plain ph'ed h2O, h2O w/ nutes, h2O w/nutes & hygrozyme/h2O2... Nothing works, and yes I have flushed/soaked the net pots plenty.

Plants R dying as we speak... please help!

Well how many dunks did u crush up and put in there? I doubt that you needed more than 1/4 of one dunk. One dunk treats a whole durn pond or lake!!!!!!

since u removed the dunk, cleaned the medium and replaced the water and u are still having troubles, I don't know what your problem could be. I will go ask Sleepy to help you.

quit blaming the dunks, they are probably not the problem.

I have never used them in hydro, others have and had no problems.

 

[LifeOblivious]

I used one whole dunks, crushed up in a 50 gal res for a 24 pot ebbngro. I guess that could have been too much, but I had read many other posts where ppl did the same with no adverse effects. I am about ready to ditch the rocks altogether as it seems that no matter how much I flush, the problem still remains. The thought of washing all those rocks again is not very appealing. I do have about 5 bags of coco croutons though. Any experience with those? Not sure if they would be good in an ebbngro being flooded for that long. All I can say is that I am sure glad that this happened before transplanting! (as far as the ebbngro goes!) The dwc buckets are still suffering though

 

[Centrum]

I have AN ASS LOAD Of coco.

Found the larvae today was so disgusting!

So can i buy some dunks and throw them in my resivoirs use 2 30 gal res a week atleast easy.

Or would buying Mosquito Bits 30 Oz and spreading it over the coco work.
Or crushing the dunks and spreading them over the soil.

I have this bayer advanced stuff i bought with Imidacloprid i will be using this stuff once a week, and then grabbing some sticky traps.

I also have a canister of Gnatrol i never opened.

I could also mix the bits and peices into my coco everytime i mix a table,
would that be the best prevention for the future ?

Hate these Sons of bitches, they wilted a 3 week old Dieselrella! BAM! Gone!


Sorry im so scattered and jumbled with alternatives.

So stick with the bayer Imidacloprid every week mixed into my feeding schedule?
Then add the gnatrol ? or Dunks or pellets?

 

[puff adder]

The Bayer stuff with Imidicloprid won't kill the fungus gnats, and be very careful. It is systemic, and should not be used in flower. I used it in early veg for root aphids.

Imid is not to be misused. Usually one to 2 applications is all that's necessary to kill off the aphids. I don't think using it once a week would be good.

Read the thread about root aphids to learn more about Imid.

I use the dunks, they seem to maybe keep my fungus gnats in check, but they're not working completely. I'm going to try Azamax.

 

[LolaGal]

Gnatrol is just an expensive version of the dunk. same thing inside the bottle.

Ya'll will have to report back on your experiencces in hydro, coco, and what not. I want to hear how ya'll are doing.

Me, I am in soil. So can't help with coco.

Ya'll having problems, there are mentors on the site to help ya'll with grow questions.

I am not sure who they are right now. Sleepy a member here is who I would ask if I had trouble with hydro, maybe Benji will help.

good luck.

 

[Centrum]

I Just ordered 40 dunks !! I will let you know how it works!

I found this on the web Co State University article.
It says the Imid will kill the larvae.

Fungus Gnats as Houseplant and Indoor Pests
by W.S. Cransaw and R. A. Cloyd 1 (4/09)
Quick Facts...
Fungus gnats are small, delicate bodied flies that commonly develop in the growing medium of houseplants.
Larvae of fungus gnats feed on algae, fungi and plant roots in growing medium. Adults do not bite or feed.
Fungus gnats can be controlled by allowing the growing medium to dry between watering.
Some insecticides and biological control agents can be used to control fungus gnat larvae in growing media.

Figure 1: Fungas gnat adult.

Fungus gnats (Bradysia species) – also known as dark-winged fungus gnats, are small, mosquito-like insects often found in homes and offices, usually in the vicinity of houseplants. They are considered a nuisance when present in noticeable numbers, but the adults are harmless insects that do not bite. Fungus gnat larvae develop in the growing medium of houseplants and are considered minor pests of houseplants.

Adults are 1/8 inch long, delicate, black flies with long legs and antennae. There is a distinct “Y-shaped” pattern on the forewings. The larvae are wormlike and translucent, with a black head capsule, and live in the gorwing medium of houseplants.

Life History and Habits
Fungus gnat larvae usually are located in the top 2 to 3 inches of the growing medium, depending on moisture level. They primarily feed on fungi, algae and decaying plant matter. However, the larvae will feed on plant roots and leaves resting on the growing medium surface. Larvae develop rapidly and are fully grown in two to three weeks. They then pupate in or on the growing medium.


Figure 2: Fungus gnat life cycle.

Adults emerge about one week later. Fungus gnat adults are weak fliers, typically flying in short, erratic patterns. In homes, they usually are seen in the near vicinity of an infested houseplant. However, adult flies may disperse short distances and often accumulate around window frames.

During their seven to 10-day life span, females may lay up to 200 eggs into the cracks and crevices of growing media. Moist-growing media containing high amounts of peat moss are particularly attractive to adult females. At typical room temperatures (65 F to 75 F) the life cycle (egg to adult) may be completed in three to four weeks (Figure 1) with continuous reproduction occurring yearround on indoor plants. Fungus gnat adults do not bite but may drink water residing on plant leaves and/or on the surface of growing media.

Nuisance problems with fungus gnat adults tend to be most noticeable during late fall and winter. There are several factors that may account for this seasonal peak. First, houseplants maintained outdoors during summer will commonly be colonized by fungus gnats and when these plants are brought indoors, populations may subsequently increase in response to the warmer temperatures encountered in homes. Second, fungus gnats may be more noticeable during cooler weather, when people spend more time indoors, thus increasing the likelihood that fungus gnat populations will be highly noticed.

However, the primary reason why fungus gnats are abundant in homes is related to changes in moisture levels associated with the growing media of houseplants. Fungus gnat adults are highly attracted to moist-growing media. Furthermore, as the growing medium ages or degrades it tends to retain more moisture, which will also attract fungus gnat adults. In addition, decreased day length and cooler temperatures slow plant growth and water usage. If watering practices are not altered, particularly during fall and winter, the growing medium will remain moist, which improves conditions for fungus gnat development.

Management
The most important strategy to minimize fungus gnat problems associated with houseplants is to allow the growing medium to dry between watering, especially the top 1 to 2 inches. The dry-growing medium will decrease survival of any eggs laid and/or larvae that hatch from the eggs as well as reduce the attractiveness of the growing medium to egg-laying adult females. In addition, it is recommended to re-pot every so often, particularly when the growing medium has “broken down” and is retaining too much moisture. Furthermore, be sure to remove any containers with an abundance of decaying plant matter such as decayed bulbs and roots, which provide an excellent food source for fungus gnat larvae.


Figure 3: Fungus gnat on sticky card.

Insecticides may be necessary if fungus gnat problems persist several weeks after watering practices have been adjusted. Direct treatments at the adults or larvae; however, different approaches are used against each life stage. Typically, when fungus gnat populations are excessive, repeat applications are required to deal with adults. Apply insecticides to the growing medium surface since this where new adults will emerge.

The most effective treatments are those that are persistent; killing adults for up to three days. A number of pyrethroid-based insecticides, with extended persistence, are available for use on houseplants including those containing the following active ingredients: bifenthrin, cyfluthrin, permethrin, and lambdacyhalothrin. Short-persisting contact insecticides such as those containing pyrethrins, soaps, oils, and neem, do not provide sufficient long-term control of fungus gnat adults and require repeat applications at short intervals (couple of days) to exhibit effects.


Figure 4: Fungus gnat larvae on potato slice.

The larvae in the growing medium will not be directly affected by any insecticides applied to kill adults. An alternative approach to deal with fungus gnat adults, particularly when populations are abundant, is to strategically place yellow sticky cards (sold as Gnat Stix) underneath the plant canopy or on the edge of containers. The adults are attracted to yellow and will be captured on the sticky cards. This may be helpful in mass-trapping adult females, thus reducing the number of larvae in the next generation.

Larvae may be killed by the microbial insecticide Bacillus thuringiensissubsp. israelensis (Bti) when applied as a drench to the growing medium. However, formulations of Bti sold for fungus gnat control generally are unavailable through retail outlets. The Bti product marketed as Gnatrol is used in commercial greenhouses and large interior environments.

The systemic insecticide imidacloprid will also kill fungus gnat larvae when applied to the growing medium. This active ingredient is available in a number of houseplant insecticide formulations as granules, slow-release “spikes”, and in combination sprays with a pyrethroid-based insecticide.

A biological control option for control of fungus gnat larvae is applications of certain insect parasitic (or entomopathogenic) nematodes as a drench to the growing medium. Insect parasitic nematodes are microscopic roundworms that enter fungus gnat larvae through natural openings such as the mouth, anus and breathing pores. The nematodes emit a bacterium that digests the internal contents of the larvae. Fungus gnat larvae die within three to four days. The nematode species Steinernema feltiae is particularly effective against fungus gnat larvae.

An effective means of detecting the presence of fungus gnat larvae is to insert 1/4 inch slices or wedges of potato into the growing medium. Larvae will migrate to the potato and start feeding within a few days. The potato slices should be turned over to look for larvae present on the underside.

1W. Cranshaw, Colorado State University Extension entomology specialist and professor, bioagricultural sciences and pest management; R. A. Cloyd, Kansas State University associate professor and Extension ornamental entomology/ integrated pest management, entomology. 3/03. Revised 4/09.

 

[perennial]

I got a bad case of fungus gnats at day 50 of flower in an organic soil grow. One day all my buds had green frosty trim and a few days later almost all the vegetative leaves were yellowing. I used the Bt dunks and it worked well with the gnats disappearing in a day or two and the damage appearing to be halted.

Now that I'm at 60 days of flowering the buds are OK but not really healthy looking. Trics are cloudy but I want some amber. I'm wondering whether to stick it out until amber trics or cut now while I still have basically healthy buds. That's the first question.

The second question is what to do with the yellow trim leaves that were previously frosted. I was planning to do cannabutter with them but now I don't know whether that is still OK. The trics seem to dry out and flatten when the leaf dies. Is it safe to make butter with yellow trim leaves?

 

[LolaGal]

Cut some buds now and wait a while till the rest get amber, cure, smoke, decide what u like best.

I have put yellow leaves in butter, no problems there. I am still alive and stoned.

 

[perennial]

Cut some buds now and wait a while till the rest get amber, cure, smoke, decide what u like best.

I have put yellow leaves in butter, no problems there. I am still alive and stoned.

I have been sampling bud and cutting some to hedge against further damage. The smoke is good but the buzz is a little racy. I'm looking for a little mellower buzz so I want some amber.

I wanted to hear that someone tried the yellowed leaves and lived to tell. Thanks. They had trics so some active ingredient must still be there.

The dunks are great, they saved four months of work for me.

 

[Cannaseur Kid]

I am using those dunks as we speak in coco and perlite with great success. crushed up in the medium and one in a tea bag in every reservoir. IT'S NOT THE DUNKS! Back off on your nutrients and take a close look at your nutes and test for any compatiability issues. Other than that the pests may be so well established in your rhizosphere that they are the cause of the alkalinity issue. i.e. biological waste. It will take a while to straighten out any bad problems. shitty.

 

[orangejuice]

been using crumbled dunks for a lil over a month now (when i first saw 1-2 gnats) and they have done zero to curb them in my coco. now i see 5-6 per pot at least when watering. made sure to treat every bit of coco new and old, got rid of any stagnate water, perlite layer to make the topsoil seem dry, and they just keep on coming. they have been driving me crazy and im about to jsut give up on getting rid of them, they don't seem to be doing much harm but it's seriously making me hate coco, never had a problem this bad in other mediums.

 

[mikessong]

about to try them in coco, hope they work...

oj, even if the dunks are working, it is still possible that a few gnats could come in when you enter/exit the room, right? i wouldn't rely on the dunks alone, especially for an active population, i would add sticky traps, and an aerosol pyrethrin spray (safer brand is good) if in veg/early flower. and also you can keep the top of the coco pretty dry, not just seem dry. sprinkle some on top very loosely and don't disturb it and for me it usually results in a very thin dry layer on top which helps somewhat to cut down on the critters. good luck.

 

[fat.labia]

These are a great tool and natural too!

 

[orangejuice]

i would add sticky traps

yah i bought some of those, they worked great for 1 thing and that's ripping leaves of my plants when i took them out for their daily watering killing adults... not so much, got maybe 2 per strip after a week.

don't want to use any spray chems as the girls are flowering and the gnats don't seem to really be causing any harm. checked the roots multiple times and they are fine too, "if it aint broke..."

the coco i got was dried compressed brick, not even wet bags and i'm positive the dry bricks are what was infested, so these are some resilient little fucks. gonna bomb and clean up the room after these girls are done, buy coco from the new shop i go to and if it is also infested then just going to move to a hydro setup as those generally are effortlessly pest free in my experience, as long as you yourself don't contaminate the room with dodgy clones or pull stuff in on your clothes/skin from outside.

 

[minds_I]

Hello all,

Just wrote a thread about my expeerience with Gnatrol....Great stuff...stops the fungus gnat lifecycle and they are gone.

Got mine on ebay cheap...24 bux delivered fast too.

minds_I

 

[LolaGal]

gnatrol and dunks is the same thing...

 

[benzo]

anyone use them in coco with positive results??

 

[Stuff]

Does anyone know if the Dunks mess the pH? Do they raise/lower the pH?

 

[reckon]

anyone use them in coco with positive results??

I am a soil grower, but I use coco to clone, and I got a bogglegum motherplant from a local grower and it had gnats

I read this thread, and bought some dunks, and crumbled some on every open soil, and coco surface I have.

been over 2 weeks now, and I still have a gnat infestation, and it seems to be getting worse

I just dr. doom fogged the shit out of the clone closet, and I'm going with more crumbled dunk on all exposed soil and coco surfaces.

but so far this is NOT WORKING!!!

I am going to build an isolation chamber so that I can put new strains in there for a few weeks to kill off any hitchhikers

I HATE GNATS!!!