Death to Fungus Gnats!

[2cb]

Hi everybody!

For years, ever since a woman left scrap veggies around my home while I was on vacation, I've had fungus gnats - previously never having a problem for 25 years. And I have tried quite a few things:

1. drying the soil out (you can leave it bone dry for months, and those suckers will start hatching as soon as you water again).

2. watering with soapy water (worked fairly well, but only very temporarily, not enough to last until another watering).

3. Thyme/Oregano oil in the water (killed them temporarily, but killed the plants just as much as the gnats).

4. Hydrogen Peroxide in the water, 16oz of 3%/gallon (killed flies, but not so much the larvae).

5. rectangular plastic yellow fly poison slabs (not effective at all).

6. sticky fly paper (works well, but never kills the larvae).

7. drum roll please! THE BEST I DID WAS THIS:

4oz Isopropyl Alcohol per gallon of water! Probably close to 3% alcoholic beer. Yes, it sounds like a very bad idea, but actually, it didn't seem to harm the plants at all! I also covered the potting containers with Saran Wrap to keep the fumes in above the soil surface (no drainage holes also), and I believe this was important, as over the next several hours, the flies appears to get severely intoxicated, then dying, and then later, the larvae got to the surface, and under 100x microscope, I could watch their intestines in convulsions, and they were suffering bad! Then I placed lots of sticky fly paper on top of the Saran Wrap to catch any escapees. It's been 48 hours, and not a sign of any larvae or gnats!

By far, the most potent solution I have found. Just amazing. I highly recommend this, since these gnats seem to survive anything! My plants are 100% fine, and not a single sign of gnat or larvae life! Just AMAZING! Deader than doornails!

I will keep this thread up in my browser for the next few days, and report any change in this current status, but for now, I am just so shocked at how effective this was that I had to report it! Also, I never read about anyone doing this before.

 

[symbiote420]

Get you some Sea-90 or Bonide Thuricide and some yellow stickies, both of them kill fungus gnat larvae quickly and quite effectively!!

 

[Ranger]

neem meal and mosquito dunks work well for me.

 

[2cb]

In a Remote Location

In a Remote Location

Get you some Sea-90 or Bonide Thuricide and some yellow stickies, both of them kill fungus gnat larvae quickly and quite effectively!!

Thanks for the tip, but I live 100s of miles from anywhere in Alaska But luckily, I can get the alcohol easily.

 

[2cb]

Yes

Yes

neem meal and mosquito dunks work well for me.

I did read the sticky thread on fungus gnats where I saw this mentioned, but I am not able to acquire specialty products easily, and shipping is very expensive to my location. I should add that the covering over the container is important. The larvae had to escape the dirt/alcohol, and I can see them all dried out and dead on the Saran Wrap covering. They just dried out in an attempt to stay out of the dirt and alcohol.

And I did note that the Mosquito Dunks are cheap, 6 for $10 or so, so I guess this is just for people that live far away from specialty shops and warehouse stores. Also, the alcohol is fairly inert, easily acquired, fairly cheap ($1 / 16oz) and should evaporate on it's own over time. It's actually close to 3 days now, 72 hours, and no sign of anything alive. I had them so bad they would coat fly paper in black within a day. In my coffee and drinks, everywhere. That's why I got a little ecstatic. My whole home is free of them now. They are fucking annoying

 

[2cb]

Also, I would expect the rubbing alcohol (91%) to kill a lot more than just these bugs. It probably kills fungus and lots of other bugs. I would expect it to be fairly non-specific, but plants don't seem to mind it at all. And it is known to cause severe intestinal distress.

 

[2cb]

I could be wrong, but I am assuming that the larvae are about 3/8in long, and kind of a luminescent clear/white worm-like thing, with a black mouth. It was funny to see them under a microscope - the larvae's black jaws would arch around and bite their own bodies from the itching or irritation. They are basically tubes with black jaws at one end, pretty much just jaws and intestines. I think the alcohol also destroys much of their slime protection.

 

[2cb]

And for people unaware of what fungus gnats are, they can be uniquely distinguished by their long front legs. They stand and walk much like a hyena or an ape - on all legs, the front of the body is in an almost upright position. And I assume that the larvae are much bigger than the fly form. The fly form is frail and only 1/8-1/4in.

 

[2cb]

Also, this may be a good method for "sterilizing soil" between grows, if you can't microwave it or do some other thing to begin a grow with pest-free soil (using a higher alcohol concentration since the soil is without plants).

 

[2cb]

And I should note that the plants are big and heavy drinkers at this time, so I am able to "waterlog" the soil completely with the alcohol solution, which may be kind of important.

 

[window]

The best way for me was biological using Hypoaspis that eat the larvae and sticky traps for the adults, hope this helps.

 

[BobBitchen]

It's been my experience that Fungus Gnats party on DE like it was beach sand.
Mosquito dunks work the best for me also


✌

 

[2cb]

I can't comment on the Mosquito Dunks, but they certainly don't party on Isopropyl Alcohol. If not queched and dead already, they walk around with their wings up in the air, acting drunk, and then fall over into a wet spot, and then they die within minutes.

 

[2cb]

I just saw one of these red-orange little spiders that run around super-fast, probably many people have seen them at one time or another. Less than 1/8in, but very fast, and they seem to run in any direction equally as well with radial type legs. Anyway, I nudged him into a little droplet (smaller than his body) of the solution on the Saran Wrap, and he was dead in about 30 seconds. It does appear selectively toxic to bugs, while fairly non-toxic to plant life (at least in these dilutions).

In another houseplant pot (Datura Stramonium), there is these little speck type bugs that seem to jump long distances fairly quickly. They look grayish, kind of like speck-size armadillos. Anyway, they are all stoned out on the part of the pot above the water/soil line. They can hardly move just from the fumes of a 3% solution of Isopropyl Alcohol. And when I tap the side of the pot, they just fall off into the dirt.

 

[2cb]

My observations correlate to toxicity studies, and would seem to affect animals much more so that plants:

http://toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@term+@DOCNO+116

HUMAN EXPOSURE: Toxic effects include central nervous depression, liver, kidney, cardiovascular depression and brain damage. It can cause drowsiness, ataxia, stupor, coma and respiratory depression, irritation of mucous membranes and eyes, gastritis, gastric hemorrhage, vomiting, pancreatitis, cold clammy skin, hypothermia, miosis, tachycardia, slow and noisy respiration.80% of an oral dose is absorbed within 30 minutes. Absorption is complete within 2 hours although this may be delayed in a large overdose. Alveolar concentration is correlated to the environmental concentration at any given time. Isopropyl alcohol is absorbed through intact skin on prolonged exposure. Isopropyl alcohol distributes in body water with an apparent volume of distribution of 0.6-0.7 L/kg. 20-50% of an absorbed dose is excreted unchanged. Most isopropyl alcohol is oxidized in the liver by alcohol dehydrogenase to acetone, formate and finally carbon dioxide. Acetone is slowly eliminated by the lung (40%) or kidney.

ANIMAL STUDIES: Isopropyl alcohol most closely follows first order kinetics, with a half life of 2.5 to 3.2 hours. The elimination half life of the active metabolite acetone is significantly prolonged to about 5 hours in rats. In rat hepatocytes the following has been observed: marked depletion of glutathione, increased malondialdehyde production, decreased protein sulfhydryls content and leakage of lactic dehydrogenase with loss of membrane activity. Isopropyl and n-propyl alcohols are about twice as toxic as ethanol; the fatal dose by ingestion is 250 mL. ... The principal manifestation of acute isopropyl or n-propyl poison is CNS depression. Symptoms and signs: (From inhalation, ingestion, or skin absorption) ... persistent nausea, vomiting, abdominal pain, hematemesis, refractory ... /CNS depression/, areflexia, depressed respirations, and oliguria followed by diuresis. Deep coma has resulted from sponging with isopropyl alcohol. Generalized tenderness, induration, and edema of muscles may occur. ... Prolonged contact with the skin can cause corrosion. Isopropanol intoxication has a rapid onset of action (30-60 min), with peak effects within several hr. ... Severe poisoning presents early with deep coma, resp depression, and hypotension.

Central nervous system: Dizziness, poor coordination, headache, and confusion progress to stupor, coma, and loss of deep tendon reflexes in serious cases. Serious nervous system depression often persists for 24 hr. ... Pupils often are miotic, and nystagmus usually is present.

Gastrointestinal tract: Gastric irritation appears early, with abdominal pain and vomiting being prominent. Hematemesis may occur.

Cardiovascular system: The hypotension associated with large overdoses probably results from peripheral vasodilation. ... Tachycardia was the most common finding ...

Organ dysfunction: Cases of acute tubular necrosis, hepatic dysfunction, hemolytic anemia, and myoglobinuria have been reported. ... Mild hypothermia may occur ...

ISOPROPYL ALCOHOL HAS GREATER FAT-SOLVENT EFFECTS THAN ETHYL ALCOHOL, REPEATED USE HAS A DRYING EFFECT ON THE SKIN. ISOPROPYL ALCOHOL IS MORE TOXIC THAN ETHYL ALCOHOL AND LESS TOXIC THAN METHYL ALCOHOL. ... ITS ACUTE POTENCY AS CENTRAL NERVOUS DEPRESSANT IS ABOUT TWICE THAT OF ETHANOL. PROBABLE LETHAL ORAL DOSE FOR ADULT IS 8 OZ (240 ML), BUT AS LITTLE AS 20 ML IN WATER CAN PRODUCE SYMPTOMS.

TOXICOLOGY: CNS depressant and gastrointestinal (GI) irritant; acetone (metabolite) likely contributes to CNS depression.

MODERATE TOXICITY: May include CNS depression, dysarthria, ataxia, nystagmus, similar to ethanol intoxication, nausea/vomiting, flushing, headache, tachycardia, mild hyperglycemia, ketonuria, and ketonemia WITHOUT metabolic acidosis.

SEVERE TOXICITY: May include hemorrhagic gastritis, hypotension, respiratory depression, and coma. Death is rare and likely secondary to respiratory depression and aspiration.

DERMAL EXPOSURE: Repeated dermal application can cause systemic toxicity (primarily CNS depression), especially in infants and young children, because of more extensive dermal absorption and greater surface area-to-volume ratios.

 

[2cb]

Isopropyl + Plants

Isopropyl + Plants

It seems that many people use Isopropyl Alcohol to kill pests on plants, though no studies on using it in soil; so I will report back in several days to let people know if it causes damage when used as described:

http://www.google.com/search?q=isopropyl+alcohol+plants

How does rubbing alcohol affect plants?

Science Supervisor Hooweestik

On the Cornell University they used alcohol on a plant and here are the results from the Cornell University, states "We think it simply might be water stress; that is, the alcohol makes it more difficult for the plant to absorb water, so the plant suffers a slight lack of water, enough to reduce leaf and stem growth, but not enough to affect flower size or flower longevity."
--
I am in flowering with some 5-6ft sativas which drink about 3 gallons every 2 days (and I'm an ultra-leaf-picker, leaving only single leaflet leaves on during budding).

 

[Jhhnn]

Interesting technique, particularly for members who can't access alternatives. I use repackaged gnatrol from amazon. Whatever they were, those gnat-like winged assholes that messed with my last grow have been obliterated.

 

[2cb]

Plants Dehydrated

Plants Dehydrated

After 4-5 days, the leaves of the plants are drooping, so it appears that Isopropyl Alcohol will dehydrate plants at 3% concentration which fully saturates the potting material. I will post later in a week or so to state the outcome of the plants, eg, whether this resulted in a setback or death.

However, it still may be a good way to "sterilize" soil between grows IMHO. All bugs remain all dead in all pots saturated with a 3% solution.

 

[Granger2]

OK so it killed all the bugs. Now, to keep it from killing/damaging the plants I would give them a heavy watering to get the Al key hall out of the medium. Or you could try it on half the plants and compare for future reference. Be sure to keep the rest of us informed about your results. Also, the microherd was probably killed so you'll need to inoculate with EWC ACT or something like Great White. Good luck. -granger

 

[intotheunknown]

I managed to rid of the little fuckers after a long battle and trying various things that wouldnt work. Plus I dont believe in chemicals, etc. Also a living soil grower.

Neem oil soil drenches and very aggressive sessions with a shop vac.
All I had to do was keep eliminating the adults, eliminate any breeding possibility and the neem prevented larvae from developing.