Gnat attack :(

[magiccannabus]

I have a big problem going on right now and I am very frustrated! I haven't had a single sign of a plant pest in my grow until I planted a couple of seeds recently. I only planted a couple of them as a test thankfully, but I have a very limited number of them and am very scared to plant the others. My big plants are unfazed so far, thriving even, but all my seedlings and mid-sized(4-6 inch) plants have either died or are dying. I need to get flowering soon, but this setback has seriously hurt my plans to flower in waves. I've been pretty depressed about it.

Is it possible for fungus gnats to live dormant inside a seed? I ask because when one of the seeds broke the surface I noticed there was a hole forming in the side of it and eventually I saw a bunch of little white worms inside the seed. I checked my soil on all my plants and saw absolutely none of those. I just started to see gnats flying around though and like I said all my mid sized plants are fubar.

I normally use nicotine sprays to deal with this sort of problem, but some people have suggested that I should be worried about TMV. If I boil the tobacco into a tea for a sufficient amount of time would that kill any TMV that might be dormant in the brew? Does anyone know how tough TMV is outside of a host? I need to get my big plants cloned right now and I doubt that's going to work with gnats messing with everything. I can't figure out why the big plants aren't being killed like the little ones though. They have the same soil, but they also have a thick layer of "black forest mulch" over top of them that is mixed with cut up horsetail reeds and charcoal.

As soon as the problems started I sprayed 3-in-1 "organic" spray on them, put a layer of DE powder on top of the soil/mulch, and put out sticky strips. They still died....

 

[Mikell]

The larvae burrow in once the seed cracks, but perhaps they can chew through it, I am not sure there. I lost a few peppers seeds to this earlier in the year. Frustrating to say the least.

I don't find top dressing DE to be that effective unless you're bottom watering, but even then the little buggers will just use the drain holes as highways.

Larger plants have a large enough root mass that FG larvae aren't going to do enough damage to cause outright death, although a fungal/bacterial infection may well do it in. Seedlings/new starts and clones are much more susceptible.

Sticky strips, BTi and H202 (low chance of root infection) have worked the best so far, though BTi only effects an early stage of the FG and takes 2-3 weeks to become effective. Not so much help for someone trying to pop seed/clone. Azamax soil drench has worked well enough as a fast knockdown if you've got the mullah.

Can't comment on the TMV/nicotine spray much, but I think TMV fear is kind of overblown. How many pot smokers are nicotine junkies?

If you wanted to spend 0 doubloons, baking the starter soil and rearing them under domes would get you through to the point it can defend itself, more or less.

 

[Croptober]

I had a bag of ocean forest filled with them and didn't even know. Once I noticed the problem I bought washed beach sand from Lowes like 50lbs for $5, I spread it over the top of the soil to make layer of sand so when the larvae tries to hatch from the soil it kills them by ripping their bodies when they try to go through it. My infestation was pretty bad and once I did that I noticed a big difference and within 2-3 more days they were gone. Also yellow sticky traps hare your friend.

 

[RB56]

The large plants last longer because they have more and bigger roots. Gnat larvae will eat all of the little roots that are all little plants have.

I use Gnatrol when I see an infestation. Works every time. Non-toxic, etc.

Gnats are everywhere this time of year. They could have come in in your pockets or hair. Pretty safe to assume they didn't come inside your seeds.

 

[magiccannabus]

Thanks for the replies. I worry I won't be able to stop them. I live on the edge of town and there's lots of compost and manure around here.

They don't take over outside. What eats them? I want whatever it is that eats them to come inside too....

 

[RB56]

You can control them. Secret is making your plants inhospitable to their life cycles. I do this.

 

[Jhhnn]

Gnatrol- root drench 1 tablespoon/gal once a week for three weeks. It'll kick their ass. If I had any left after the third application, they were really shy.

http://www.amazon.com/Valent-Gnatro...e=UTF8&qid=1411689975&sr=1-4&keywords=gnatrol

Then 1 teaspoon/gal once a week thereafter as prevention/control.

 

[Mikell]

Thanks for the replies. I worry I won't be able to stop them. I live on the edge of town and there's lots of compost and manure around here.

They don't take over outside. What eats them? I want whatever it is that eats them to come inside too....

Nematodes! But the idea that you could harvest them from outdoors is near impossible!

Buying them, 25-40 bucks.

Gnatrol/Mosquito Dunks are pretty cheap.

 

[magiccannabus]

Thanks! For the moment I'm going to give garden centipedes a try. I have been doing some research and it seems that fungus gnats are something they specifically hunt. I caught about 6-8 of them out of my compost heap. They always live down low in the composter, where most of the bugs are. They move really fast but they can't climb so I throw them in an empty cottage cheese container. I put a pair of them in with one of my little plants that's struggling and the rest in with my least important big plant. I worry that the ones in the little planter might not survive since I've sprayed that recently. The big planter though is 100% au naturale and I have high hopes for them. I'm going to try to catch more of them tomorrow but I was running out of light this evening!

If they don't work I'm going to get some spray or dunk product. I don't know where to get gnatrol around here but Azamax is often at Ace Hardware. This is a bad time of year to find garden products, though on the plus side they're starting to go on sale....

 

[Mikell]

Gnatrol and Dunks are the same thing (BTi) and in the 5-10 range, Azamax is pretty pricey unless you find those single use doo-dads.

And fuckin' eh on finding a DIY way of doing it. Stoked to see how that works out. Got a pic of the little leggers? Not entirely sure what you're refering to.

Snap, just saw your other thread.

 

[magiccannabus]

I don't know how I'd get a pic of them, my camera is old and slow and they are VERY fast. They're just a standard small-sized garden centipede though. I think that other thread has a link with a pic of them. I'm going to capture some tomorrow and try to make sure each planter has enough to allow them to reproduce. I am so upset about losing precious and totally irreplaceable seeds that this is war!

 

[thatonedude]

mosquito dunks work great 100% of the time. ive never heard of them not working and they are organic. your basically just inoculating your soil with bacteria that eat the larva of insects

 

[DemonTrich]

captain jacks spinosad used as a soil drench. only use 50ml per 5 gal of water I. I use 10gal every watering, so my equations are for 5gals at a time. then 2-3 weeks later (3 weeks tops), hit them again. problem solved, no more gnat.

 

[EclipseFour20]

Mosquito Bits (made by the same people that make Dunks)...FTW! Same amount of BTI contained in "Dunks"--which are made from calcium carbonate & cork, Bits are made from corn cob bits and easier to measure/dispense. 30oz jug is less than $20. I add Bits to the my grow medium (when transplanting) and again as a top dressing.

 

[bigshrimp]

Sounds like a pretty serious gnat attack!

I get the gnatcontrol liquid and make a fairly concentrated mixture and put it in a sprayer. I mist and mist and mist the top surfaces of pots and down the sides. They seem to like the surface areas (+ or -) a couple inches. This way i can be sure that their breeding area is thoroughly saturated.

Neem and chitin meals can help in the long term.

 

[DemonTrich]

eclipse, you just add the bits to your medium and let the waterings melt down the bits? I might have to give this a shot next cycle. its a lot cheaper than the capt jacks spinosad.

 

[Former Guest]

what worked for me was mosquito bits bubbled in a tea and then applied to the soil. it says it is released in water and can be used in ponds so why not try and beef them up in a tea? when I used them by sprinkling on the dirt and working them into the soil and then watering, I found it not very effective.

I also used SNS 203 http://www.amazon.com/Sierra-Natural-Science-Concentrate-Pesticide/dp/B004HPRBDS

if you are low on cash but have a way to get or make clove oil and rosemary oil, this is a very easy product to make at home. all of their products use these two ingredients in different ratios with this being the mildest. I get them quite frequently in my soil and I keep these two products on hand using the SNS first and then using a tea to bubble the bits for any stragglers that haven't been taken down or survive. I was told it will kill your microbes so inoculating afterwards with a tea is best. I should probably add that I'm no expert but it's just worked for me IMO.

 

[VerdantGreen]

let the soil dry out as much as possible inbetween waterings, gnats are a sign your soil is staying too wet.

adding neem meal to your soil will help. ive stopped seeing them at all since i started adding it as a fert.

gnats arent a big problem and they are easy to get rid of.

VG

 

[thatonedude]

a layer of sand about a half inch thick on top will also keep them from reproducing. ive also heard of people using coffee filters the same way

 

[Jhhnn]

let the soil dry out as much as possible inbetween waterings, gnats are a sign your soil is staying too wet.

adding neem meal to your soil will help. ive stopped seeing them at all since i started adding it as a fert.

gnats arent a big problem and they are easy to get rid of.

VG

Gnats can be a bigger problem than most people think. Last grow, I tried to ignore 'em, other than using fly strips, ended up with blotchy leaf necrosis that looked a lot like pics of calcium def. Also noticed that the most affected plants weren't taking up water nearly as well as they should when I checked the heft of the pots. The effects didn't show until mid flower. Cal-mag made no difference.

Bad as it was, I thought maybe I had root aphids, learned here that those are spread with foreign cuttings. Growing from seed, the chances of it being that were extremely remote. When gnatrol killed 'em off, I knew for sure it wasn't root aphids, again with help from the forum. I'm sure that yield would have been considerably better had I figured it out earlier.

Using gnatrol at 1 tsp/gal once a week as prophylaxis def works. Even if they're accidentally introduced, the gnatrol beats 'em down so thoroughly that they should never be a problem. Once treatment at higher concentration was complete, my Victor fly catcher strips had zero gnats & I plan on keeping it that way.