Does anyone know what these are. At first I thought they were fungus gnats. But there are no flying insects in the grow room. I’ve had fungus gnats several times and they fly all around the grow room. There are some dead flyers on the sticky pads (they are blue) with wings but I haven’t seen any flying around. There are thousands of what look like larve with a body and two antennas on each sticky pad. They don’t look like fungus gnat larve. I have 16 sticky pads and they are all pretty full of this strange bug, mostly larve, not many that fly. They are all on the top of the pads, none on the bottom touching the dirt. How did thousands of what ever they are get on the top of the sticky pads and where did they come from. These just appeared during the 7th week after switching to 12/12. Today starts 9 weeks since I switched to 12/12 and the plants are looking good. Does anyone know what these are?
You may not have seen any flying but they have wings so definitely a flying insect. My gut tells me a species of gnat… don’t get hung up on fungus gnat and force a square peg through a round hole. My guess is if you are in a controlled environment that your medium already had the larvae present and the infestation got out of hand very quickly. A few questions…
What medium are you using?
What are your environment conditions? Specifically outdoor grow, indoor, tent, grow room, temp and humidity???
How often are you watering? And to what if any amount of runoff?
Have you introduced any new plants since the switch?
Have you taken the plants out of this environment at all?
Are you doing any preventative pest management?
Generally speaking, what region of the world are you in? For example south east USA
Either way you have a problem, and we need to fix it. Let’s dampen off the amount of water your giving the plant for awhile. Dry it out a bit longer than you normally would. Let’s bring rh down a bit as well and make conditions less hospitable for pest.
Thank you for all the replies. The larvae do look like sprintail and the bugs look just like eye gnats. I don’t need to control them because they are just about ready to harvest. I don’t like to use chemicals but have hat to once to control a very bad fungus gnat problem. I used a product called 8. Hydrogen peroxide did not help.
What medium are you using? I make hot soil starting with all purpose Pro Mix
What are your environment conditions? Indoor grow closet 4’ X 12’, temp around 80 day an 70 at lights out, the humidity is a bit high even with a dehumidifier. 65%
How often are you watering? I water 3 gallon smart pots with 1 gallon of water about every 7 days. And to what if any amount of runoff? very little runoff
Have you introduced any new plants since the switch? no new plants. These sprouted on 1-29-19
Have you taken the plants out of this environment at all? no
Are you doing any preventative pest management? just yellow sticky pads
Generally speaking, what region of the world are you in. Northeast US, Maine
No way it could be spring tails since adults do not have wings. That’s odd, one gallon every 7 days shouldn’t cause this level of saturation for ideal conditions. If you were doing 1 gallon every day or every other day I’d say bingo. I do stick by my original statement that I think your soil had larvae present already.
I’d work to clean my space out really well with some type of product. Essentria IC3 is a “natural” product that you could use to wipe down grow space once your finished with this run. Maybe mix in some BTi when making soil mix for next run and I know with houseplants you can put a layer of sand (about 1-2”) on top of the soil to prevent gnats from laying eggs if you do have them present again. Idk if this will affect cannabis never tried it. I use pt alpine fly bait aerosol for my gnat control whenever I see a few pop up.
It’s a pretty common technique in cannabis cultivation. That and a similar layer of gnat gnix. I tried it with gnat nix and found that every time I watered, the medium would mix with my soil, and after several weeks the gnats were at full force again.
The only thing that worked to eradicate fungus gnats in my grow was BTi.
Yeah you would have to maintain a 2 inch barrier. The thought process is that the gnats won’t burrow down and lay eggs in the sand and they shouldn’t go past 2 inches or so of sand. No organic matter for larvae to feed on in sand. I’ll try to do some research and find a strain of bti that works best on gnats. I know everyone wants to stay away from pesticides but… an IGR would work really well for a long period of time. Something like tekko pro. But not sure how it would taste lol might wanna avoid that. The alpine works wonders and never touches the plant
Thanks everyone.
I do clean the grow room after every grow with Clorox Spray. This grow was weird because the bugs didn’t show up until 12 weeks from sprouting, the 7th week of flowering. I will have the BTI on hand for the next grow. Are there instructions on how much to use in the soil. I am familiar with the product for small ponds. I know the pucks are for killing mosquito’s in small yard ponds
I have always used Miracle Grow seed starter and seem to get gnats every other grow. I’ve just planted seeds. This time I am using Fox Farms I bought in a grow shop. Hopefully I will have better luck, like no gnats.
I think there’s pucks and granules that both containing BTi read the label on the pucks if you have them you may have what you need as this is also for mosquitos too.
I will just sprinkle the granules on top evenly around not having to cover all just randomly spread and water and that releases / activates the BTi
You can also premix with water and then water in. If you have the pucks you’ll probably want to shred them up and then do one of the above with the smaller pieces if they have Bacillus thuringiensis subspecies Israelensis
