Whats liquid Bti?
BT stands for Bacillus thuringiensis. It’s a common soil bacterium that destroys the larvae (caterpillars and maggots) in many flying insects. It rots them from the inside out when they are immersed in it. It is considered organic and safe on edibles. It is the active ingredient of the mosquito dunks. It kills mosquito larvae too. It’s fish safe too. It is like an atomic bomb on fungus knats if you have the concentration right. Targeted and highly effective.
BTi is the variant that is from Israel. It was found accidentally in a stagnant pond. Someone noticed that the pond never had mosquitoes and sampled. Hence the discovery of Bacillus thuringiensis israelensis. It is supposed to reproduce faster than other BT, so it persists longer after a dose. Most all commercial mixes use the Israeli variant now.
Oh that’s the bacteria is spinosad isn’t it.
Spinosad is an entirely different bacterium. But same idea. Spinosad was found on abandoned rum casks at an abandoned rum distillery. What I wonder is who thought, what will happen if I spray this on my plants. Hmm.
Unfortunately it is not considered very affective against fungus knats. I do love Spinosad too for spider mites and leaf critters.
2 Likes
Man you are a wealth of knowledge. Very interesting
BTi -Is there any side effect or down side to drenching organic soil with it? Does it hurt any beneficial bugs, bacteria, or fungus?
It is considered as a safe as Spinosad. It is fine with living soil. If you have living soil, the soil fauna just outcompete the BT spike. Basically until the microbes are back into equilibrium. I would argue that living soil reduces the effective time of the treatment. You may have to do it 3 times in a week instead of just one. Say as opposed to sterile (iSh) soil or soilless media. The BT will have a living monopoly that last longer.
BT is in “normal’ soil as part of the soil micro biome. It is in very small amounts normally on an equal biological playing field. Not enough to dominate or be fatal to any but the random knat larvae it touches. But load up the soil to dominate and all of a sudden you have an extinction scale event for the knats. In a short window. Hope that makes sense.
You could also do diatomaceous earth. It is just mechanical control. The diatoms are like microscopic shards of glass. They literally slice up and bleed out the larvae as they wiggle thru the top layer of soil. That is where the adults lay the eggs. One must tape off the drain holes a few days or they slip in the bottoms. And water lightly. Standing water deactivates the D.E. So that’s the rub. Constant re dusting. And wear a mask. It is as bad for your lungs as asbestos NO JOKE give you mesothelioma. It does not work as fast. But is a valid alternative to BT bacterium.
My friend @CurrDogg420 also taught me to use Neem meal. You top dress the soil JUST like diatomaceous earth. But the water activates it. It is like a slow drip low dose systemic version of Azadirachtin. Or Neem oil. But does not make your buds smell like shi* like Neem oil concentrate. It is supposed to be living soil safe and compost down to a nitrogen feed. Many include it in their raw living soil mixes. If I did not like the BT I would maybe do both Neem meal and DE. It would be synergistic.
1 Like
A bag of DE and a bag of Neem meal I would bet cost 3x the price of a small bottle of BT. Mosquito dunks are even cheaper. If that helps you decide.
1 Like
Does BT or neem kill composting worms?. Bc I have those In my soil too
I know BT is safe for worms. I am in living soil and it has never killed my worms. It’s my go to for knats. You should see the knats my compost tumbler gets on hot stretches in the summer. Yikes.
I would suspect worms greatly dislike Diatomaceos earth cutting them all up. Neem meal is living soil safe. But honestly I have never needed to add it to my worms so I cannot personally say. I wish my friend Currdogg was still around. He was a Neem meal fan and a worm man. But sometimes there’s trade offs.
I wish the sticky traps could cure it. Sometimes they catch a few and that’s the end. But once there is uncountable amounts of knats it needs to be addressed. Otherwise you will have sticky buds covered in knats like the sticky paper looks. No good. Even if they left the roots well alone.
2 Likes
Thank you. I think I’m getting it under control. A lot less now and I’ll be fine by more flowering
1 Like