Howdy @Miku, and not to speak for @AzSeaindooin420 to who you originally asked the question, there is a product I’ve heard of that contains bacillus thuringiensis as an active ingredient at approximately 8% if it’s volume. The product is called Microbe-Lift BMC and is advertised to control mosquito larvae. I believe BT and BTi target the worm/larvae stage of these developing organisms.
Just seeing the recent comment regarding methonyl 90 and the claims of toxicity are worrying. What about methonyl would be the best? I’m unfamiliar with the product but a quick armchair research has me thinking it’s some nasty dangerous stuff. The claims of toxicity to fish and aquatic invertebrates along with EPA grouping it as category 1 toxicity seem worse than the damage caterpillars can do.
The Microbe-Lift says it has no toxicity to fish and no toxicity to non-target invertebrates. My accumulated knowledge in this area is novice and will have bias of ignorance, even still I hope these comments are helpful to others. Much love