If the caterpillar has already made itself at home in your marijuana crop, it's vital that you act as quickly as possible. Take note because here are some biological remedies that you can use:
Manual removal: Armed with patience and plastic gloves, you can remove any caterpillars that you find on your plants.
Spraying: You can combine manual removal with homemade insecticides, such as a blend of pepper and garlic. Pyrethrum and rotenone also work very well. Use
Bacillus thuringiensis: We recommend this biological insecticide as the most effective method for treating caterpillar infestations. This insecticide acts upon contact, which means that caterpillars fall ill and die when they are sprayed with Bacillus. You should remember that even though it is a biological product, it is advisable to play it safe and refrain from applying it during the last 15 days of the cycle. It is also a good idea to combine sprays of this product with manual removal.
Introduce predator species: Trichogramma wasps and Podisus maculiventris can be quite helpful.
Hopefully, I answered your question and remember Happy Growing and Free your mind one puff at a time.