I found my dahlia leaves eaten away overnight by black and yellow caterpillars or worms. How do I get rid of them?
Found Yellow and Black Caterpillars in Garden
Certified GKH Gardening Expert
They can be treated with products containing Bacillus thuringiensis (Bt), a natural bacteria that kill worms/caterpillars without harming plants. Neem oil may be helpful as well. Here is more information: https://www.gardeningknowhow.com/plant-problems/pests/pesticides/using-bacillus-thuringiensis.htm