Q.Brugmansias
Something is eating the Brugmansia’s leaves. What can I do?
Spider mites, aphids, and cabbage worms are among the most common pests of this plant--all of which can be taken care of by treating the plant with neem oil. Here is more information: https://www.gardeningknowhow.com/problems/pests/neem-oil-uses.htm
If you don't see any signs of insects, it could also be attributed to slugs, which normally come out and feed at night. This article will help: https://www.gardeningknowhow.com/plant-problems/pests/facts-about-slugs-and-how-to-kill-garden-slugs.htm