Is deltamethrin harmful to plum trees against insects?

yes. Bromocyanide, also known as cyanamide, is a second-generation ornithine receptor inhibitor pesticide successfully developed by DuPont after the introduction of chlorantraniliprole. Cyanide is made by changing various polar groups on the benzene ring, which is more efficient, more applicable to crops and wider in insecticidal range, and can effectively control dozens of pests such as Lepidoptera, Hemiptera and Coleoptera, but its disadvantage is that it is toxic and harmful to plum trees.