How many aphids are there per tree?
At least 1 aphid specie
No one knows the exact number of aphids per tree. The number varies. Anyway, according to the website www.uri.edu, almost every plant has one or more aphid species on it. What are aphids? They are small, soft-bodied insects with long, slender mouthparts with which they pierce stems, leaves, and other tender plant parts to suck out plant fluids. There are many species of aphids. Some insects may be green, yellow, brown, red or black, depending on the species and the plants they feed on. Unfortunately, aphids have many generations each year.