in the region i live, there's the possibility to got some trees for free ( Italy, Emilia romagna), almost 100!
And, i think to got also some trees that can be useful to my studies about moths, in particular some non-invasive host plants, especially that ones that they feed in nature.
The first is Prunus padus ( the Bird cherry); i heard about that it can be very very useful to feed Smerinthus, instead of willows, it withers very slowly than willows!
And, it's an Europea species.
The another one is Juglans nigra ( Black walnut), an American species. I think it's the species of walnut that Actias luna feed in nature, right?