What kind of diseases can effect a black locust tree?

Answer 1

This depends on your location. In the US, the primary enemy of black locust trees is a boring beetle, the locust borer. Nearly all locusts everywhere are affected by it and it kills most locust trees before they can become very large. This beetle is the main reason why US black locust, a high quality hardwood, cannot be used for furniture, as the beetle ruins most black locust wood before it is big enough to use for furniture. If you cut down an affected tree but leave the root system intact, you will probably get several more trees growing up from it.