[Wikipedia] Range, Induced Defenses: Catalpa bignonioides is a short - lived species of Catalpa that is native to the southeastern United States in Alabama, Florida, Georgia, Louisiana, and Mississippi. Common names include southern catalpa, cigartree, and Indian-bean-tree[(or Indian bean tree).It is commonly used as a garden and street tree. A 2003 study by J. Ness showed that when a hawkmoth caterpillar Ceratomia catalpae started eating the leaves of C. bignonoides, the leaves produced extra nectar. The nectar in turn attracted a greater number of bodyguard ants Forelius pruinosus to the damaged leaves, thus giving added protection to the whole plant. This is an example of a tree exhibiting a symbiotic relationship with nearby insects. (link added by Mary Ann Machi)