Inga species

This photo shows one of the many fascinating plant-insect interactions to be found in the jungles of the tropics. Here you see an ant taking nectar at what is called an extrafloral nectary. The plant derives none of the "normal" benefits from providing this source of nectar. The ant is not pollinating any flowering reproductive plant parts in exchange for the nectar; however these ants will ferociously defend the leaves of the plant from herbivorous creatures, insects, etc. that would eat the vegetation of this plant. If you brush up against this plant, the ants will swarm to you and defend the plant in exchange for the "free" nectar. This is a case where the plant has adapted to grow these nectar-producing parts solely for the purpose of attracting these ants for defense. Creatures in the jungle like butterfly and moth caterpillars, small mammals, etc. will often target the new growth leaves to eat, which are softer and contain more nutrients. Inga produces nectar at these nectaries only near the new growth leaves. When the leaves age and harden the nectaries dry up and the ants must move to the new growth to obtain the nectar on which they survive, where the plant needs the protection most. We find these types of interactions to be fascinating and a joy to see first-hand.