Study of nectariferous secretion in a pioneer plant, Inga thibaudiana, in relation with ants

The foliar nectaries secretion of a shrubby pioneer species, Inga thibaudiana (Leguminosae - Mimosoideae), was taken during 24 hours cycles in the dry (October - November) and the wet (march - April) seasons. The comparison of secretion rythms shows the production always starts at the end of the photosynthetic period, and it probably depends on the supply of water to the plant. The plant quantitative production equally depends on vegetal foliar growth. The continuous exudation of nectar attracts many ants on all the vegetative parts of the plant. The listed species on a hundred Inga thibaudiana shows that such plant-insect relationship isn't specific, but has been set up secondarily, contributing thus to ensure a kind of biotic protection. This protection seems effective, since scientists have never met with completely defoliated Inga tree. However, ii we consider the limb in adult leaves, growing leaves and young leaves more closely, we will notice that the limb of the growing leaves is essentially damaged by herbivorous activity. However, at this foliar stage leaves are less tough and need a specific protection. The active production of nectar on this kind of leaves, as well as the numerous presence of ants, don't seem to be sufficient factors to protect the vegetal efficiently. This ant-plant interaction makes clear the complexity of the reciprocal relationships as they are set up and their link with environmental factors.