Pollination of young palm trees in Asia is mainly due to an introduced wee- vil, Elaeidobius kamerunicus. The pollinators congregate and multiply only on male inorescences in anthesis (during ower opening). Then, loaded with pollen grains, they may visit female owers and pollinate them, more or less, e_ectively. However, this entomophilous pollination is not always su_cient to have a good fruit set. In particular, because the density of male inorescences per hectare is often low in (young) plantations. That is why it is important to study and understand the mutualistic interactions between the inorescences and the weevil population, despite the fact that we have partial knowledge. The aim of this talk is to present a mathematical model and to compare it with an Individual-Based approach [1]. Using the qualitative analysis of the mathematical model, and numerical simulations, we will discuss the main out- comes of both models that may help us to elaborate new observations, new experiments, or to understand how to sustain this mutualistic system. Finally, based on old published data [2], we try to estimate the mean number of male inorescences per hectare necessary to maintain a population above a certain threshold in order to reach a good fruit set.