Abstract
Resistance and tolerance, which is the ability of plants to endure a pest attack, are two different aspects of plants defenses. Tolerance is strongly linked to a compensation process which is a positive response of plants to the presence of pests (in terms of reproduction and / or growth). In order to bring new knowledges in the field of plants-insects interactions, we conducted three different studies on compensation in plants. In the first one, we developed a generic mathematical model, whose the study revealed the existence of threshold parameters that determine the co-existence or not of different types of compensation equilibria. The second study, which was experimental, aimed to test the hypothesis of a compensation response in tomato undet the attack of the tomato leafminer, Tuta absoluta. In our experiment, the tomato cultivar presented trends in compensation for two levels of infestation, and trend of reproductive overcompensation for low infestation. Finally, our last study is based on a "Structure-Function" computer model, still on the case of tomato and T. absoluta. This model was used to test and visualize different situations (dates and positions of the attack) on a more realistic representation of the plant. In conclusion, we have shown that compensation may have a significant impact on the effectiveness of strategies for crop protection and must be taken into account in their development.