Projects and methods are developed in Europe to mitigate species decline, both for entomophilous plants and for pollinating insects. In urban and agricultural landscapes, increasing projects concern the maintenance and restoration of plant-pollinator networks. For example, in agricultural landscapes, among AES methods, the managed flowered strips (and to some extend the hedges) aim to provide floral resources for pollinating insects. In cities, street trees are questioned for their potential benefits. The efficiency of such land planning needs to be evaluated. We performed mid-term studies on plant-pollinator interactions, based on the evaluation of the floral resources quantities and qualities and on direct observations of the interactions. For in several case studies of such practices, I propose to review and compare the most visited plant species and their resources for insect visitors. We will focus on the main pollinators in Western Europe, i.e. bees (Hymenoptera) and syrphids (Diptera).