In the framework of the European project SOLABIO (INTERREG IVA, 2009-2012), the Flemish Land Agency (VLM) launched a sur- vey to estimate the potential added value of different types of field margins for the survival of butterflies, carabid beetles and flying insect species which are known as winged natural enemies of crop pests. The abundances and diversities of butterflies on monitored and newly cre- ated field margins surrounding arable fields or pastures and control sites were compared at several locations in Western and Eastern Flanders. This study indicates that an adapted duo-management of field margins (i.e. mowing each year only half of the field margin) can give the best results for butterflies when the field margins are already low in nutri- ents. Several years of mowing and removing cut material, impoverish- ing the field margins, seems to be a necessary prerequisite for a success- ful duo-management. In the province of Limburg carabid assemblages were sampled in arable fields and surrounding field margins and com- pared. Several rare carabid species had vital populations in managed field margins. The number of individuals increased when sampling further in the arable field compared to the field margin. However, the number of species and diversity decreased when sampling further away from the field margin into the arable field. Our study suggests that an adequate management of field margins in the framework of ‘functional agro-biodiversity’ (here with focus on pest-management) is feasible and yields in advantages for farmers, landscape and biodiversity

*Biodiversity, insects