Anticipating the establishment of pest reservoirs, and therefore pest infestation in sugarcane agrosystems, is a challenge for the implementation of integrated pest management (IPM) programs. The objective of this work was to develop a decision support system that suggests host plant species and pest natural enemies located in a production area. A knowledge base system (KBBI) was developed and coupled to DECIPESTS, a decision support system for PEST management in sugarcane. According to an observed damage, KBBI suggests the wild and cultivated plants that host the potential pests previously identified by DECIPESTS. The comparison with a local floristic inventory enables to determine pest reservoirs. Applied to a case study in Senegal, the system showed, for instance, that Eldana saccharina can be hosted by nine wild plant species located in the irrigation canals and two neighboring cultivated crops of socioeconomic importance in the area. This latter result indicates that the management of Eldana saccharina has to be tackled jointly by local farmers to be successful. While DECIPESTS uses a tactical approach to identify possible causes of pest infestation, its combination with KBBI makes it a strategic tool to enhance IPM strategy at a local scale.