Fig. 1

Flow chart visualizing main model processes from a beetle perspective. Each single beetle starts from a source with its individual physiology (energy level, efficiency), jointly with a specified number of conspecifics at a certain point in time (1). At every movement step the beetle checks its energetic resources (2). As long as energetic resources are sufficient it continues the dispersal flight (3), otherwise the beetle suffers mortality due to energy deficiency (4). Dispersal continuously reduces the initial energy level according to the individual-specific consumption efficiency. Movement follows a correlated random flight until the beetle perceives an attractive host within its perceptual range which pilots it directly to that host. The decision whether to attack (6) or to continue dispersal (7) is made according to the actual attack propensity (5) which is based on its fatigue level and the encountered relative host attractiveness. Once a beetle attacks a host it will depend on a certain number of conspecifics to overcome host defense mechanisms (8). Only if this threshold number is achieved the beetle attack is successful (10), otherwise the beetle suffers mortality due to host resistance (9). For details see also Table 1 and Additional file 1