Answer:
The population of beetle would mostly consist of green beetles.
Step-by-step explanation:
Green colored beetles would have survival advantage in grassland as they can blend themselves within the green colored background of grasses. This would protect them from their predators. On the other hand, the red colored beetles would be easily located by predators and would be killed. So, in time, the beetle population would mostly consist of green beetles owing to their survival advantage in grassland environment.