The force on the bug and the force on the bus are the same.
Explanation:
Newton's Third Law of Motion states that, "For every action, there is an equal and opposite reaction" or it can be restated that If a high-speed bus exerts a force on an innocent bug, then the innocent bug must exert a force of equal magnitude and opposite direction back on the high-speed bus.
Note: though the forces are equal but the effect are not, in this case the innocent bug was splattered but the bus was not destroyed.
