Complex sentence: If the body of the insect rotates about one of its three axes (yaw, pitch or roll), the rotation exerts a force on the vibrating halteres, known as the Coriolis effect (see below).
Split into simpler sentences: If the body of the insect changes direction in flight or rotates about one of its three axes (yaw, pitch or roll), the rotation exerts a force on the vibrating halteres. This is known as the Coriolis effect (see below).