What startling event did Mary experience while driving in the car with her mother to Lubbock as a child?

When Mary was a child, Charlie threatened to divorce Pete and drove the girls to Lubbock to stay with her mother. On the way, Charlie's car was attacked by a swarm of locust. Mary remembers some of the insects getting into the car through the open windows and flying around. Mary blacked out from fear and did not return to consciousness until the family had safely reached Grandma Moore's house.