Definitions of overrun:

• noun:   too much production or more than expected
• verb:   run beyond or past
• verb:   seize the position of and defeat
• verb:   flow or run over (a limit or brim)
• verb:   occupy in large numbers or live on a host
• verb:   invade in great numbers
• adjective:   (often followed by `with' or used in combination) troubled by or encroached upon in large numbers

  Example: "The locust-overrun countryside"