They arrive in bunches of bananas; they turn up in containers of vegetables; they sneak in hidden inside rattan and wooden furniture; they disembark from among shipped household possessions, industrial and military equipment. They are as pervasive as the computer server virus Nimda, but, in their own way, far more destructive.
What are they? Not illegal immigrants but aliens nonetheless -- and seemingly Japan has no laws for restricting either their arrival or their dispersal.
These aliens are capable of withstanding chilling; gassing; changes of pressure; and lack of both water and food for prolonged periods. They are the most successful living creatures on Earth: They are insects.