Invading moth imperils symbol of Mexico

MEXICO CITY -- A tale of nature's revenge, stretching back morethan two centuries and halfway around the world, has come full-circle in a battle of cactus, moth and man.

At stake is the survival of a Mexican national symbol.

The dull-colored cactus moth that reached Mexican territory thissummer threatens to devastate the country's nopals, the prickly pearplant that graces the country's flag and is deeply interwoven in itshistory, culture and diet.

The moth didn't migrate here from its native South America;mankind carried it -- to Australia, South Africa, and finally theCaribbean. That makes it a cautionary tale about the dangers oftransplanting species, …