Cactus Moth Threatens Mexico's Nopal Crops

By Lulu Garcia-Navarro

Published October 26, 2006 at 12:00 PM CDT

An unborn threat: The female cactus moth lays egg sticks like this one with up to 120 eggs inside. Once hatched, the larvae embed themselves in the leaves and eat their way through, leaving a pulpy mess in their wake.

Workers cut down diseased nopal plants on Isla Mujeres to try and stop the spread of the moth to the mainland, just six miles across the ocean.

In the town of Milpa Alta near Mexico City, Abrahm Avila tramps through his nopal field. The cactus moth threatens thousands of jobs and a national delicacy.

The nopal, also known as the prickly pear cactus, is more than just another succulent in the desert landscape of Mexico and the U.S. Southwest -- it's also a significant food source. Now an invasive moth is threatening many of Mexico's cactus species, including the nopal.

The cactus moth, Cactoblastis cactorum, a native of South America, has already infested many Caribbean islands and the southern United States. Now the pest has a foothold on the vacation hotspot of Isla Mujeres, a small island surrounded by sparkling aquamarine waters off the coast of Cancun.

The larvae of the moth are very efficient at eating cactus -- so efficient, in fact, that a memorial was dedicated to the moth in Australia, where it was successfully introduced to control wild cactus populations.

But in Mexico, the pest is a time bomb that threatens to destroy a lucrative food crop in Mexico. The government is responding by destroying infected crops and laying out traps to catch egg-laying females.

The moth may have arrived on Isla Mujeres last year, blown in from the Caribbean on the winds of one of the hurricanes that swept through the region. Mainland Mexico is just six miles across the water, where scientists say the moth could easily gain a quick foothold and spread rapidly.

That would be a disaster for the thousands who find work cultivating nopal in Mexico. It would also be a cultural blow -- the cactus has a revered place in Mexican culture and folklore.

As the story goes, the once-nomadic Aztecs were searching for a place to settle. Their shamans prophesied that the tribe would know the spot when they spotted an eagle, perched on a prickly pear cactus, with a snake in its mouth.

The spot where legend says the Aztecs spotted their eagle is now Mexico City, and the image from prophecy is now emblazoned on the national flag. But more than just a symbol, the nopal is eaten everywhere in Mexico, and is a key part of traditional Mexican cuisine.