article on the devastating cactus moth in Florida

[Eric in Orlando]

This was in the local fishwrap last week

http://www.orlandosentinel.com/news/local/...,0,136962.story

Monitor lizards, wild boars and armored catfish are among the foreign species that have grabbed headlines in Florida over the years as they caused trouble for residents or the environment.

But in the annals of worrisome pests, few have been alternately revered and feared by experts around the world as the cactus moth, a tiny insect with a devastating appetite for a certain type of spiny plant.

It's a bug whose relationship with humanity has been a bit like that of the Taliban's with the United States: an ally of convenience in one war, an intractable foe in the next. But unlike the Taliban, the cactus moth has the advantage of stealth on its side, even as it threatens to invade U.S. cactus country two decades after entering the nation through Florida. The tiny moth hasn't drawn the kind of public attention generated by Burmese pythons in the Everglades or the Mediterranean fruit fly in citrus groves statewide.

"It's not that sexy," said Robyn Rose, a program manager for the U.S. Department of Agriculture's Animal and Plant Health Inspection Service in Maryland. Problem is, exotic animal species that generate the greatest notoriety also tend to attract the most government eradication money -- meaning not so much these days for the cactus moth.

"We've got proof it can be controlled," Rose said. "It all comes down to resources."

The moth is a native of Argentina, where it behaves itself. In the 1920s, it was imported by Australia on purpose to devour a previously unstoppable stampede of prickly pear in that country. That particular cactus, which comes in dozens of species, is native to the Western Hemisphere but had been introduced to the folks Down Under as a gardener's delight -- only to become despised by farmers as it drove them and their crops from their fields.

The cactus moth, in its wormy, orange-and-black larval stage, eats the pads off prickly pear cactus, working one pad after another, from the inside out, until nothing is left of the plant but a desiccated mess. Pound for pound, it's one of the more destructive foreign pests in the world under the right, or wrong, circumstances, and it made short work of Australia's prickly pear population problem.

Australia celebrated the moth's handiwork with a stone monument in Queensland, inspiring South Africa, India and certain Caribbean nations to recruit the moth to battle their cactus invasions.

But taking the insect so far out of its natural habitat was sure to lead to trouble, and it did.

When the moth made its first U.S. appearance, in the lower Florida Keys in 1989, it promptly began to devour an endangered species of prickly pear there.

That set off tremors nearly 500 miles to the west, in Mexico, where cactus is a national symbol, cultural icon, food staple and cornerstone of desert ecosystems. When the moth finally appeared three years ago on a Mexican island eight miles from Cancun, the country took a scorched-earth approach, uprooting and destroying every prickly pear plant on the island. And in the past two years, the Mexican government has contributed $1 million to fighting the moth inside the United States.

"That's a lot of money to us," said Rebeca Gutiérrez, manager of that nation's moth-eradication program in Mexico City. "This is a big deal for us. We have worked hard in the fields, in the environment, in schools for awareness, everywhere."

After arriving in South Florida, the cactus moth had migrated north along both Florida coasts in the 1990s, swerving inland to some extent to infest Orange and Osceola counties. Since then it has spread almost as far north as Charleston, S.C., and west along the Gulf Coast into Mississippi.

The insect in its flying form hardly draws attention to itself. It is indistinguishable to the untrained eye from ordinary moths fluttering about our porch lights.

The nation's anti-moth strategy so far has boiled down to this: Fight it as aggressively as possible with the few weapons available, in hopes of pushing it back to Florida -- bedeviled more than most states with invading animal and plant species -- for eventual extermination.

Efforts to repel the moths' westward flight have included the mass removal of prickly pear in various places, including the near-denuding of Alabama's Dauphin Island. Rapid-response squads are often deployed to Petit Bois, a barrier island off the Mississippi coast near that state's border with Alabama.

USDA scientists have synthesized the sexual scent of female cactus moths and used it as a lure in traps put out to detect the insects' presence. Scientists also have perfected a technique for sterilizing day-old moths with a jolt of cobalt radiation; the neutered bugs can be released by the tens of thousands a week at infestation sites to breed with the exotic species (but not with the native moths) to stall the invaders' reproduction rates.

"This is about as species specific as you can get," Jim Carpenter, a USDA research entomologist in Tifton, Ga., said of the irradiated decoy. "It doesn't mate with any other moth."

Despite such efforts, the moth was discovered just a few months ago on levees in southern Louisiana. News that the bug has advanced even farther from Florida and that much closer to Texas came as a shock to the experts fighting its spread.

"There's no way we can hang a net over the Sabine River [which separates Texas from Louisiana] and say, 'OK, you moths, stay in Louisiana,'" said Barron Rector, a Texas A&M University professor.

Texas, where cactus dominates the landscape even more than palms do in Florida, is seen as the big domino no one wants to fall. Experts suspect that, if the Lone Star State becomes infested, then New Mexico, Arizona, California and Mexico would soon follow.

In Florida, eradicating the moth will be difficult because it is now so solidly established. Doria Gordon, a scientist with the Nature Conservancy, said the state's prickly pear head count has probably been reduced substantially. But the loss of cactus here and any overall environmental effects are hard to quantify because there was no inventory of cactus in Florida before the moth arrived.

Gordon said that, until better moth-control methods are developed, the best approach is careful, cactus-by-cactus inspections, which her group does in its Torchwood Hammock Preserve in the Keys.

It's onerous work but doable and worthwhile in the case of the prickly pear: One of the world's rarest cactus species, it is found in only in the Torchwood preserve and on Biscayne Bay near Miami -- and it has already been snacked on by cactus moths.

Quick facts about the cactus moth

Moths stack as many as 80 eggs in an "egg stick" that looks like a cactus spine. Eggs hatch within a month and the larvae bore into cactus pads where they eat for as long as five weeks, emerging to spin a cocoon and become a moth within three weeks.

Moths have a wingspan of up to 1.5 inches; mature larvae are about 1 inch long.

Moths have been observed cycling through three generations a year in Florida, Alabama and Mississippi.

Larvae spend nearly all of their time inside cactus pads, protected against various control methods that use insectide.

Most effective control method: complete removal of all infested cactus — several tons at a time in some cases.

[fastfeat]

Great, just great... Look for Texas and Mexico to be devastated in the coming decade. Expecting the ag checkpoint on I-10 from LA to keep this pest out of Texas is like, oh, never mind...

Happy New Years all.

[Eric in Orlando]

Just what we need, another pest. Like the beetle that spreads the fungus killing native Persea but also infecting avocado trees now. But maybe it will get under control.

About 10 years ago we had a pest kill off the 3 big clumps of the native Opuntia stricta we had in our Arid Garden and a clump of O. ficus-indica, O. littoralis and O. basilaris. This was before I had really heard about the cactus moth. But it was a larvae that bored into the pads and it wiped them out in less than a month. We used a systemic drench but it was too late. Since then we have never had another outbreak. It didn't bother the large O. cochenillifera which is very prolific. It is naturalized in FL and don't know if it has been infected elsewhere in FL.

There are lots of brown Cuban anoles and the native green anole in our Arid Garden and lots of leopard frogs in the small pond that roam around. Also lots of toads and Cuban Tree Frogs too so maybe they are controlling it now. I hope so.

[gyuseppe]

eric Mediterranean countries are full of cactus , hope not to have an invasion !