Crazy ants to slimy worms: foreign pests keep coming
Many non-native pests, from fire ants to slithery, slimy worm-like creatures, have come into the U.S. and made themselves at home, often causing widespread economic damage and other disruptions to life and commerce, says Blake Layton, Mississippi State University entomology professor. “It’s important that we remain on the alert for these invaders," he says. "You never know when one will have the potential to be the next boll weevil — or even worse.”
In 1978, the horror movie, “The Swarm,” hit the nation’s theaters, featuring vast hordes of killer bees that wreaked havoc in south Texas.
Chockablock with big name stars — Henry Fonda, Olivia de Havilland, Michael Caine, Richard Widmark, Fred MacMurray, Richard Chamberlain, Ben Johnson, Lee Grant, Patty Duke, Slim Pickens — the $21 million production (a lot of money in that era) was a colossal boxoffice bomb, lasting only a couple of weeks in theaters.
Although it was subsequently labeled one of the worst disaster movies ever, four decades later it enjoys something of cult status among horror movie buffs.
“It was a cheesy movie,” says Blake Layton, Mississippi State University Extension entomology professor, “but it was also somewhat prophetic in that we’ve seen Africanized honeybees, which were dubbed ‘killer bees,’ move into the southern U.S. and become established.”
While not nearly so dramatic on a human scale as in the old movie, many non-native pests, from fire ants to slithery, slimy worm-like creatures, have come into the U.S. and made themselves at home, often causing widespread economic damage and other disruptions to life and commerce, he said at a recent meeting of the Starkville, Miss., Ag Club.
“So, in reality, we can say ‘the swarm’ is still coming.”
Africanized honeybees, which are a sub-species of the common European honeybees, came into Texas in 1990 and have spread from there, Layton says.
“Their movement has been more westward than east, although they’re in south Louisiana, only two parishes away from Mississippi. They are much more aggressive than our native honeybees — the analogy I use is that it’s like comparing a Labrador and a pitbull. When they do move into Mississippi, it will change the way we deal with honeybees.
“Even our ‘native’ honeybees aren’t native; they were brought here by settlers from Europe. The Indians called them ‘white man’s flies.’”
There are more than 1,700 significant insect pest species in the U.S., Layton says, and half or more have been introduced in one way or another.
“The boll weevil is a prime example of how a non-native pest can move in and wreak economic havoc,” he says. “It cost Mississippi farmers millions of dollars before it was finally eradicated. We’ve not had a boll weevil in the state in more than two years.”
Imported fire ants have spread across most of the lower Southeast and across south Texas and into parts of Oklahoma.
“Thus far, we’ve not been able to stop them,” Layton says, “and there’s nothing on the horizon that promises to halt their spread.”
Another species, Argentine ants, “have been here for a long time, but haven’t spread as fast as fire ants. South of Jackson, Miss., they’re quite abundant. They don’t sting or build visible mounds, and they’ll run off fire ants. The difference is that they will come inside houses and other buildings.”
Hairy crazy ants
Recently, the media have given a lot of attention to hairy crazy ants, also called raspberry crazy ants and Caribbean crazy ants.
“These began showing up in Mississippi about three years ago,” Layton says. “They also don’t sting or build visible mounds, but their populations can be really huge, and they will come inside in vast numbers. They don’t bother human food or pet food, but they can short out electrical circuits, well pumps, and other electrical devices, and if you disturb them they can be all over you in 30 seconds. They feed on other insects and plant nectar/exudates.
“Homeowners tell me they can kill them, but they may end up with a half inch thick pile of dead ants.
“We think they originated in South America, were then introduced into the Caribbean, and from there probably came into the U.S. on ships or in potted plants.
“At present, we know of two places in south Mississippi where they’re located, but we think they will spread rapidly. We don’t have any idea how far north they will move.”
Other non-native pests that have taken up residence in Mississippi or elsewhere in the U.S., Layton says, include:
• Land planarian: “It’s long like an earthworm, slimy like a snail, with a head like a cobra.” A predator of earthworms, it can be up to 12 inches in length. It has been in Mississippi for quite a while.
• Formosan termites: “They were first found in 1984 in coastal areas of Mississippi and now about 25 counties have infestations, including one documented at Tupelo in northeast Mississippi this year. They can eat a lot more, a lot faster, than the more common eastern subterranean termites.”