Top invader threats

Long after the fire ant arrived in the early 1900s, foreign insects, plants, diseases, snails and seeds still pose a threat as potential invaders.

They can hide in a variety of spaces, ranging from the dirt that’s caked on the underside of container boxes, the wooden pallets that cargo is carried on, and used farm equipment returning from overseas.

Estimates are that 50,000 plant, animal and insect species have been introduced into the U.S. throughout history, intentionally or by accident.

Among the top threats

Khapra beetle from the Mideast and Africa. Likes to hide in rice, lentils and other foods. Can ruin grain. Multiplies rapidly.

The Asian long-horned beetle. Highly destructive to trees and plants. Arrived on shipping pallets from China in 1997. Devastated thousands of maples and other hardwoods, mostly in the Northeast.

Asian gypsy moth. Voracious appetite for forest leaves. Attracted to lights of ships in port to lay eggs. After reaching next port, adults can fly beyond 25 miles to continue life cycle.

Emerald ash borer. Not a threat in their native lands but have no natural enemies here. Attacking ash trees.

Other

1904: Chestnut blight

1908: European corn borer

1915: Pink boll worm

1930: Dutch elm disease

1956: Witch weed

Disease threats

African swine fever

Bovine spongiform encephalopathy (mad cow disease)

Classical swine fever

Foot and mouth disease

You’d think Charleston was under attack, given the different types of invasive bugs caught trying to sneak in this year.

In April it was the notorious big-headed ant found crawling inside a pile of aluminum scrap on a ship from Costa Rica.

Known as Pheidole megacephala, it is among the world’s top 100 worst overseas invaders for its appetite for native plants, irrigation pipes, telephone cables and electrical wires.

The ant discovery was trumped last week when a rare type of tick was found in a crate of cotton work gloves coming from Pakistan.

It marked the first time the particular species has been found in a seaport anywhere in the U.S.

And while the critter can carry the West Nile virus, equally scary is that somehow the resilient, vampiric bug survived weeks in transit without a warm-blooded host to feed on.

Authorities say the uptick in these sorts of catches isn’t necessarily proof that the insect community is starting to revolt. Instead, they point to an increasingly active port, increased communication with other countries and a local inspection team better trained at finding a beetle in a haystack.

“I think we are improving our capabilities,” said Steve Switzer, who in Charleston leads a 12-person team of agricultural specialist agents with U.S. Customs and Border Protection. Seven days a week they are responsible for examining everything from vessel cargo to airport luggage and cruise ships.

How they get here

Part of their efforts include a better recognition of where the potential threats are coming from, including the military units and personnel returning from Iraq and Afghanistan. Some examples Switzer listed are foreign plant matter and insects that can hide in hard-to-reach spaces such as the grills of vehicles.

Even the return of a C-17 cargo jet could trigger an ecological upset, he said, if a seed gets lodged somewhere and later gets carried on the wind after touchdown, taking root as an invasive weed.

Inspectors already have found evidence of returning military armor carting in troublemakers. In one instance, a vehicle was cleaned up in Iraq, but it was left out in the open in Kuwait for a month.

When the vehicle arrived stateside, it carried a nest filled with eggs waiting to hatch from some unidentified species of Middle Eastern bird. The biggest fear is something coming in that has no known enemies. At least here.

On the tourism front, the cruise ship industry is a potential portal for trouble, Switzer said. He pointed to those woven palm hats tourists like to pick up in Mexico and the Caribbean; they’re conduits for the red palm mite.

And it’s not just luggage and cargo. A ship’s garbage likewise can pose hidden hitchhiker challenges, including mad cow disease.

“That could be an economy buster if that gets loose in our country,” said Robert Meyer, one of the Charleston port inspectors. Estimates peg the cost of searching, halting and reacting to invasive species trying to get into the U.S. at upwards of $134 billion a year.

Top bugs

Perhaps the most famous invader in Charleston history is the fire ant from South America. Originally thought to come through Mobile, Ala., around 1919, they quickly made their way to South Carolina, fed by the growing military and commercial Charleston waterfront. Other villains joined in, including the Japanese beetle and the Formosan termite.

Today’s most common threats are various. The gnat-sized Khapra beetle from the Mideast and Africa likes to hide in rice and grains, and can quickly overtake and devour stores.

Flying bugs, like the Asian gypsy moth, are a priority. They can travel as much as 25 miles away and establish residency.

Low-tech

Inspecting a cargo ship takes Switzer’s team about three hours. The work is minute. Wood pallets remain a common hiding place, as do cardboard boxes, rice shipments and rattan chairs. Droppings and sawdust piles from boring insects are clues.

Switzer’s team uses a variety of low-tech tools. One is a tube and jar assembly called an aspirator that he uses to suck up suspect insects safely into a vial to be scientifically identified later in a lab.

Another is 3-foot-long brass tube that can be plunged into rice and grains, scooping up samples that can be checked for eggs or live insects.

Infested cargo can be incinerated, sterilized or sent back. “Everything we’re getting in Charleston probably is coming from every other continent,” Switzer said.

Meanwhile, officials anticipate the need for greater diligence ahead once the Panama Canal widening is finished in 2015 and the Port of Charleston is deepened.

That means bigger ships, more diverse cargo and more potential threats.

Reach Schuyler Kropf at 937-5551.