THE NEXT STRUCTURAL PEST PROBLEM IN ALEXANDRIA

THE NEXT STRUCTURAL PEST PROBLEM

While no one can predict what insect species may invade and thrive in Australia, experts Proven Pest Control Alexandria talked to have some guesses.

So what’s the next big invasive pest for structural pest control? It’s impossible to say, said experts.

“Before the brown marmorated stink bug and kudzu bug got here, nobody had ever heard of them,” said Dan Suiter, entomologist, University of Georgia. “In terms of trying to predict what might be, you just can’t.”

Many exotic species already reside in the United States. The Southeast, alone, has 67 documented species of exotic ants, noted expert Joe MacGown, Mississippi Entomological Museum.

Pests already in the United States but living “under the radar and waiting for the scale to tip in their favor” may be the next big challenge for pest management professionals, said Ed Vargo, entomologist, Texas A&M University.

Consider the Asian needle ant, first documented in the 1930s, and the dark rover ant, identified here in the 1950s. In the last 10 to 15 years, their populations — as well as those of other exotic species — have exploded.

Why? Some entomologists believe climate change may play a role. “If you get a 3 degree change in the average temperature per year it’s possible that we could have fire ants in St. Louis,” said Bob Vander Meer, research leader at the U.S. Department of Agriculture’s Agricultural Research Service in Gainesville, Fla.

Others think we accidently may have helped exotics adapt and thrive. Mike Rust, entomologist at University of California-Riverside, cited the shift from single-queen to multiple-queen ant colonies. Baiting for red imported fire ants might kill off 80 percent of the colony, so having multiple queens increases the chance of the colony’s survival, he explained. Over time, “we’ve selected for colonies with multiple queens,” he said.

The mixing of once-geographically isolated species may create new invasive problems. When you take species out of their natural areas and you throw them together in a new environment “all kinds of things can happen,” said Vargo.

Consider the aggressive red imported fire ant and cool-tolerant black imported fire ant of South America: The two distinct species, which never mixed in their native land, have not only mated in the U.S., but their offspring can reproduce. This may be helping the hybrid ant expand its range further north, said experts.

Similarly, scientists at the University of Florida reported intermating between Formosan and Asian subterranean termites. More research is needed to determine if hybrid colonies survive in the field and if offspring can reproduce; even so, they could grow to twice the size of parental colonies, reported entomologists. “There are all kinds of implications for long-lived, bigger colonies,” said Suiter. “If the population gets bigger they cover more area and have greater food needs.”

Entomologists don’t expect a “new” invasive to impact structural pest control nationwide, but they do believe regions of the country, where the habitat is most suitable to invaders, will have serious issues. The most devastating invasive pests, they said, will affect forests, turf and agriculture.

Here are some alien invaders that have experts worried:

Not Yet Established

Khapra Beetle

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Khapra Beetle (Trogoderma granarium)

According to the USDA, this beetle is one of the world’s most destructive pests of stored grain products and seeds. It can survive without food for long periods, requires little moisture, hides in tiny cracks and crevices, and is relatively resistant to insecticides and fumigants. Previous U.S. detections have required massive, long-term and costly control and eradication efforts. It prefers hot, dry environments, like in Arizona, California, Kansas, New Mexico, Oklahoma and Texas, but can survive in storage facilities protected from cold, reported the agency. A khapra beetle infestation could shut down U.S. grain exports, which would have a massive economic impact, said Stephen Sapp, public affairs officer for U.S. Customs and Border Protection.

Yellow Crazy Ant (Anoplolepis gracilis)

Yellow Crazy Ant

www.antweb.org

“One of the top worst invasive ants in the world,” this pest has devastated island ecosystems, said MacGown. The ants swarm in huge numbers and spray formic acid on unwanted competitors, including nesting birds. “Vertebrate, invertebrate animals are at risk,” said MacGown. Eradication efforts are underway on Oahu and Johnston Island. The ant, which likely hails from West Africa, has not been reported on the continental U.S., but could survive in South Florida, said USDA’s Vander Meer. “We don’t want it,” warned MacGown.

A Growing Problem

Asian Subterranean Termite

Pest and Diseases Image Library

Asian Subterranean Termite (Coptotermes gestroi)

This termite “will be for us in South Florida and the Keys what C. formosanus did to New Orleans,” said Bill Kern, entomologist, University of Florida. The termite was first detected in Miami in 1996. Today, it is found along the “whole southeast coast of Florida,” he said. The tropical pest is expected to stay in South Florida, however experts said the hybridization of C. gestroi and the Formosan termite, as reported by UF researchers, could expand its range. “The establishment of hybrid termite populations is expected to result in dramatically increased damage to structures in the near future,” said Thomas Chouvenc, an assistant researcher who worked on the study with termite expert Nan-Yao Su, University of Florida.

Tawny Crazy Ant (Nylanderia fulva)

Tawny Crazy Ant

Joe A. MacGown

An “Argentine ant on steroids,” the tawny crazy ant can blanket an area with millions of workers, said MacGown. Infestations are a “really traumatic experience for homeowners,” noted Vander Meer. Experts said the pest likely will have the same range as fire ants. In some places it is displacing fire ants, said McGown. Moving colonies by accident is easy. Suiter thinks the pests got to Georgia in campers and trailers heading north from Florida as nests were found near exits on I-95. Vander Meer said USDA researchers are working on widespread control methods using water-soluble baits different from those used for fire ants. MacGown urged researchers to study the pest’s impact on ground-nesting birds.

Asian Needle Ant (Pacnyla chinensis)

Asian Needle Ant

©bugwood.org

This ant has been “around for a long time, but it never achieved notoriety until more recently,” said Vander Meer. “Something has released it in term of population growth because now there are many more incidents of people complaining about the Asian needle ant,” he said. It has been documented in Alabama, Mississippi, Florida, Georgia, the Carolinas, Tennessee, Virginia, Connecticut, New York, Washington and Wisconsin. “I don’t know enough about those populations to say whether they’re thriving and coming back next year but the fact they’ve been able to find them in these areas is pretty impressive,” said MacGown of the more northern sites. With an expected range similar to fire ants, the pest is known to displace other species like the Argentine ant and packs a painful, lingering sting that can cause allergic reactions.

Dark Rover Ant (Brachymyrmex patagonicus Mayr)

Dark Rover Ant

©bugwood.org

This tiny ant from Argentina is “spreading pretty fast” in the U.S., said MacGown. In California, they once were rarely found; “now, when doing collections in urban areas in southern and central California, they’re everywhere,” said Rust. The ant doesn’t sting or bite, but poses problems for commercial clients like hospitals and food processing facilities. Small, multiple-queen colonies fill tiny little gaps – in pine cones, dune vegetation, cinder blocks – so they’re difficult to control. They also reside along with more aggressive ant species.

European Fire Ant (Myrmica rubra)

European Fire Ant

©bugwood.org

Adapted to colder weather and packing a potent sting, this ant is a problem in the Northeast and Pacific Northwest and is spreading, said Vander Meer. Its potential range in North America could span the southern-most inland part of Florida to the north of Hudson Bay in Canada, stated an online University of Florida publication. The ant seems to prefer humid places along the coasts, but experts believe it is capable of establishing colonies inland.

Wild Pigs (Sus scrofa)

Wild Pigs

©bugwood.org

According to the USDA, feral pigs cause $1.5 billion in annual damage and control costs and have expanded their range from 17 to 39 states in 30 years. Once a forest and agricultural problem, pigs are moving into suburban and urban areas causing traffic accidents and thousands of dollars of damage for individual homeowners, according to Billy Higginbotham, wildlife expert at Texas A&M University. Mike Botha, president of Sandwich Isle Pest Solutions in Pearl City, Hawaii, traps an average of 30 pigs a month (more than 500 so far); the largest was 350 pounds. They breed at an incredible rate and are very smart; if you pick off one or two you’ll never get enough to control populations because they won’t make the same mistake twice, he said. A best-guess estimate of the wild pig population in the U.S. is 4 to 8 million, said Higginbotham.

TOP ALL-TIME INVASIVES

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According to the Invasive Species Specialist Group, a global network of scientific and policy experts on invasive species, the 100 all-time worst pests on a worldwide scale include some familiar to pest management professionals:

• Argentine ant (Linepithema humile)
• Asian tiger mosquito (Aedes albopictus)
• Big-headed ant (Pheidolemegacephala)
• Common malaria mosquito (Anophelesquadrimaculatus)
• Common yellow jacket (Vespula vulgaris)
• Feral pig (Sus scrofa)
• Formosan termite (Coptotermesformosanus)
• Khapra beetle (Trogoderma granarium)
• House mouse (Mus musculus)
• Little fire ant (Wasmannia auropunctata)
• Red imported fire ant (Solenopsis invicta)
• Roof rat (Rattus rattus)
• Yellow crazy ant (Anoplolepis gracilipes)

See the entire list by visiting Proven Pest Control Alexandria.