Most pests you battle every day aren’t originally from here.
“I think it’s pretty safe to say that most of our worst pests are invasive species,” said Dr. Dan Strickman, national program leader for the USDA’s Agricultural Research Service.
According to a 2004 Cornell University report, more than 4,500 foreign arthropod species reside in the continental U.S. and Hawaii, and the number is rising.
Invasive plants, animals, insects and organisms — approximately 50,000 species — cost the United States about $120 billion a year, said the report.
With the increased movement of people, equipment and commodities around the world, exotic pests challenge our borders daily.
“Studies have shown that the more trading partners you have and the more materials that flow into and out of your country, the more likely it is that you will suffer from invasive species problems,” said Dr. Mark Hoddle, director of the Center for Invasive Species Research at University of California, Riverside.
After 9/11, many agricultural scientists responsible for stopping invasive species at ports of entry were reassigned to anti-terrorism duties, reported the Associated Press. An analysis of border protection records showed the number of pest cases intercepted at U.S. ports fell from more than 81,200 in 2002 to fewer than 58,500 in 2006.
The live plant trade is a virtual pest highway. Almost 70 percent of the most damaging non-native forest insects and diseases currently afflicting U.S. forests arrived on imported live plants, according to the National Center for Ecological Analysis and Synthesis at the University of California, Santa Barbara.
Even pleasure boaters are guilty. Dr. Rudolf Scheffrahn at the University of Florida has seen dozens of yachts and sailboats pull into port carrying termite species from all over the world. “The potential is there for them to be introduced to the U.S.” because the crafts aren’t inspected for these pests.
“You can blame it all on humans,” he said. It would take a thousand years for termites to move from South Florida to Atlanta, but at 70 miles per hour on the turnpike they can be there in 10 hours.
Hot spots. Climate determines whether invasives can survive once they get here, and with many coming from tropical locales like South Asia and the Caribbean, the hotter and more humid, the better. While Texas and the Gulf Coast get their share of pest introductions, South Florida is ground zero.
“Florida’s a mess,” said University of Georgia Entomologist Dr. Dan Suiter, who grew up near West Palm Beach.
Almost every month, a new exotic arthropod is detected in the state, reported the Florida Department of Agriculture and Consumer Services.
Stopping the Threat
There was good news and bad news when Craig Sansig heard back from the Pennsylvania Bureau of Health upon submitting pictures of a specimen for identification earlier this year.
Sansig, service director and staff entomologist, Viking Termite and Pest Control, Bridgewater, N.J., had been contacted by Viking Technician Nicholas Malcolm in June to identify a beetle. The technician had come across the specimen while treating a commercial facility in Pennsylvania — a maintenance worker had luckily saved the beetle for inspection after it had been flying around the facility and hit him on the head, Sansig said.
“At first I thought it was an Asian longhorned beetle,” Sansig said. The Asian longhorned beetle is a wood-boring beetle, imported from Asia, which could have been devastating to trees in the area if it had spread and reproduced. “The rings on the antenna looked similar. But the rest of it, the pattern didn’t match. I couldn’t find a match, so now I was getting concerned. I knew this company imports things from Asia.”
After getting in touch with the USDA Animal and Plant Health Inspection Service (APHIS) and the Pennsylvania Bureau of Plant Health, Sansig received a foreboding call back.
“He said, ‘I’ve got good news and bad news,’” Sansig said. “Good news was, it was not an Asian longhorn. The bad news was, they didn’t know what it was, and it could be worse.”
A few days later, Sansig arrived at the facility where the mystery beetle had been found, along with backup. “Entomologists from the USDA, Pennsylvania Bureau of Plant Health, carrying cameras and sampling equipment. I thought, ‘Great, my customer is going to love this.’ I wasn’t expecting such a show of force.”
The crew began inspecting products and pallets inside the facility, searching for beetle damage, and found three pallets that had been heavily damaged by the beetle. On one, they found live larvae, Sansig said.
The mystery beetle turned out to be a yellow spotted longhorn beetle (Psacothea hilaris) — native of Southeast Asia and never discovered in Pennsylvania. The beetle causes serious damage to ficus, fig, holly and mulberry trees. Sansig said several trees across the street from the facility in question were found to have damage, and those trees were chopped down, chipped and burned to ensure that the threatening pests could not spread.
The sample of the yellow spotted longhorn beetle was taken by the USDA and was submitted to the Smithsonian for cataloguing, as no sample of the beetle is in their collection, Sansig said. He credited the diligence of the staff at Viking Termite and Pest Control for stopping this invasive pest from potentially becoming disastrous. — Bill Delaney
“We have about 20 pest ants here in Florida and 19 of them are introduced species,” said Scheffrahn. The only native pest ant is the Florida carpenter ant.
Insects aren’t the only worry. Peter Eldridge, president of Apex Pest Control in Rockledge., Fla., near Miami, bought a pistol that uses shotgun shells to ward off anacondas, a native of South America. He has contracts to kill invasive weeds that clog lakes, ponds and drainage ditches for municipalities and golf courses. “I don’t feel much like wrestling with a 15-foot snake,” he said.
Pathogens are another concern. A species doesn’t have to become established to transmit pathogens, said Dr. Ken Linthicum, director of the USDA-ARS Center for Medical, Agricultural & Veterinary Entomology in Gainesville, Fla.
Scientists don’t know how West Nile virus got here, but it moved across the country. “That could happen very easily with another pathogen that comes in with an invasive species,” said Linthicum. He’s particularly worried about Rift Valley fever from Africa. Some of our mosquito species can transmit it, he said.
Sometimes invasive pests can establish populations in odd places due to manmade micro-climates.
In Palm Springs, Calif., red imported fire ants have infested golf courses due to irrigation, said Linthicum. Aedes aegypti mosquitos, usually found along the Gulf Coast, are entrenched in Phoenix, Ariz., for the same reason. Asian tiger mosquitoes have been found in the San Gabriel Valley near Los Angeles. “It’s not an area where you’d normally expect to find that mosquito,” he said.
Even termites do well in micro climates. A botanical garden in Berlin, Germany, has a “huge infestation” of the Asian subterranean termite, Coptotermes gestroi, said Dr. Brian Forschler of the University of Georgia.
He recently identified this pest in shipping materials in Michigan. Though tropical, the species might have done well in a northern area had it found a heated, manmade structure. That’s how our native Eastern subterranean termite, Reticulitermes flavipes, has survived in seven Canadian cities, he said.
Pests of concern. Ants and mosquitos have experts on edge.
Invasive ants spread rapidly with human help and have traits that make them highly successful in new environments, said Terminix International Technical Services Director Stoy Hedges in the April issue of PCT. These include multiple queens, unicolonial and interspecific behavior, colony dispersal by budding and fission, and small workers that can handle many tasks.
Forty-four percent of pest management professionals surveyed by the Professional Pest Management Association and Dr. Laurel Hansen of Spokane Falls Community College said the rise in ant infestations are due to new ant species.
Certain mosquito species are “ripe for invasion to the United States,” said Strickman. Topping his list is Culex tritaeniorhynchus, a rice field mosquito of East Asia and vector of Japanese encephalitis, a virus that “would change life as we know it.”
Malaria could become a problem in the United States again if Anopheles albimanus, found in the Caribbean and South America, were to become established. And Aedes notoscriptus, a container-breeding mosquito from Australia that likes warm, dry climates, could be a new day-biting nuisance in areas like California.
The Asian tiger mosquito, already entrenched in the United States, has been linked to an African Chikungunya fever pandemic in Italy. “It certainly could happen here,” said Linthicum.
Most Wanted List
We don’t have enough space to list every established invasive pest in the U.S., so here are our top five picks. These pests thrive in temperate climates, cover broad geographic areas and affect many people.
Argentine Ant (Linepithema humile)
Red Imported Fire Ant (Solenopsis invicta)
Formosan Subterranean Termite (Coptotermes formosanus)
Asian Tiger Mosquito (Aedes albopictus)
Asian Lady Beetles (Harmonia axyridis)
Stay vigilant. Strickman urged pest control professionals to be alert to new species so “there’s at least a hope of containing the problem before it gets too bad,” he said.
In the mid-1980s, the Asian tiger mosquito was localized in Houston, he said. It was probably there for a few years before it was recognized, and by then the pest was well established.
Forschler identified Asian subterranean termites in Michigan only because attentive Orkin employees sent him the specimens. This “illustrates the value of being vigilant” and the important role PMPs play in eradicating potential infestations that could become more of a problem.
He recounted how 10 Formosan termite infestations tied to railroad ties from New Orleans were identified and eradicated in Atlanta in 1989. But another infestation from the ties found in 2004 went untreated at the apartment property management’s insistence.
“Now we have an infestation that’s been there 20-plus years,” said Forschler. “I don’t think we’ll be able to eradicate them.” In 50 years, this may cause infestations in a large part of Atlanta, he said.
If a pest shows up in a place or behaves in a way that you wouldn’t expect, take the time to make sure it is what you think it is, advised National Pest Management Association Technical Director Jim Fredericks.
At Bug Out Service in Jacksonville, Fla., company policy requires pests that look the least bit different be identified with the microscope at the branch office, said Technical Director Linda Prentice.
If technicians still are unsure, they can send the specimen to Prentice, who works closely with the Duval County Cooperative Extension agent, University of Florida entomologists, Florida Department of Agriculture and Consumer Services, and Florida Pest Management Association, as needed. It’s not a one-man job. “It’s a real team effort,” she said.
This team was essential when Caribbean crazy ants hit the scene, and the industry needed help educating customers and finding ways to suppress them, she explained.
Collect specimens, information. When a pest piques your curiosity, collect multiple live specimens and note the exact location, number observed and weather conditions, said Wayne Grush, entomologist and owner of Green Gator Pest Control in Houston.
Describe where you found the pests — in a nest, under rocks — and your observations on behavior, added Hoddle. Take digital photos, maybe with a coin or finger for scale, and send everything to a cooperative extension office or university researcher in a crush-proof container. Insects don’t survive the U.S. postal service in an envelope, he said.
At the port in Brunswick, Ga., Suiter has collected about 40 ant species. One is likely new to science. “It’s never been described before,” he said. Two other specimens are new records for the state of Georgia. “If you see something weird, collect it and get it identified,” he urged. “It could be the beginning of something real big.”
Know what invasive pests are problems in other regions and prepare your business to deal with them, advised Forschler.
“You’ve got to pay attention,” said Mike Rogers, president of Killingsworth Environmental in Indian Trail, N.C. He stays up-to-date by attending industry meetings and listening to peers.
Universities, manufacturers and distributors offer tremendous resources to help identify and mitigate invasive species, added Grush.
On the Watch List
The USDA carefully monitors for these pests, which could have a devastating impact should they become established here. Visit www.pctonline.com and click on “online extras” for an article on “recent fugitives,” pests that have been introduced to the U.S. recently.
Khapra Beetle (Trogoderma granarium Everts)
Tropical African Bont Tick (Amblyomma variegatum)
View USDA’s watch list at www.invasivespeciesinfo.gov/animals/notestablished.shtml.
The California Center for Invasive Species Research
University of Georgia Center for Invasive Species and Ecosystem Health
University of Florida Pest Alert
Florida Invasive Species Partnership
Having a bigger perspective helps, too, said Ravi Sachdeva, CEO and entomologist of American Pest Management in Manhattan, Kan. He identified an emerald ash borer, a forest pest that has killed more than 20 million ash trees in the Great Lakes region, at a customer’s home. The pest emerged from wood transported to make furniture.
“We were able to identify it because of the information I had read in various professional publications,” said Sachdeva. Although his company doesn’t treat for emerald ash borer, it helps to come across as a “knowledgeable, informed person to a potential or existing customer. It’s a matter of being informed and being informative.”
PMPs in California may want to get familiar with invasive tree pests like gold spotted oak borers and red palm weevils. The citrus psyillid, often found on backyard citrus trees, is causing major crop losses in Florida, Texas and California.
Professionals who are aware of and prepare for invasive species will hold a competitive edge over competitors who choose to ignore these problems, said Grush.
The author is a frequent contributor to PCT magazine. She can be reached at firstname.lastname@example.org.
Illustration by Matthew Laznicka