Texas A&M AgriLife entomologists: Floating fire ants, insect pests among flood hazards

Writer: Gabriel Saldana, 956-408-5040, [email protected]
Contact: Dr. Paul Nester, 713-274-0950, [email protected]
Dr. Mike Merchant, 972-952-9204, [email protected]

HOUSTON – Fire ants, as their colonies begin to flood, can join feet or tarsi to form water rafts, and they are more aggressive once in the floating formation, according to Texas A&M AgriLife Extension Service entomologists. But other insect pests can also pose human threats in flood conditions, they said.

Dr. Paul Nester, AgriLife Extension entomologist, Houston, and Dr. Mike Merchant, AgriLife Extension urban entomologist, Dallas, encourage those affected by flooding to stay prepared and aware of pests, especially when it comes to mosquitoes, floating fire ant colonies and bedbugs.

The warning comes after Hurricane Harvey drenched much of southeastern Texas, dropping more than 50 inches of rain in some places and flooding significant portions of metropolitan Houston.

In Texas, the biggest human threat from mosquitoes continues to be West Nile virus from night-flying pests, Merchant said. He pointed out that Zika virus also remains a risk, though a minor one. But nuisance mosquitoes, like the saltmarsh mosquito, not considered especially important for carrying human disease, will be most noticeable in the weeks after water subsides.

“Heavy rains actually reduce some mosquito breeding sites, especially those of the southern house mosquito, which is our primary carrier of West Nile virus,” Merchant said. “But as waters subside and puddles dry up and stagnate, these mosquitoes will return after a few weeks.”

Merchant recommends anyone conducting hurricane cleanup and repairs keep mosquito repellent handy at all times, especially at night.

Meanwhile, Nester said fire ant colonies floating through floodwaters are dangerous, as they are alive and will “explode” upon contact with an object or person, engulfing the subject and stinging it relentlessly in an effort to protect their queen at the center of the formation. He said people should take precautions to avoid run-ins with floating colony “mats” and should remain aware of what objects are floating near and toward them in floodwaters.

“Dress appropriately when working in floodwater,” he said. “Cuffed gloves, rain gear, and rubber boots help prevent the ants from reaching the skin. If they do, they will bite and sting. Remove the ants by rubbing them off.”

Go to https://agrilifetoday.tamu.edu/wp-content/uploads/2017/08/ENTO_006.pdf to see Nester’s short guide on fire ant protection in flood conditions.

While some face challenges from the rising water, Merchant has other advice for displaced Texans living in temporary shelters: be on alert for bedbugs. The pest, while not a major problem in most evacuation centers, has a way of showing up when many people converge in close quarters, Merchant said.

“The most important thing is that shelters are aware of the potential for bedbug problems and have a plan for how to respond,” he said.

He said shelter managers should prepare by knowing what bedbugs look like, inspecting sleeping quarters regularly and employing a reputable pest control company to deal with infestations as necessary.

Go to http://citybugs.tamu.edu/ for comprehensive information on insect pests.