A flight to combat pesky marsh mosquitoes with the insecticide naled has been rescheduled for Friday night.
Miami-Dade County mosquito control officials called off a Thursday application over the coast, from the Rickenbacker Causeway south and inland areas around Homestead, due to foul weather. Friday’s forecast for stormy weather could again cancel the flight, which must occur before dawn when marsh mosquitoes are active and will take four to five hours to complete.
Publicized just one day in advance, the flight quickly drew complaints from critics who oppose the use of naled, which is banned in Europe.
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In a letter to residents, South Miami Mayor Phil Stoddard warned families with infants or who are expecting a baby to leave areas being sprayed. South Miami bans the use of naled except to fight mosquitoes that carry diseases like the Aedes aegypti mosquito, which last year helped cause the first outbreak of the Zika virus in the continental U.S.
“If one of my family were pregnant or we had a newborn, I would relocate my family west of US-1 before nightfall tonight,” Stoddard wrote.
But Miami-Dade County officials say they follow Environmental Protection Agency guidelines for the safe use of naled. They cannot provide more advance notice because applications are dictated by the appearance of marsh mosquitoes tied to seasonal rain and the number of complaints they receive from residents.
Heavy rains this month have sent waves of the aggressive mosquitoes, which breed in mangroves and marshes but do not carry diseases, into neighborhoods triggering a flood of complaints, county officials said.
“We fly based on the need: the trap counts, the number of calls we get,” said spokeswoman Gayle Love. “So I can’t plan a month out for a salt marsh mosquito treatments because it happens when it happens and it happens when it rains.”
By contrast, Aedes aegypti mosquitoes are a year-round concern. That concern became more critical last year when they began transmitting Zika, which causes severe birth defects in babies and other illnesses in adults, in Wynwood, the Little River neighborhood and Miami Beach. In response, the county came up with a scheduled plan of attack, that included aerial and truck treatments posted well in advance on its web site. This year, the county has expanded its trapping and larviciding efforts and so far has not planned aerial spraying for those mosquitoes.
Naled has been used for decades to treat marsh mosquitoes, and largely went unnoticed beyond environmentalists and beekeepers because it kills pollinators. But with the Zike outbreak, it drew increased scrutiny when the Centers of Disease Prevention and Control called for its use.
Puerto Rico’s governor objected to using it on the island and critics have complained that too little is known about health effects or whether it actually succeeds at controlling the urban mosquitoes. Other organophosphates have been linked to developmental delays in children. A study published earlier this month found the babies of Chinese mothers exposed to naled developed slight problems with coordination at nine months old.
With heavy rain and thunderstorms again forecast for Friday, Love said the flight could be moved back from 8 p.m. to 10 p.m. and could depart even later as long as it’s completed before dawn.
“And if the weather isn’t going to be our friend, we will cancel the flight again,” she said.
Follow Jenny Staletovich on Twitter @jenstaletovich