Wondering what life was like here before the Florida Legislature established the Indian River Mosquito Control District 100 years ago?
Ask your neighbors who live along the southern tier of the barrier island, where many of them have been going buggy amid swarms of mosquitoes that have driven them indoors for much of the past two months.
“It’s bad,” said Sid Sutton, who lives on Island Drive in the St. Christopher Harbor neighborhood, located south of The Moorings and west of State Road A1A. “If you open your front door, they’re in your house.
“You don’t see people walking down the street, especially at night,” he added. “Most days, you can’t go outside until 1 or 2 in the afternoon, when it’s hot and still. But in the morning or late afternoon, forget it. Nobody’s doing anything outside for long.
“You can see the mosquitoes – they’re everywhere.”
In fact, Sutton said longtime neighborhood homeowners have told him they had never experienced a mosquito infestation of this magnitude and for this duration, adding that the wife of one neighbor has grown so weary of the situation that she wants to move.
Even spray-on bug repellent provides only temporary relief.
St. Christopher Harbor isn’t alone: Sutton said he has heard from friends who are enduring the same mosquito-spawned torment in other neighborhoods in the vicinity.
One of Sutton’s buddies, local attorney Colin Lloyd, said he has lived in Ocean Oaks East for 13 years and “this is, by far, the worst the mosquitoes have ever been.”
As of Monday, however, there was little the county’s Mosquito Control District could do to alleviate the problem – because, as the agency’s executive director said last week, “Mother Nature is not cooperating.”
According to Sherry Burroughs, who overseas the district’s operations, she and her team are confronting “atypical challenges,” precipitated largely by the extended periods of hot, dry and breezy conditions that have dominated the Vero Beach area’s weather in recent weeks.
“Our most effective source-reduction methods have been taken off the table,” she said, adding that coastal areas, particularly from the Wabasso Causeway to the St. Lucie County line, are “experiencing the most significant impacts.”
Drought conditions that offer only sporadic rainfall and prolonged low tide levels are especially troublesome.
The low tide levels during the current spring-into-summer mosquito breeding season have prevented the district from flooding the impounded marshes along the Indian River Lagoon.
By using culverts and pumps to control water levels in the marshes, the district’s mission is to create conditions that are less hospitable for breeding. Flooding the impoundment submerges the exposed mud where mosquitoes lay their eggs, thus preventing hatching and development.
However, Burroughs said, those areas typically require a minimum tide of 25 inches to allow for effective flooding, and the current minimums have dropped to just four inches.
“As a result, most of the marshes remain dry, though small, scattered pockets of standing water persist,” she explained. “These pockets are capable of producing substantial numbers of mosquitoes and are inaccessible to field inspectors, native predators and aerial application methods.”
Aerial application methods?
Burroughs was referring to the low-flying yellow airplane that has become part of Vero Beach folklore and, more recently, the deployment of drones.
The district uses the yellow airplane to drop larvicide over salt marshes and mosquito-breeding grounds along the lagoon – areas that otherwise would be inaccessible.
Mosquitoes breed in standing water and wet soil, which means the airplane must hit its targets for the source-reduction effort to be effective.
“Dropping the product on dry land doesn’t really help, and until the conditions change, there’s not enough water and wet ground to make aerial treatment viable,” Burroughs said. “The area we can treat is too small.”
That’s because, she added, the yellow plane requires a minimum treatment block of 250 acres for the trip to be efficient and cost-effective.
Burroughs said the district’s most recent use of the yellow airplane was on June 5 – after the targeted area received 2.75 inches of rainfall – and covered 637 acres along the shores of the lagoon.
No further aerial treatments have been scheduled, she added, “due to lack of contiguous treatable acreage and unsuitable environmental conditions.”
The district has used drones to target smaller and more-isolated areas, Burroughs said, but the remote aircraft’s capacity is limited to a maximum of only 70 acres per day.
Also, Florida law sets line-of-sight requirements that restrict access in certain marsh zones.
Working within those constraints, Burroughs said, the district has increased its reliance on “truck-mounted, ultra-low-volume” spraying to control the adult mosquito population.
The breezy conditions, however, “have further complicated our response,” she added, because the spray cannot be used safely and effectively if winds exceed 10 mph.
While early evening is when the spraying would be most effective, Burrough said the nightly breezes have forced the district to move them to 3:30 a.m.
“Evening winds have been especially problematic, limiting our ability to treat during peak mosquito-activity periods,” she said. “As a result, we have shifted some application to early morning hours, when wind conditions are more favorable, because we don’t want to push our treatments into non-targeted areas.
“We’re also rotating product types to avoid resistance and improve results.”
In addition, the district has implemented what Burroughs called “thermal fogging” in select, high-activity zones – particularly along the edges of marshes and spoil islands – to target adult mosquitoes emerging from nearby breeding sites.
“St. Lucie County is having the same issues,” she said, “and those mosquitoes can fly up to 25 miles.”
Thermal fogging involves using a machine to heat a liquid insecticide solution, turning it into a dense fog that can be quickly dispersed over large areas to target adult mosquitoes.
The fine droplets can penetrate foliage and other hidden places, and the fog is designed to remain airborne long enough to kill mosquitoes on contact.
Burroughs said the district has used the fog only once in the last two years, but she added that one longtime employee told her the current mosquito infestation marks only the third time in 30 years the problem has reached this level.
“Unless the conditions change, we’ve pivoted to thermal fog and early morning trucks,” she said.
As of Friday, Vero Beach had received only 11.7 inches of rain in 2025. That’s more than eight inches below normal.
But even if we start getting the summer rains we expect, the problem could worsen – at least initially.
“With more rain comes more difficulty, because the conditions are so dry now that it will create puddles and mud, which creates a better breeding ground for mosquitoes,” Burroughs said. “It’s a constant battle.”
In the meantime, she said, the district continues to closely monitor tide cycles, rainfall and ground conditions, then adjust their daily operations to “maintain control as effectively and efficiently as the conditions allow.”
Until the conditions change, however, Burroughs advised residents in the affected area to avoid being outdoors during high-activity time for mosquitoes – especially the early evening hours – and protect themselves by wearing long sleeves and long pants when they do leave the house.
She also recommended they use insect repellent and, if desired, submit service requests via email (irmcd@irmcd.org) or the district’s website (irmosquito.com).
“We’re doing all we can do, when we can do it,” Burroughs said. “But it’s not a typical season, and we have only so many tools in our toolbox.”
That leaves our neighbors along the island’s southern tier with two options:
Pray for rain. Or bug out.
