Brevard Mosquito Control District: History and What It Is

Brevard County’s Mosquito Control program, created as the Brevard County Mosquito Control District by a 1937 special act of the Florida Legislature (chapter 18437), is the agency that fights mosquitoes in Brevard County, Florida. County government lists Mosquito Control among its departments, and its current pages are on the county website, brevardfl.gov.

What is the Brevard Mosquito Control District?

A product of a special act. The Florida Senate’s index of special and local laws lists, under Brevard County, a “mosquito control district” with creation in 1937 and a run of later acts: regulations in 1957, group insurance for employees in 1963, bonus limits and uniform funds in 1967, purchasing rules from 1967 through 1970, and two acts in 1971. Cocoa sits on the Indian River Lagoon in Brevard County, the county named in that law.

The date puts Brevard among the early districts. The same index lists the Indian River Mosquito Control District with creation in 1925, the year of the Florida land boom, and a 1937 act on a mosquito control district in Pinellas County, the year of Brevard’s. Cocoa, founded on the Indian River Lagoon, lies in the county the act names.

The name has survived. When Brevard County and the “Brevard County Mosquito Control District” appealed an Order of Taking to Florida’s Fifth District Court of Appeal in 2004, that was the district’s name in the case caption.

Map of Canaveral National Seashore and Merritt Island National Wildlife Refuge on the Florida coast, with Titusville at lower left, Cocoa near the bottom edge, the Indian River and Mosquito Lagoon in blue, and Black Point Wildlife Drive marked inside the green refuge area. — The Merritt Island refuge on the 1993 federal visitor map, with Black Point Wildlife Drive inside the green refuge area, Titusville at left and Cocoa along the bottom. *National Park Service and U.S. Fish and Wildlife Service, Library of Congress. Public domain.*

Why did Brevard need a mosquito district?

Because the marsh bred them by the million. A federal brochure on Merritt Island says that until the late 1950s the marshes nurtured saltmarsh mosquitoes, which at times could produce a million mosquitoes per square yard in one day. The salt marshes and mangrove forests along Florida’s east coast have, historically, been prolific breeders, according to the University of Florida’s Florida Medical Entomology Laboratory, and the lagoon shore was no exception.

Organized control along the Indian River Lagoon began in the mid-1920s, by the UF/IFAS account, about three decades after the 1894-95 freeze. The first tool was the shovel. Crews hand-dug hundreds of miles of parallel ditches to drain the breeding ground. The method was abandoned because the ditches needed constant maintenance and, with so little tide on this coast, did not work well against mosquitoes or sandflies.

How did the district fight mosquitoes?

With whatever the decade offered. In the 1930s an experiment showed that impounding a marsh, diking it and flooding it, could cut breeding at the source. The experiment ended when water losses to evaporation and seepage grew too large. By the early 1940s the emphasis had shifted to DDT and other pesticides, and by the early 1950s mosquito control on the lagoon relied almost entirely on chemicals.

A man in a cap and work clothes stands at the edge of a wooded bayou and sprays a mist from a hand-held applicator out over the water. — A worker sprays DDT along a wooded waterway in 1958, in a photograph from the U.S. malaria eradication program. It is not a Brevard picture, but it shows the method that dominated control in the 1950s. *Centers for Disease Control and Prevention, Public Health Image Library 4684. Public domain.*

It could not last. By the mid-1950s pesticide resistance was becoming a problem and worries about the chemicals’ effects on the environment had surfaced. In 1954 Brevard County renewed its emphasis on source reduction and impounding, and the other counties along the lagoon followed. The IFAS publication counts more than 7,900 acres of wetlands impounded along the lagoon by 1959 and, ultimately, about 40,000 acres, all before the mid-1970s. It does not split those totals by county.

What do the impoundments do?

They flood the marsh in mosquito season. Salt-marsh mosquitoes will not lay eggs on standing water. They lay on moist soil, and the eggs hatch when tides or rain cover it. Keep the marsh flooded from roughly May to October and the females have nowhere to lay, which, as IFAS puts it, eliminates production from the area without pesticides.

The federal brochure for the Canaveral seashore and the Merritt Island refuge, published in 1993, describes the result in its own words: because saltmarsh mosquitoes do not lay eggs in fresh water, “engineers divided 69,000 acres of marsh into walled impoundments” to control water levels, salinity and mosquitoes. That is not the IFAS figure of about 40,000 acres for the whole lagoon, and the two accounts differ. The brochure gives no county or date for its total. A separate refuge brochure says Black Point Wildlife Drive, a six-mile auto route, follows a series of mosquito control dikes, and that management of one impoundment is a cooperative venture between the Brevard Mosquito Control District and the refuge.

Several blue-winged teal standing and resting at the edge of dark water, with a green plant in the foreground. — Blue-winged teal at Merritt Island National Wildlife Refuge, where the refuge says its impoundments provide food for wintering waterfowl. Photo submitted by Mary Beth Seibert to the Indian River Lagoon National Scenic Byway (Federal Highway Administration, Scenic Byways Program), National Archives and Records Administration, via Wikimedia Commons. Public domain.

Did the impoundments have a cost?

Yes. The University of Florida extension publication says research since the 1970s has shown that impounding can have severe environmental impacts on the marshes and the adjoining estuary: degraded water quality, habitat cut off from sport and commercial fish at the stages of life when they need it, lost marsh vegetation, possible harm to seagrasses and a break in the flow of nutrients between marsh and lagoon. Some impoundments were flooded far above the level needed, which killed the vegetation inside.

The cost also reached the courts. In Brevard County v. Blasky, decided by the Fifth District Court of Appeal on April 30, 2004, Brevard County and the Brevard County Mosquito Control District appealed an Order of Taking concluding that the district had taken the Blaskys’ real property by inverse condemnation.

The federal brochure puts the other side of the ledger plainly: the new environment attracted new residents, and today it is common to see waterfowl, alligators, otters and wading birds such as snowy egrets, white ibises and great blue herons.

Two snowy egrets with black bills and yellow feet wading in shallow dark water beside a branch with green leaves. — Snowy egrets wading at Black Point Wildlife Drive in April 2012, the kind of wading birds the 1993 federal brochure says the impounded marsh attracted. *Photograph by Rusty Clark, Flickr, via Wikimedia Commons. CC BY 2.0.*

Where do I find Brevard’s spray schedule today?

On the county’s own pages. This site tells the history, and the agency tells you when and where it is spraying. Look for Mosquito Control on the Brevard County website, brevardfl.gov. More of Cocoa’s story is on the history page.