MIAMI — One recent sunny morning, Chalmers Vasquez, Miami-Dade County's mosquito control manager, peered into a rain-filled Miller High Life bottle in a weedy back yard.
"This is very dangerous, this situation here," he said, surveying a glistening pile of dozens more bottles at his feet.
A few steps away, his fears were confirmed. There, in a junked toilet lying on its side, he found in a small pool of rainwater the squiggling larvae of an Aedes aegypti mosquito, the type that is spreading the Zika virus and fear of grave birth defects throughout Latin America and the Caribbean.
Summer is coming, and the Aedes aegypti will soon be buzzing around its usual haunts in the United States — mostly in the South and Southwest. But it is already here in South Florida, hatching from kiddie pools and rain-catching flowerpots, recycling containers and bottle caps. Scientists do not believe that the United States will have a runaway Zika epidemic, but most agree that mosquitoes here will eventually acquire it and that they could start infecting people, leading to local flare-ups.
"A woman could get bitten by a mosquito and have a child with a terrible malformation — and that could happen in Florida or Texas or Arizona, or anywhere this mosquito is," said Dr. Thomas R. Frieden, director of the Centers for Disease Control and Prevention. "We don't think the numbers will be large," he said, "but the impact could be very large."
Stopping Zika's spread, he and other public health experts say, will require muscular mosquito control across a broad swath of the United States. But the quality of services varies wildly.
Some of the weakest spots for mosquito control are in places where the Zika mosquito regularly appears — Mississippi, Alabama, Georgia and the Carolinas, and along the Texas coast — largely because they lack the tax base to pay for it, said Joseph Conlon, a retired Navy entomologist who is a technical adviser to the American Mosquito Control Association.
If there were ever a place most at risk for homegrown Zika, it is Florida, the state with the largest number of imported Zika cases in the continental United States — 74 reported at last count. And Miami-Dade, the largest port of entry into the United States from the biggest countries in Latin America, according to federal statistics, is the county in Florida with the most reported cases, 32.
Despite its importance, Miami-Dade County, population 2.8 million, spends just $1.8 million on mosquito control, enough for a staff of 17, of whom 12 are inspectors. In contrast, Lee County, home to Fort Myers and 660,000 people, spends $16 million a year and has a staff of 88.
"It is odd that there's not more money, considering we are such a global entry point," said Whitney A. Qualls, a vector biologist at the University of Miami.
Mosquito control in the United States is a crazy quilt of jurisdictions that includes powerful independent districts with their own taxing authority and threadbare county health, environment or public works departments.
Scrambling to gauge mosquito control preparedness, the CDC recently produced a map of mosquito districts known to exist with troubling blank spots. And some places that were colored in as having districts said "district" was too grand a word.
"I had to kind of laugh," said Paul Ettestad of the New Mexico Department of Health, remarking on the fact that his state appeared to be completely covered. Most of what was colored in, he said, "was a guy in the county who drives a snow plow in the winter and a sprayer in the summer."
And with local public health budgets still shrunken since the recession of 2008 and President Barack Obama's $1.8 billion Zika funding request stalled in Congress, health officials are starting to worry.
That concern pervaded a Zika Action Plan Summit meeting of several hundred local health officials organized by the CDC on Friday in Atlanta. Their problems were different, but all had one in common: too little money.
"There is a broad pattern of decline, and that kind of places us in a handicapped position to start this race," said E. Oscar Alleyne, the senior adviser for public health programs at the National Association of County and City Health Officials, which has calculated that local health departments — where some mosquito control departments reside — have lost about 12 percent of their staffs since 2008.
Traditional spraying from trucks and planes is mostly useless against this mosquito, a stealthy urban dweller. Instead, beating it back will require a lot of mosquito workers like Vasquez dumping over a lot of water containers in a lot of back yards.
Vasquez, a soft-spoken man with closely cropped hair and a fondness for bugs, set out with his small team of mosquito inspectors one recent morning, armed with chemical larvae killer and turkey basters to suck up larvae-infested water.
The Aedes aegypti mosquito rarely flies more than a few blocks, so their mission was to destroy breeding grounds near the houses of people suspected to have been infected with the Zika virus. The team knows that as more Zika-infected travelers come to South Florida, the risk rises that a healthy mosquito will bite a sick person, pick up the virus and infect healthy people.
The first house with a suspected Zika case was in a scruffy neighborhood in North Miami, canary yellow with a for-sale sign out front. Next door, a young man dressed in blue shorts and a striped T-shirt was arguing in Spanish with Pedro Castellanos, one of the inspectors. A white cat shot out the front door. Castellanos marched over to a water-filled cat litter box in the front yard and poured it out.
He handed the man a warning that said he had to clean up his yard or pay a fine. The department rarely enforces the fines, but Castellanos said he handed out warnings anyway, "to scare them" and improve the chances they will comply.
At the next house, a Haitian immigrant was raking palm tree trimmings, and Castellanos, who has a sixth sense for the unlikely places mosquitoes breed, was immediately on alert.
"Sir, do you collect rainwater?" Castellanos asked politely. The man nodded yes and walked him around to his back yard, where a tall blue plastic container stood in the shade.
"I don't mind if you do this," Castellanos said, "but put a screen on top."
Risk lurks in rich neighborhoods, too, for example in bromeliad plants favored by landscapers. Their stiff fronds are perfect receptacles for rainwater.
"Look at that!" Vasquez said, pointing to a cluster of the plants, their spiky stalks sticking up like rock-star hair in front of a cream-colored ranch house. "Perfect Aedes aegypti habitat."
When pressed, Vasquez acknowledged that handling a serious flare-up would require asking for additional funding.
Qualls, of the University of Miami, put it more bluntly: "Miami-Dade has great people, but their budget is not enough to handle a Zika crisis."
If that happens, Conlon, the adviser to the American Mosquito Control Association, said the county, and others like it, would probably have to hire private contractors. (Vasquez said he was making such arrangements.) Frieden of the CDC said the budget request to Congress included money for that.
So far in Miami, resources have been enough. But summer is coming and Vasquez is on high alert. He stopped at one house that looked abandoned only to have the homeowner, Robert Hoak, emerge, blinking into the sun. Hoak said he was so preoccupied tending his terminally ill wife that his mostly empty swimming pool had turned into a mosquito breeding ground.
"Do whatever you've got to do, guys," he shouted as Vasquez climbed down into the pool to sprinkle some larvae killer in the green water.