Winning the Mosquito Wars

Winning the Mosquito Wars

It’s not easy keeping the pesky pests at bay, but abatement officers are a dedicated lot undeterred by slogging through marshland and the dangers of West Nile virus.

If only Joseph Huston’s job were as easy as finding a needle in a haystack—then he might be able to spend a few waking hours away from work each week. But after nearly a quarter century spent tracking tiny, winged ectoparasites throughout cracks, crevices, saltwater marshes, and neglected water containers from Berkeley through the Tri-Valley, the grizzled mosquito hunter knows better.

Huston’s work schedule usually looks like this: mosquito larvae abatement during the winter, followed by trying to contain West Nile virus each summer. West Nile infection rates go up during long, dry periods, and 2014 was the worst year in a decade for West Nile infections in California. On this particular day, Huston was concerned about reports of West Nile warning signs in the Livermore area, which he said tend to be worse during dry periods. The deadly West Nile virus obviously riles up the public and typically sends Huston and his tiny staff of field technicians into all-hands-on-deck mode, not to mention overtime. This particular week was especially hellish for Huston, who started each workday at around 7 a.m. in Hayward and worked well into the night overseeing anti-mosquito spraying in Livermore in response to finding there an abnormally high number of dead birds infected with West Nile virus.

“We’re a small organization, but that’s part of what makes us who we are,” Huston said.

Huston is the field supervisor of the Alameda County Mosquito Abatement District, a small agency headquartered on Hayward’s industrial back roads and equipped with a staff of 18 and an annual budget of about $3.5 million. It’s one of more than 70 similar agencies located throughout California that keep the state’s metropolitan areas habitable for people, in this case by putting a damper on the hundreds of thousands of potential mosquito-breeding sites in Alameda County. If not for the mosquito abatement agency, there’d be tens of millions or more mosquitoes here, some with a range as large as 20 miles or farther, Huston said. That’s enough to travel from the estuary to the Oakland hills, making countless lives miserable along the way. Mosquito abatement has been so effective that the pests have largely flown under the radar. Most residents don’t even know the agency exists, even though they pay for it with a series of voter-passed and ad valorem property taxes.

“If a lot of people don’t know about us, that means we’re doing our job,” Bruce Kirkpatrick, district entomologist with Alameda County Mosquito Abatement District, said. “But it’s kind of a quandary that we’re in, because a lot of the time, when people find mosquitoes, they don’t know we exist and don’t know what to do.”


Mosquito abatement workers have to be equipped with a lot of skills. Huston and most of his colleagues have a bachelor’s degree in some form of marine biology or environmental studies, and many also hold master’s degrees or doctorates. They have to be familiar with the Bay Area’s more than 20 different species of mosquitoes and be able to recognize telltale-warning signs of West Nile infestations, like finding a crop of dead crows. On top of that, they need to be willing to walk thigh-deep in marshland, carrying multi-gallon spray containers of Methoprene, a chemical that mimics a juvenile mosquito’s hormone and prevents the growth of larvae. Workers have to travel through cemeteries with a tank, dousing each gravestone urn, where water can accumulate. Sometimes they traverse the worst neighborhoods in the Bay Area with the intention of searching residents’ backyards for mosquito ponds. Huston recalled one occasion where a complaint took him to East Oakland, where he discovered the “culprit” mosquito-breeding house happened to be full of crack addicts and prostitutes. He finally found, and killed, hundreds of mosquito larvae at the bottom of a sewage line that had been disconnected and was dumping human waste into the basement.

With that in mind, mosquito abatement techs need to know when to pull the “I’m-going-to-fine-you-$1,000-a-day-if-you-don’t-let-me-kill-mosquitoes-in-your-neglected-pool” card and when to play the “I’ll-turn-my-head-the-other-way-if-you’re-growing pot-if-you-just-let-me-set-up-some-mosquito-fish-in-your-pond” card as they look out for their own safety. The consequences of failure could mean thousands more citizens of the county with welts on their bodies, or an increase in West Nile deaths among the elderly. West Nile is a virus common in birds and is usually detected from a patch of dead birds. Symptoms for humans include headache, fever, and respiratory difficulty. It can deadly for the elderly people and youngsters, though usually it is not. Californians hear about West Nile and precautions annually.

“Basically, we’re here for this,” says Huston, gesturing toward a group of kids playing soccer on a grass field in Oakland, as he straddles one of tens of thousands of storm drains, checking for stagnant water buildup—a potential “Holiday Inn” for mosquito larvae. “All these people here, I don’t want them to get West Nile virus. I want them to be able to come out here and play without being chewed up by mosquitoes.”

Alameda County is home to 22 different types of mosquitoes, each with varying potentials to spread disease and each with a different mating cycle, habitat, and range circumference. The most common, Culex pipiens, the common house mosquito, is a year-round mosquito that typically flies into homes and bites people at night. Then there are salt marsh mosquitoes, like the Aedes dorsalis, which bites during the day and is capable of traveling well into the residential areas throughout the East Bay. Mosquitoes from the culex genus, which breed in neglected ponds or pools, tend to be known carriers of West Nile. Many times, in order for mosquito abatement techs to successfully combat a given infestation, they need to collected mosquito samples and send them to a lab for testing, so they can know what species they’re dealing with. If they find pond-dwelling mosquitoes in the Oakland hills, for instance, they know they need to find someone with a neglected pond and install “mosquito fish.” Whereas, if they discover salt marsh mosquitoes in the Oakland hills, they can surmise that one of the marsh technicians might have missed a spot.

“There are salt marshes that ring the edges of the bay, and these marshes produce super-aggressive mosquitoes,” Kirkpatrick says. “There’s a summer version, and a winter version. They’re extremely aggressive mosquitoes, and they can be produced in extremely high numbers. And most people don’t know that these mosquitoes exist.”

Most folks probably don’t notice the salt marshes either, except maybe in their peripheral view while driving, but Huston seems to view them more as a ticking time bomb, each capable of unleashing millions of parasites with the potential to bite people in multiple cities. There used to be a time, prior to mosquito abatement’s formation, when that was part of life in the bay. In fact, Alameda County-area mosquitoes successfully slowed Bay Area development for decades.

“A hundred years ago, there were parts of the Bay Area where you couldn’t go outside at night after a certain time of the year; mosquitoes were just too bad,” Kirkpatrick said. “The reason mosquito abatement districts were formed was because real estate developers wanted to sell this beautiful property, and they lobbied the politicians to create abatement districts.”

That was back in the 1920s and ’30s, and originally, the Alameda County Mosquito Abatement District’s only real focus was to keep mosquitoes out of those marshes—and make way for the postwar housing boom of the 1950s. Of course, the district’s success ironically paved the way for thousands more mosquito infestations; with the construction of new infrastructure came a virtually endless number of potential mosquito havens. So since then, the mosquito abatement has largely focused on working with the public to deal with the man-made mosquito havens that are prevalent. The work is impossibly difficult—imagine trying to find a mosquito that has a five-mile range and can reproduce in just a couple gallons of stagnant water, sometimes even less than that.

“There are hundreds of thousands of households in this county, and we cannot go check every single one. I couldn’t do that if I had ten times as many people as I do,” Huston said. “We rely on people to check their own backyards. Remember, if it holds water, sooner or later it will breed mosquitos. We try and stress that.”


There are tens of thousands of water traps that need to be checked year-round, even during the dry season, including drought periods like the one California is currently experiencing. Discarded bottles or other litter accumulate inside these water traps and dam them up, perfect mosquito breeding grounds. “I had Berkeley, and we have a map with little red dots for every single storm drain entry point,” said mosquito abatement vector biologist Michelle Izumizaki. “We hire seasonal workers to go around the field and systemically spray the catch basins.”

Additionally, Huston and his field technicians have to worry about regularly checking their own mosquito traps, which they place to essentially bag and tag mosquitoes, and to study them.

“Mosquitos are naturally attracted to CO2, which is produced when you exhale—kind of like how sharks are attracted to blood,” Huston said. “So we’ll set up a CO2 trap with a little fan on it; the mosquitos can get in, but you can’t get out. Then we anesthetize them and identify them to see what species are active.”

In recent years, mosquito fighters have even taken aerial photographs of the county, to look for green pools, which can breed thousands of mosquitoes in just a few weeks. It’s a painstaking task to visually examine hundreds of thousands of households for green pools, so some inevitably fall through the cracks, Izumizaki said. And it’s virtually impossible for abatement personnel to have a handle on all the potential stagnant water containers in peoples’ backyards. That’s why they stress that county residents have to be vigilante as well, and remember, if it holds water, it will eventually breed mosquitoes.

But Huston does what he can. On this day, he drives through neighborhoods by the Oakland Coliseum, inspecting water traps that have been known to hold stagnant water in the past and making sure there are no new mosquito colonies brewing. He works until well past dusk, knowing full well he’s going to have to get up around 5 a.m. the next day to head toward Livermore for an update on the West Nile situation. More often than not, Huston works overtime, but he usually doesn’t log it, he said.

“Our typical policy is that, if anyone in the county calls, we’ll respond within 24 hours, and being the size we are, that’s difficult,” he said. “But we can’t pass the buck to anybody else. If we didn’t do certain areas, you could draw a five-mile circle around it, and know that area will be just full of mosquitoes.”

Alameda County residents who encounter mosquitoes can get a little ammo from their friends at Mosquito Abatement: anti-mosquito fish. And even better, the abatement folks deliver, to anybody in Alameda County, for free, if requested. For more information, call 510-783-7744 or visit

Nate Gartrell is a freelance writer who lives in Oakland.

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