Jennifer Castellon shook, tapped and blew on a box to shoo out more than 1,000 mosquitoes in a quiet, upscale Inland Empire neighborhood.

The insects had a job to do, and the pest scientist wanted every last one out.

Their task? Find lady mosquitoes and mate.

But these were no ordinary mosquitoes. Technicians had zapped the insects, all males, with radiation in a nearby lab to make them sterile. If they achieve their amorous quest, there will be fewer baby mosquitoes than there would be if nature ran its course. That means fewer mouths to feed — mouths that thirst for human blood.

“I believe, fingers crossed, that we can drop the population size,” said Solomon Birhanie, scientific director for the West Valley Mosquito and Vector Control District, which released the mosquitoes in several San Bernardino County neighborhoods this month.

Sterilized male Aedes mosquitoes are released from a box in Rancho Cucamonga.

(Myung J. Chun / Los Angeles Times)

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Controlling mosquitoes with mosquitoes

Mosquito control agencies in Southern California are desperate to tamp down an invasive mosquito — called Aedes aegypti — that has exploded in recent years. Itchy, unhappy residents are demanding it. And the mosquitoes known for fierce ankle biting aren’t just putting a damper on outdoor hangouts — they also spread disease.

The low-flying, day-biting mosquitoes can lay eggs in tiny water sources. A bottle cap is fair game. And they might lay a few, say, in a plant tray and others, perhaps, in a drain. Tackling the invaders isn’t easy when it can be hard to even locate all the reproduction spots. So public health agencies increasingly are trying to use the insects’ own biology against them by releasing sterilized males.

The West Valley district, which covers six cities in San Bernardino County, rolled out the first program of this kind in California last year. Now they’re expanding it. Next month, a vector district covering a large swath of Los Angeles County will launch its own pilot, followed by Orange County in the near future. Other districts are considering using the sterile insect technique, as the method is known, or watching early adopters closely.

On the plus side, it’s an approach that doesn’t rely on pesticides, which mosquitoes become resistant to, but it requires significant resources and triggers conspiracy theories.

“People are complaining that they can’t go into their backyard or barbecue in the summer,” Birhanie said at his Ontario lab. “So we needed something to strengthen our Aedes control.” Of particular concern is the Aedes aegypti, which love to bite people — often multiple times in rapid succession.

Releasing sterilized male insects to combat pests is a proven scientific technique, but using it to control invasive mosquitoes is relatively new.

Vector control experts often point to the success of a decades-long effort in California to fight Mediterranean fruit flies by dropping enormous quantities of sterile males from small planes. That program, run by the U.S. Department of Agriculture and the California Department of Food and Agriculture, costs about $16 million a year. That’s nearly four times West Valley’s annual budget.

So rather than try to tackle every nook and cranny of the district, encompassing roughly 650,000 residents, West Valley decided to use a more targeted approach. If a problem area reaches a certain threshold — over 50 mosquitoes counted in an overnight trap — it becomes a candidate.

And it’s still a big lift. About 10,000 mosquitoes are reared at a time at West Valley’s facility, about half of which will be males. The males are separated out, packed into cups and placed into an X-ray machine that looks like a small refrigerator. The sterilizing process isn’t that different from microwaving a frozen dinner. Zap them on a particular setting for four to five minutes and they’re good to go.

Equipment purchased for the program costs roughly $200,000, said Brian Reisinger, spokesperson for the district. He said it was too early to pin down a cost estimate for the program, which is expanding.

Some districts serving more people are going bigger.

The Greater Los Angeles County Vector Control District plans to unleash up to 60,000 mosquitoes a week in two neighborhoods in Sunland-Tujunga from mid-May through November.

With the sterile-insect program, “the biggest hurdle we’re up against really is scalability,” said Susanne Kluh, general manager of the L.A. County district, which is responsible for nearly 6 million residents across 36 cities.

In part to save money, Kluh’s district has partnered with the Orange County Mosquito and Vector Control District. They’re sharing equipment and collaborating on studies, but L.A. County’s releases will move forward first, said Brian Brannon, spokesperson for the O.C. district. Orange County expects to release its “ankle biter fighters,” as Brannon called them, in Mission Viejo this fall or next spring.

So far, the L.A. County district has shelled out about $255,000 for its pilot, while O.C. has spent around $160,000. It’s a relatively small portion of their annual budgets: L.A. at nearly $25 million and O.C. at $17 million. But the area they’re targeting is modest.

Mosquito control experts tout sterilization for being environmentally friendly because it doesn’t involve spraying chemicals, and it may have a longer-lasting effectiveness than pesticides. It can also be done now. Other methods involving genetically modified mosquitoes and ones infected with bacteria are stuck in an approval process that spans federal and state agencies. One technique, involving the bacteria Wolbachia was recently approved by the Environmental Protection Agency and is now heading to the California Department of Pesticide Regulation to review, said Jeremy Wittie, general manager for the Coachella Valley Mosquito and Vector Control District.

“Using pesticides or insecticides, resistance crops up very quickly,” said Nathan Grubaugh, associate professor of epidemiology at the Yale School of Public Health.

Vector control experts hope the fact that the sterilization technique doesn’t involve genetic modification will tamp down conspiracy theories that have cropped up around mosquito releases. One erroneous claim is that a Bill Gates-backed effort to release mosquitoes was tied to malaria cases in Florida and Texas. Reputable outlets debunked the conspiracy theory, pointing out that Gates’ foundation didn’t fund the Florida project and that the type of mosquito released (Aedes) does not transmit malaria.

To get ahead of concerns, districts carrying out the releases say they’ve engaged in extensive outreach and education campaigns. Residents’ desire to rid themselves of a scourge may overcome any anxieties.

“I think if you have the choice of getting eaten alive by ankle biters or having a DayGlo male X-rayed mosquito come by looking for a female to not have babies with, you’d probably go for the latter,” Brannon said. (“DayGlo” is a riff on the fluorescent pigment product of the same name — the sterilized mosquitoes were dusted with bright colors to help identify them.)

Sterilized male mosquitoes buzz around vector ecologist Jennifer Castellon as they are released in Rancho Cucamonga earlier this month.

(Myung J. Chun / Los Angeles Times)

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Disease at our doorstep

As the climate warms and some regions become wetter, dengue is expanding to areas it’s never been seen before — and surging in areas where it’s established. Florida has seen alarming spikes in the viral infection in recent years, and Brazil and Puerto Rico are currently battling severe outbreaks. While most people infected with dengue have no symptoms, it can cause severe body aches and fever and, in rare cases, death. Its alias, “breakbone fever,” provides a grim glimpse into what it can feel like.

In October of last year, the city of Pasadena announced the Golden State’s first documented locally transmitted case of dengue, describing it as “extremely rare” in a news release. That same month, a second case was confirmed in Long Beach. Local transmission means the patient hadn’t traveled to a region where dengue is common; they may have been bitten by a mosquito carrying the disease in their own neighborhood.

Surging dengue abroad means there’s more opportunity for travelers to bring it home. However, Grubaugh said it doesn’t seem that California is imminently poised for a “Florida-like situation,” where there were nearly 1,000 cases in 2022, including 60 that were locally acquired. Southern California in particular lacks heavy rainfall that mosquitoes like, he said. But some vector experts believe more locally acquired cases are inevitable.

Ale Macias releases sterilized male mosquitoes in Upland this month.

(Myung J. Chun / Los Angeles Times)

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Set them free

In mid-April, a caravan of staffers from the West Valley district traveled to five mosquito “hot spots” in Chino, Upland and Rancho Cucamonga — where data showed mosquito levels were particularly high — to release their first batches of sterilized male mosquitoes for the year. Peak Aedes season is months away, typically August to October in the district, and Birhanie said that’s the point. The goal is to force down the numbers to prevent an itchy tsunami later.

Males don’t bite, so the releases won’t lead to more inflamed welts. But residents might notice more insects in the air. Sterilized males released by West Valley will outnumber females in the wild by at least 100 to 1 to increase their chances of beating out unaltered males, spokeperson Reisinger said.

“They’re not going to be contributing to the biting pressure; they’re just going to be looking for love,” as Reisinger put it.

Eggs produced by a female after a romp with a sterile male don’t hatch. And female mosquitoes typically mate only once, meaning all her eggs are spoiled, so to speak. Vector experts say the process drives down the population over time.

Interestingly, the hot spots were fairly spread out across the district, indicative of the bloodsuckers’ widespread presence and adaptive nature. A picturesque foothills community in Upland was “especially interesting” because of its relatively high elevation, Birhanie said.

It was once inhabited primarily by another invasive mosquito that prefers colder, mountainous climates. Construction and deforestation in the area has literally paved the way for its humidity- and heat-loving brethren to move in.

Another neighborhood, in Rancho Cucamonga, posed a mystery. For the last two years, mosquito levels were consistently high. Door-to-door inspections, confoundingly, didn’t reveal the source.

“That’s one of the things about invasive Aedes mosquitoes — you can’t find them,” he said.

Next steps

Some vector control experts want to see a regional approach to sterile mosquito releases, similar to the state Medfly program.

Jason Farned, district manager for the San Gabriel Valley Mosquito and Vector Control District, believes a widespread effort “would be much more effective” and thinks that will come in time.

There are no talks underway to make it happen, and it’s not yet clear how it would work. Vector control agencies are set up to serve their local communities.

Fears of a bad mosquito year ahead are bubbling as the weather warms. Rain — which there was plenty of this spring — can quickly transform into real estate for mosquito reproduction.

When the swarms come, mosquito haters can take typical precautions: dump standing water and wear repellent. And they can root for the sterile males to get lucky.

For the last five months, it seemed very possible that a 46-year-old conversation had finally reached its end.

Since its launch from Kennedy Space Center on Sept. 5, 1977, NASA’s Voyager 1 spacecraft has diligently sent regular updates to Earth on the health of its systems and data collected from its onboard instruments.

But in November, the craft went quiet.

Voyager 1 is now some 15 billion miles away from Earth. Somewhere in the cold interstellar space between our sun and the closest stars, its flight data system stopped communicating with the part of the probe that allows it to send signals back to Earth. Engineers at the Jet Propulsion Laboratory in La Cañada Flintridge could tell that Voyager 1 was getting its messages, but nothing was coming back.

“We’re to the point where the hardware is starting to age,” said Linda Spilker, the project scientist for Voyager mission. “It’s like working on an antique car, from 15 billion miles away.”

Week after week, engineers sent troubleshooting commands to the spacecraft, each time patiently waiting the 45 hours it takes to get a response here on Earth — 22.5 hours traveling at the speed of light to reach the probe, and 22.5 hours back.

By March, the team had figured out that a memory chip that stored some of the flight data system’s software code had failed, turning the craft’s outgoing communications into gibberish.

A long-distance repair wasn’t possible. There wasn’t enough space anywhere in the system to shift the code in its entirety. So after manually reviewing the code line by line, engineers broke it up and tucked the pieces into the available slots of memory.

They sent a command to Voyager on Thursday. In the early morning hours Saturday, the team gathered around a conference table at JPL: laptops open, coffee and boxes of doughnuts in reach.

At 6:41 a.m., data from the craft showed up on their screens. The fix had worked.

“We went from very quiet and just waiting patiently to cheers and high-fives and big smiles and sighs of relief,” Spilker said. “I’m very happy to once again have a meaningful conversation with Voyager 1.”

Voyager 1 is one of two identical space probes. Voyager 2, launched two weeks before Voyager 1, is now about 13 billion miles from Earth, the two crafts’ trajectories having diverged somewhere around Saturn. (Voyager 2 continued its weekly communications uninterrupted during Voyager 1’s outage.)

They are the farthest-flung human-made objects in the universe, having traveled farther from their home planet than anything else this species has built. The task of keeping communications going grows harder with each passing day. Every 24 hours, Voyager 1 travels 912,000 miles farther away from us. As that distance grows, the signal becomes slower and weaker.

When the probe visited Jupiter in 1979, it was sending back data at a rate of 115.2 kilobits per second, Spilker said. Today, 45 years and more than 14 billion miles later, data comes back at a rate of 40 bits per second.

The team is cautiously optimistic that the probes will stay in contact for three more years, long enough to celebrate the mission’s 50th anniversary in 2027, Spilker said. They could conceivably last until the 2030s.

The conversation can’t last forever. Microscopic bits of silica keep clogging up the thrusters that keep the probes’ antennas pointed toward Earth, which could end communications. The power is running low. Eventually, the day will come when both Voyagers stop transmitting data to Earth, and the first part of their mission ends.

But on the day each craft goes quiet, they begin a new era, one that could potentially last far longer. Each probe is equipped with a metallic album cover containing a Golden Record, a gold-plated copper disk inscribed with sounds and images meant to describe the species that built the Voyagers and the planet they came from.

Erosion in space is negligible; the images could be readable for another billion years or more. Should any other intelligent life form encounter one of the Voyager probes and have a means of retrieving the data from the record, they will at the very least have a chance to figure out who sent them — even if our species is by that time long gone.

Gary Horejsi wrestled with the decision before him, knowing a life could be in his hands.

It was the third time that the woman had used drugs or alcohol since coming to CRI-Help, which runs a 135-bed residential facility in North Hollywood where people are treated for substance use disorder.

CRI-Help needed to be a safe place for people grappling with their addictions. In the past, others had been removed for less. Horejsi, the clinical director, had the final say on whether she should be discharged.

He perused her file on his computer. The woman was still trying, CRI-Help staffers told him. She hadn’t shared drugs with anyone. And if she were to leave, the risks of an overdose were graver than before.

Horejsi decided to let her stay.

“Things can’t be business as usual anymore,” their chief executive, Brandon Fernandez, later said at a CRI-Help staff meeting. If someone leaves treatment and resumes using drugs the same way they were before, “that could very well look like them dying.”

“So are we going to be willing to do something different?”

Fernandez had gathered CRI-Help staff in their North Hollywood conference room to talk about a Los Angeles County initiative that could reshape such decisions. It’s called Reaching the 95% — or R95 — and its goal is to engage with more people than the fraction of Angelenos already getting addiction treatment.

Across the country, more than 48 million people had a drug or alcohol use disorder, according to the latest results from the National Survey on Drug Use and Health. Only 13 million received treatment in the previous year. Among those who did not get treatment, roughly 95% said they did not think that they should.

Those numbers have collided with the grim toll of fentanyl, an especially potent opioid that has driven up deaths across the country. In Los Angeles County, the number of overdose deaths tied to fentanyl skyrocketed between 2016 and 2022, soaring from 109 to 1,910, according to a county report.

“We can’t just take the approach that we’ve been taking and kind of assume that everyone wants the services that we offer,” said Dr. Gary Tsai, director of the Substance Abuse Prevention and Control division at the L.A. County Department of Public Health. “That’s just not the reality.”

His department is trying to nudge addiction treatment facilities to change their approach, by offering financial incentives for those that meet R95 requirements. Among them: changing their rules to not automatically eject people who have a “lapse” of drug use.

Fernandez, whose organization is participating in R95, said abstinence is still its aspirational goal — and “we still have the ability to use our own clinical judgment on a case-by-case basis,” such as if people endanger other participants. But “we shouldn’t have blanket policies.”

To get R95 funding, they also cannot require people to be totally abstinent before being admitted. And under R95, treatment programs are also being encouraged to partner with syringe programs rooted in “harm reduction” — a philosophy focused on minimizing the harmful effects of drug use — to address the needs of people who may not want to enter or remain in treatment.

Some treatment providers “view us as the enemy instead of as allies,” said Soma Snakeoil, executive director of the Sidewalk Project, which provides Narcan spray to reverse overdoses and other services on L.A.’s Skid Row.

With R95, she said, “the biggest change is that harm reduction organizations and treatment providers are talking to each other in a way that was not happening before.”

Soma Snakeoil, executive director of the Sidewalk Project, gives first aid to a woman with an open wound on her foot last year in Los Angeles.

(Francine Orr / Los Angeles Times)

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The county is also prodding addiction treatment facilities to reexamine whether the way they operate could be turning people away, and look more closely at the “customer experience.” Tsai compared the situation to a restaurant drawing few customers: “How do we get more people in the door?”

Too often, “the drug dealers do a much better job of delivering their product to our patients than we do,” said Dr. Randolph Holmes, chair of government affairs for the California Society of Addiction Medicine.

When Johnny Guerrero decided to get off Skid Row and go into residential treatment in Los Angeles, he was initially turned away because he had arrived “late — maybe 10 minutes late,” the 35-year-old said.

He was only able to get in, he said, because the harm reduction worker who had taken him to the facility let him stay the night at her home, then brought him back the next morning. Even then, “there was so much paperwork. I was so dopesick. There was just hurdle after hurdle after hurdle.”

“They did not make it easy for an addict to get help,” Guerrero said.

In many cases, “the biggest barrier is just being able to get somebody on the phone” with a treatment provider, said Amanda Cowan, executive director of Community Health Project LA, which provides clean syringes and other services to people who use drugs. “When people are ready, they are ready in that moment.”

As of late March, roughly half of the addiction treatment providers that contract with L.A. County were on track to become “R95 Champions,” which could yield hundreds of thousands of dollars each in additional funding.

CRI-Help’s George T. Pfleger center in North Hollywood.

(Myung J. Chun / Los Angeles Times)

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To get those funds, they must turn in admissions and discharge policies that adhere to the R95 guidelines, as well as an “engagement policy.” They are also supposed to meet R95 requirements in one other area of their choice, which could include a “customer walkthrough” to see what might turn away clients.

CRI-Help, for instance, had decided to change how it asks newcomers to undergo a search. “The last thing we want to do is trigger someone’s trauma history and potentially have them walk out the door,” Fernandez said.

To ensure it was consistently done with sensitivity, CRI-Help drew up a script for staffers, emphasizing that consenting to a search would help maintain a safe facility. The hope is that “they feel they’re doing something as a part of a community — versus being forced to undergo something that’s uncomfortable.”

Staffers also tell them that if they have any drugs to hand over, “there’s not going to be any consequence, you can still come into treatment,” Fernandez said. “And if we find them on you, there still won’t be any negative consequences.”

The L.A. County push comes as state and federal officials have stressed the need for “low barrier” approaches to addiction care. Even cutting back on drug use can have positive results, researchers have found.

But some of the changes can be at odds with long-standing beliefs among treatment providers, many of whom got into the field after successfully battling their own addictions in programs firmly focused on abstinence.

Many in the field think “this is what works” because it did work for them, said Vitka Eisen, chief executive of HealthRight 360, another R95 participant. But “we’re the survivors, and we don’t talk to those who didn’t survive.”

Addiction researchers have long called to reexamine how people are treated for substance use disorders. More than a decade ago, a Columbia University center found that “much of what passes for ‘treatment’ of addiction bears little resemblance to the treatment of other health conditions.”

“This is inexcusable given decades of accumulated scientific evidence attesting to the fact that addiction is a brain disease,” the National Center on Addiction and Substance Abuse lamented in its report.

Experts argue that part of the problem is that addiction treatment has long been separated from the rest of the healthcare system. Richard Rawson, senior advisor to UCLA Integrated Substance Abuse Programs, said a major shift was the emergence of buprenorphine, a medication for opioid addiction that could be prescribed in ordinary clinics just like medicines for other chronic conditions.

But some Southern California treatment providers have viewed using buprenorphine and other such medications as short of sobriety, UC San Diego researchers found — even as California has ushered in requirements for licensed treatment facilities to either offer or help people access such medications.

Addiction is now much more widely understood as a medical condition, but “how much of that philosophy actually gets down to the level of the counselor?” Rawson said. “I think that’s still a work in progress.”

Tsai said a challenge in rolling out R95 is the ingrained idea that “you’re ready or not” for substance use treatment. But “we don’t actually treat any other health condition that way,” he said. “You don’t tell someone with diabetes, ‘Your blood sugar has to be completely under control, and then you’ll be ready for treatment.’”

In North Hollywood, counselors and other CRI-Help employees seated around the conference table studied the R95 goals printed on an L.A. County handout. One staffer said she was struggling with a specific statement, particularly for people in a residential setting: “Requiring abstinence is too high of a bar” for treatment.

Fernandez decided to share his own story. More than a decade ago, he was struggling with drug use, which had worsened after the death of his father. He was unemployed and didn’t have a stable place to live. When an outpatient counselor suggested residential treatment, he initially brushed off the suggestion.

CRI-Help’s staffers had questions and concerns about the changing approach to addiction treatment but ultimately seemed supportive.

(Myung J. Chun / Los Angeles Times)

He changed his mind after a “tough weekend,” but had no intention of abstaining from all drugs in the long term. Fernandez said he was nonetheless welcomed at CRI-Help: “Let’s just help you out for now.”

“I came here begrudgingly with a total attitude that I was going to continue smoking weed when I left treatment. I definitely wasn’t going to stop drinking,” even as he recognized that other things he was doing might be a problem, Fernandez told the CRI-Help employees.

Among those who had gone to treatment, he asked the group, “were you ready for total abstinence on Day One?”

“No. That wasn’t even my plan,” the same staffer replied with a rueful laugh.

Still, she and others were anxious about how they would keep everyone safe if clients used drugs, especially if they tried to bring them into the facility. “That worries me a little bit,” she said.

“It worries me too,” Fernandez said.

What preoccupies CRI-Help staff is how to balance the needs of people who have had a “lapse” into drug use with maintaining a safe environment for other clients grappling with addiction.

Horejsi said in an interview that whenever someone uses — even if they don’t share their drugs — “everyone knows, and that in itself does have an effect on people. Sometimes people will feel less safe.”

But Horejsi stressed to the group that “we’re already not discharging people for using” alone.

When people have relapsed, the North Hollywood center has monitored them one-on-one in its television room until staff are sure they are safe, then decided on their next steps. Some have ultimately been moved to another CRI-Help residential facility to continue getting treatment and have a “fresh start,” he said.

The clinical director also urged his co-workers to look back at the many changes CRI-Help had already undergone, such as starting to offer medication for addiction treatment. He reminded them that years ago, CRI-Help clients could be discharged if a doctor had given them an opioid pill at the hospital.

Mary Grayson, a longtime staff member at CRI-Help, spoke positively of the organizations changes over the years.

(Myung J. Chun / Los Angeles Times)

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“What about when we discharged people because they talked about getting — they glorified drugs?” said Mary Grayson, a longtime CRI-Help employee.

Leaning forward in her seat, Grayson reminded her co-workers that “CRI-Help is not what it was when I walked through those doors 25 years ago — thank God!”

It started with “two shacks on this property. Two raggedy shacks. And look at where we are now,” she said. “Without us changing and growing, we won’t be able to be who we are.”