Woodinville-based SpringStar has $3 million in grants to produce and test low-tech mosquito traps for Puerto Rico and other places hit by the Zika-carrying insects.

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Seattle has spawned several high-tech efforts to combat Zika and other mosquito-borne diseases, from research on vaccines and drugs to the Bill & Melinda Gates Foundation’s vision of genetically engineering mosquitoes or infecting them with microscopic bugs to block viral transmission.

But there’s also a low-tech battle under way, led in part by a local company that specializes in simple devices to trap and kill insects, usually without pesticides.

Woodinville-based SpringStar has received more than $3 million in federal grants to refine, test and produce two types of mosquito traps, one of which consists of little more than a bucket and sticky paper.

“We kill the mosquitoes, not the environment,” said company President Michael Banfield.

The bucket traps have already been deployed and tested in small communities in Puerto Rico, where Zika is raging. The U.S. Centers for Disease Control and Prevention is preparing to mount a much larger demonstration in the island territory.

“We don’t think that this trap is the end-all, be-all solution to control Zika,” said CDC epidemiologist Tyler Sharp, who’s based in Puerto Rico. “We do think it’s one approach that households and communities could employ to reduce their risk.”

Though its formal name is the Autocidal Gravid Ovitrap, the device could simply be called a death trap for Aedes mosquitoes, the type that spread Zika, dengue fever and other diseases, Banfield said.

Females in search of a place to lay their eggs are lured into the trap by the scent of water and hay, which mimics the aroma of a scummy pond or stagnant puddle. Once inside, a screen blocks the insects’ access to the water, and they are ensnared in a tube of glue-coated paper.

The trap is easy to maintain, requiring only an occasional refill and a new sticky tube.

“You can set it and forget it,” Sharp said.

The system was developed by CDC scientists, who cobbled together paint buckets and other scavenged parts for early prototypes. SpringStar refined the design and developed mass-production techniques.

Part of the challenge was finding the right kind of glue for the sticky surface. One version actually repelled the mosquitoes instead of attracting them, Sharp said. “Very small modifications to the design of the trap can have a big impact on whether it works or not.”

In field trials in small villages in Puerto Rico, deploying three traps per household was enough to reduce the mosquito population by more than 80 percent. At the same time, the number of people infected with chikungunya, a virus transmitted by the same types of mosquitoes that spread the Zika virus, fell by 50 percent.

The CDC is conducting similar trials to see if the risk of Zika infection can also be lowered by deploying the traps in targeted areas.

“We’re certain these traps can kill mosquitoes,” said Karl Malamud-Roam, manager of the Public Health Pesticides Program at Rutgers University. “What we’re not sure of is if we can kill enough of them to be below the threshold of disease transmission.”

The emergence of Zika, which is now being transmitted by mosquitoes in parts of Miami, underscores some of the problems with traditional approaches to mosquito control, said Malamud-Roam, who has collaborated with SpringStar.

Aedes mosquitoes thrive in urban environments, hiding in houses and laying eggs in discarded water bottles and inside tires. Conventional spraying doesn’t work well in that setting. And with only a few pesticides approved for use, more and more mosquitoes are developing resistance.

“The era of broadcast pesticides for mosquito control, as the only tool in town, is coming to an end,” Malamud-Roam said. “There’s increasingly a sense that we need a much wider toolbox.”

For example, the second type of trap being tested at SpringStar contains a pesticide that kills mosquito larvae — but deploys it in a very targeted way.

Female mosquitoes are lured inside, but instead of getting stuck they are dusted with the pesticide as they exit the trap, explained Emilie Bess, the company’s research liaison. When the females lay their eggs, they also deposit a small amount of the pesticide, which kills all larvae in the pond or puddle before they mature.

Michael Banfield and his wife, Jane, launched SpringStar almost 20 years ago in their garage. Today the company occupies a 45,000-square-foot site, where workers manufacture nontoxic traps for yellow jackets, fruit flies, bedbugs and a host of other insect pests. Their biggest seller is a pheromone-laced sticky trap for moths.

The company is preparing to open a facility in Puerto Rico to manufacture up to 15,000 mosquito bucket traps a day. The goal is to keep the price at about $15 per trap for use in the developing world, Banfield said.

Though targeted at Aedes mosquitoes, the traps also work against many of the species common in the Pacific Northwest, he added. But the devices won’t be available here commercially until next year.