Rubber tires have been good to the Aedes aegypti, the notorious Zika-spreading mosquito. Old tires are ubiquitous and offer a perfect spot for females to lay their eggs. The global tire trade has also fuelled the insect’s expansion into new areas around the world.

But now, a Canadian-led team wants to turn the tire against the mosquito — by refashioning it into an “ovillanta,” a simple $3.50 trap that just might offer a new weapon against diseases spread by the troublesome A. aegypti.

This includes not just Zika — which is now causing an epidemic and linked to serious birth defects and neurological disorders — but other important viruses like dengue, chikungunya, and yellow fever.

“That’s the beauty of the project; we are using recycled tires, which is the main source of these mosquitoes,” said project lead Gerardo Ulibarri, a chemistry professor with Sudbury’s Laurentian University. He added that studies have shown that discarded tires represent nearly 30 per cent of breeding sites used by the A. aegypti.

“I think this exemplifies very nicely that we can reduce the amount of mosquitoes that bite through an ecological and cheap, efficient method.”

On Thursday, Ulibarri and his team released a preliminary study of their ovillanta on the open science publishing site F1000Research.

While the paper has not yet been peer reviewed, Ulibarri and his team report they were able to collect nearly seven times more mosquito eggs using the ovillanta than standard traps. The study, conducted last year in Sayaxche, Guatemala, was funded with help from the Canadian government and Grand Challenges Canada.

Ulibarri’s ovillanta is actually modelled after an “ovitrap” that he first developed at Laurentian University (to tackle West Nile-carrying mosquitoes) and previously tested in Mexico (to fight dengue).

But when Ulibarri wanted to test his trap in Guatemala, he needed a low-cost version — and enlisted his brother, an engineer, who helped design the rubber tire prototype.

The hope behind the ovillanta is this: that by collecting and destroying mosquito larvae, communities can kill the insect’s next generation and reduce exposure to the diseases they carry.

The trap is designed to lure A. aegypti mosquitoes away from other breeding sites. It involves two 50-centimetre chunks of rubber tire, fitted together like a mouth, with a lower cavity that collects water that the mosquito needs to hatch its eggs.

In Guatemala, Ulibarri also added an “attractant” that he invented. It uses milk-based natural compounds to lure the A. aegypti.

The water from the ovillanta can also be reused as a natural attractant. According to Ulibarri, egg-laying mosquitoes release natural pheromones, which accumulate and concentrate in the water over time.

“The mosquitoes, when they are looking for a place to lay their eggs — it’s called the oviposition site — they will be attracted by certain chemicals that indicate a good place for babies to be born,” he explains. “For instance, they will not lay their eggs in a fish pond because they know as soon as the larvae are born, the fish is going to eat them.”

During the 10-month study period in Guatemala, Ulibarri and his team collected and destroyed 181,336 eggs in households using the ovillanta. Households that used standard traps were only able to collect 27,053 — a statistically significant difference, according to Ulibarri’s paper.

He and his team made another interesting observation. “What we found was that in this city of Sayaxche, Guatemala, there was no dengue,” Ulibarri said, adding that only three cases were detected during the study period, all of which were imported from other areas.

Ulibarri cautions that this was not a scientific observation and disease surveillance in this area is lacking; there is no proof the ovillantas caused the reduction in cases.

But the observation is promising enough that Ulibarri will continue testing and validating the ovillanta. His goal is to eventually distribute the traps to communities that need them, or produce kits containing the necessary parts for people to make them on their own.

Ulibarri stresses, however, that the ovillanta must be complemented by efforts to engage local communities. In Sayaxche, people are leery of mosquito-control programs that use pesticides, which they associate with dead chickens and sick children.

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Ulibarri and his team spent five months educating local health workers — who were surprisingly misinformed on basic matters of disease vector control — and engaging local leaders, while also teaching people how to reduce mosquitoes around their homes.

This includes eliminating other breeding sites that might compete with the ovillanta — everything from discarded pop cans to flower pots, all objects where water can pool.

“It’s like destroying the cheap hotels and just leaving the mosquitoes the best hotels,” Ulibarri jokes.

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