Canadian Team’s Low-Cost, Eco-Friendly Mosquito Trap Holds Hope For Curbing Zika And Other Tropical Viruses
A team of both Canadian and Mexican researchers has developed a low-cost, environmentally friendly trap that captures the eggs of the mosquito genus that spreads viruses such as dengue, chikungunya, and Zika, according to a new study in F1000 Research’s Zika and Arbovirus Research Channel.
The article, which is awaiting peer review, describes how over the course of 10 months the researchers, working in a remote area of Guatemala, were able to fashion traps from old tires that successfully captured and destroyed tens of thousands of eggs laid by female mosquitoes of the Aedes genus.
The system includes a trap called an “ovillanta” created from two 50 cm sections of an old car tire fashioned into a mouth-like shape with a fluid release valve at the bottom. Inside the lower tire cavity a milk-based, non-toxic solution lures mosquitoes. Females lay eggs on a paper strip and are later destroyed using fire or ethanol.
The milky solution, which collects mosquito pheromones, concentrates as it is recycled, and the ovillanta becomes even more attractive to the mosquitoes.
Researchers found the rubber ovillanta significantly more effective at attracting the Aedes mosquito than standard traps made from 1-litre buckets. During the study, the team collected and destroyed over 18,100 Aedes eggs per month using 84 ovillantas in seven neighbourhoods in the town of Sayaxché, almost seven times the roughly 2,700 eggs collected monthly using 84 standard traps in the same study areas.
The team said that there were no new cases of dengue reported as originating in the ovillanta study test area during that 10-month period, a community that would normally anticipate two or three dozen cases in that timeframe.
The project was financed by the Canadian government’s Grand Challenges Canada and led by Gerardo Ulibarri of Laurentian University with collaborators Angel Betanzos and Mireya Betanzos of the National Institute of Public Health of Mexico. Guatemala’s Ministry of Health assisted in the research.
Targeting mosquito eggs using the ovillanta, Dr. Ulibarri says, is one third as expensive as trying to destroy larvae in natural ponds and only 20% the cost of targeting adult insects with pesticides, which also harm bats, dragonflies, and the mosquitoes’ other natural predators.
“We decided to use recycled tires—partly because tires already represent up to 29% of the breeding sites chosen by the Aedes aegypti mosquitoes, partly because tires are a universally affordable instrument in low-resource settings, and partly because giving old tires a new use creates an opportunity to clean up the local environment,” said Dr. Ulibarri.
The Aedes genus of mosquito—the principal genus that transmits Zika, dengue, chikungunya, and yellow fever viruses—has proven extremely difficult to control using other strategies, according to the World Health Organization.
A female, with a natural lifespan of up to three months, can start to reproduce in one week. Pesticide-resistance, dwindling resources, and an increase in mosquito-friendly environments have thwarted traditional methods of controlling the insect’s rapid spread.