Campinas University Develops Cheap, Biodegradable Formula to Fight Dengue Mosquito

RIO DE JANEIRO, BRAZIL – Researchers from the Faculty of Food Engineering (FEA) of the State University of Campinas (UNICAMP) have developed a biodegradable particle, made from corn starch and thyme essential oil, able to kill the larvae of the Aedes aegypti mosquito.

Thyme oil is a lethal larvicide agent for the insect, a carrier of diseases such as dengue, zika, and chikungunya.

Through the combination of the two compounds, a controlled release particle of larvicide has been developed for small water volumes, such as those in plant pots, tires, bottles and rubble, that often serve as a breeding ground for the Aedes aegypti.

“We were able to achieve a particle that behaves exactly like mosquito eggs. While the environment is dry, it remains inert and keeps the active agent protected. As soon as it comes into contact with water, it begins to expand to enable the release of the larvicide,” explains Professor Ana Silvia Prata, the study’s coordinator.

According to her, after three days, when the eggs hatch and the larval phase begins, the particle starts to release lethal amounts of the active ingredient into the water.

Corn starch ensures the strategy

The cornstarch particle base serves the purpose of enveloping the thyme oil, which is slowly released when coming into contact with water.

“While the water is in the same concentration as the oil, it will not be released. It has dried and soaked again so that it will release more oil,” explained the teacher.

The particle against the mosquito that carries dengue is able to eliminate mosquito larvae more than once while in contact with water.

“We designed the particle so that it would remain dry and be durable. We didn’t perform regular testing, but even after a year of production, it worked,” said Ana Silvia.

“We believe that the particle can have a very long shelf life while dry. Regarding its use, we believe that it can last more than five rain cycles”, said the study coordinator.

Non-toxic particle

The FEA professor explained that the concentration of thyme essential oil in the particle is very low and therefore would not affect animal and human health. “The rate is well below the toxicity limit for an animal or a child who may inadvertently ingest it.”

Sustainable and inexpensive

Ana Silvia explained that the particle developed by the FEA is inexpensive and could be produced on a large scale for distribution among the population. In her opinion, this would be a complementary measure to the campaigns that have already been carried out in the country.

“The particle would cost R$30 a kilo,” she said.