Sisal extract is tested as insecticide against Aedes aegypti

A study in Brazil authored by the Federal University of Paraíba in partnership with Embrapa resulted in a natural insecticide based on the extract of the leaves of sisal (Agave sisalana), which has shown to be effective against the larvae of Aedes aegypti, a mosquito that transmits diseases such as dengue, zika and chikungunya. The product attacks the guts of the larvae leading to death in less than 24 hours.

According to the vice-director of the Center of Biotechnology of the Federal University of Paraíba, Fabíola Nunes, coordinator of the research, the biological essays concluded that the death of the larvae through a dose of four millimeters of sisal for each 100 liters of water. “We have tested on larvae and obtained a promising result with 100% of mortality at the larval stage, which is the aquatic stage,” he said.

The sisal extract has several organic compounds with a highlight for saponins, which can cause toxicity, irritation and even death of ticks, caterpillars of some species and other insects. According to the researcher, the tests have shown that, if diluted on recommended proportions, the ingestion or contact with the extract with the skin does not cause any type of harm for animals such as mice and sheep. “At the early tests, we have verified that it is not toxic for laboratory animals. We need to do more tests to determine the toxicity for other animals,” he said.

The next steps will be to make studies to provide the product safely and with detailed instructions. “The research still needs to respond to some questions such as: for how long the product maintains the effect; what is the action mechanism; and which is the way to provide the product in the market,” affirmed Fabíola.

Effectiveness against caterpillars

The powder extract demonstrated effectiveness against caterpillars on cotton and soybeans as well as ticks on cattle. The initial research of the sisal extract with bioinsecticide proposal was developed in partnership with the Union of the Industry of Vegetable Fibers of the State of Bahia, the Department of Science, Technology and Innovation of Bahia and the Organization for Food and Agriculture of the United Nations (FAO).

Rich in sugar, nutrients and other components, the sisal has aroused interest of research for the obtainment of high added value substances as natural crop protection, sweeteners, nanocellulose and bacterial cellulose (a special type of cellulose with several applications of biomedical research, since the artificial skin for burns to the engineering of organs).