Rice bug pheromone application method is patented

The method is based on substances produced by the insects themselves, which are used to communicate between them, semiochemicals, eliminating the use of chemical pesticides.

The patent entitled "Compositions and methods for attracting and exterminating bedbugs of the genus Tibraca" (PI 0604617-7) is authored by researchers Miguel Borges, Maria Carolina Blassioli Moraes, Raul Alberto Laumann, from Embrapa Genetic Resources and Biotechnology (DF) and José Alexandre Freitas Barrigossi, from Embrapa Arroz e Feijão, (GO). This is the result of work lasting more than 15 years and which now depends on a partnership with a private company for its large-scale production and commercialization.

The technology is based on the use of pheromones to monitor and control stink bugs in Brazilian crops. It is a safe method, with great potential for use in integrated pest management (IPM) programs because it can significantly reduce and even eliminate the use of chemical pesticides on crops. In addition to being ineffective in controlling bedbugs, these pesticides cause resistance in insects, are harmful to those who apply them, eliminate beneficial insects such as bees and, in the case of irrigated rice, can contaminate water in rivers and springs.

The source for semiochemical technology is nature itself. Scientists have observed that insects use chemical substances to "warn" other insects about demarcating territory, feeding, risk of predators, reproduction, etc. When this communication occurs within the same species, the chemical compound is called a pheromone. It's like human language, only with chemicals instead of words.

Armed with this knowledge, the team led by researcher Miguel Borges began extracting pheromones in the laboratory and then placing them in traps to be distributed across crops. "In the case of bedbugs, we work mainly with the sexual pheromones produced by males", says the scientist.

After identification, the natural pheromone produced by the insect is synthesized in the laboratory and formulated into releasers that mimic the process that occurs in nature. They are then placed in traps in the field to capture and monitor the females.

Pheromone traps are distributed in crops with the aim of deceiving insects. Upon identifying the scent of the males, the females are attracted and captured in the trap. The ultimate aim is to monitor and control stink bug populations and, consequently, reduce damage to crops.

Insect causes up to 80% of losses

The stalk bug is one of the most important rice pests in Brazil. The insect sucks the sap in the culms (stems) of rice plants, reducing grain production and causing production losses of up to 80%. It occurs in most rice-producing regions in Brazil and is harmful to both cereal cultivation systems: irrigated (lowlands) and rainfed (highlands).

This is the second patent received by Embrapa related to semiochemical technologies for insect control. The first, in 2013, was aimed at the soybean bug complex and its success aroused the interest of a private company, which, based on a technical cooperation agreement signed with Embrapa, is developing and producing traps on a large scale. They will soon be on the market and available to soybean producers. "Now, we hope to repeat the same success with the stem bug. To this end, we are looking for partners to test the technology on a large scale", announces Borges.

Small-scale tests have already been carried out successfully at the Federal University of Rio Grande do Sul (UFRGS [www.ufrgs.br]) by researchers Josué Santana and Eduardo Hickel from the Agricultural Research and Rural Extension Company of Santa Catarina (Epagri-SC [http://www.epagri.sc.gov.br/]). "The results were good, but we cannot publicize them yet because they will be the subject of a scientific article, which is already in the final stages of preparation", comments the researcher.

The demand for a solution for the stink bug came from rice producers in the states of Goiás, Tocantins and Rio Grande do Sul, following requests made to researchers José Alexandre Barrigossi, from Embrapa Arroz e Feijão, and José Martins , from Embrapa Clima Temperado (RS).

According to Borges, the participation of Barrigossi, who is one of the inventors of the technology, was decisive for the studies, as he provided the Embrapa Genetic Resources and Biotechnology team with stalk bugs so that they could study their behavior, carry out tests on laboratory and field tests.

for partnerships

Companies interested in licensing this technology can contact the Technology Transfer team at Embrapa Genetic Resources and Biotechnology by email: cenargen.sipt@embrapa.br

Photo: Adilson Werneck