Thyrinteina arnobia causes damage in Brazilian state

After having billions of losses with Helicoverpa armigera, the Northeastern Brazilian state of Bahia faces the threat of the Thyrinteina arnobia, which has attacked coffee, cocoa and even eucalyptus. The State Department of Agriculture started this month a phytosanitary program of biological control in the south of the state.

"The fist occurrence that raised a work was in the deep south because of eucalyptus. We need to control not only in large estates, but also in small farms,” affirmed agronomist Suely Xavier from the Bahia Agency of Agricultural Protection, a municipality of the Department.

"The caterpillars are among the main plagues that reach eucalyptus. There are 110 native species in Brazil. Population peaks are generally associated with events that trigger some type of environmental unbalance. This plague is an issue of national interest, from companies to the state, due to the economic importance for the region and also because of its share on Bahia's exports,” explains the agency's director, Oziel Oliveira.

At least 10 million wasps, natural predators of the Thyrinteina arnobia, were released in the region. “The program aims to establish a preventative control method, so what happened with Helicoverpa armigera in the western part of the state will not happen here,” explains the superintendent of Farm Business Policies at the Department, Guilherme Bomfim.

The plague control of caterpillars on planting of eucalyptus is being done with a biological insecticide based on Bacillus thuringiensis. The product is specific for caterpillars and does not pose risks to human and animal health. The mechanism of action of Bacillus thuringiensis happens through the release of toxins in the digestive system of caterpillars and it is harmless to all other organisms, including birds that feed on dead caterpillars and insects like bees.

The plant protection director, Armando Sá, explains that the infestation happened due to droughts in the Northeast of Brazil: “Already in 2014, we've had a survey in the areas of the extreme south and we have identified that had a caterpillar. This year, because of the climate, that have less rains, this plague came in a higher volume. So this was a necessary program”.

Sá tells that the properties of the region cannot be applied to agrochemicals because it has a “seal of international quality”. “Because of the international certification, they just use the biological product. These monitored properties are certified. Then, we cannot use the chemical product,” concludes.