Control of Spodoptera frugiperda by baculovirus receives approval from researchers

Already considered by producers as one of the most difficult pests to control in cotton, Spodoptera frugiperda, known as the fall armyworm, found a strong opponent that prevents its advance on crops, baculoviruses, as claimed by six researchers, four of whom are linked to public universities and renowned agribusiness foundations.

The group of experts conducted a series of advanced studies on a new baculovirus-based bioinsecticide.

Researchers Geraldo Papa (Unesp-SP), Lucia Vivan (MT Foundation), Germison Tomquelski (Chapadão Foundation-MS) and Marco Tamai (State University of Bahia) participated in the trials, in addition to specialists Janayne Resende and Marcelo Lima, both from AgBiTech, which is currently the world's largest producer of baculovirus. Present in Brazil for three years, the company has invested in the development of biological pest management products for agriculture.

The evaluation performed by the researchers found that controlling Spodoptera frugiperda by using baculovirus significantly reduces the caterpillar’s population in cotton. For them, the action of baculovirus-based bioinsecticides improves the protection of the plant and enhances the effect of chemical insecticides.

Marcelo Lima (Research & Development Manager at AgBiTech) pointed out that the series of studies carried out with the support of researchers focused on the biological insecticide, Cartugen, recently launched in Brazil. During the 2018-19 harvest, the research group found the effectiveness of this bioinsecticide in 34 commercial cotton areas in Bahia, Mato Grosso, Mato Grosso do Sul and Goiás, Lima stated.

Revenue increase

As the researchers attested to AgBiTech, applying Cartugen on cotton effectively protects the reproductive structures of the plant in the first and second phases. They also concluded that compared to the standard management techniques used by producers based only on chemical insecticides, the company's bioinsecticide achieved an average gain of 13.3 reproductive structures per cultivated linear meter. (See figures 1 and 2)

Figure 1. Percentage of retention of reproductive structures in the first and second cotton fruiting positions - Management with application of Baculovirus compared to the management by producers with only chemical insecticides. Source: AgBiTech (Data from Bahia audited by SGS do Brasil).

Figure 2. Average increase in the number of cotton reproductive structures per linear meter of plots with Baculovirus application compared to plots without Baculovirus insertion = producer management. Source: AgBiTech (data audited by SGS do Brasil).

Adriano Vilas Boas (General Director of AgBiTech for Latin America) explained that baculoviruses currently make up the largest group of viruses with a predatory effect on insects known to agro-science. According to Boas, these products carry a protein matrix with an alkaline pH, which, when ingested by caterpillars, releases viral particles directly into their intestines. “This causes infections in caterpillars,” Boas said, adding that due to these characteristics, baculoviruses are recognized by the International Committee for Action on Insecticide Resistance (IRAC) to be part of the group of 31 technologies with new modes of action.

Also, according to data provided by the researchers to the company, in addition to the agronomic benefits delivered by Cartugen to cotton crops, attention was drawn to the representative economic gain obtained in the 34 areas analyzed. During the tests, AgBiTech revealed there were increased revenues of between US$175 per hectare, discounting the additional investment of $21 per hectare.

Caterpillar attacks 

In crops targeted by AgBiTech’s study, Lima noted that the researchers observed that attacks by Spodotera frugiperda occurred mainly from the middle part of the cotton plant to the pointer. According to their analysis, the most critical phase of the pest's action was between the formation of flower buds and the appearance of the first bolls, with a significant reduction in fiber production.

“We note that this problem is present in both first and second generation transgenic plants, as their reproductive structures contain less of the Bacillus thuringiensis toxin. These areas are preferred by caterpillars to feed on,” concluded Lima. (See figure 3). Figure 3. Results of experiments demonstrating the strong feeding preference of Spodoptera frugiperda for the reproductive structures of cotton. Source: AgBiTech.

The original Portuguese version of this piece is from GRUPO CULTIVAR.