New caterpillar resistant to biotechnology invades another Brazilian region

The caterpillar Rachiplusia nu, until now absent in Brazil, has invaded yet another agricultural region of the country, the West of Bahia, proving that it resists varieties with biotechnologies.

The revelation was made exclusively to AgroPages by agronomist Luis Kasuya, a researcher at Kasuya Agricultural Intelligence.

″It did not take proportion in the harvest, but we have already started to warn about possible advances of the plague. The producer has to be attentive and monitor his soy crop with IPRO (Intacta, Bayer) or conventional methods,″ says Kasuya, who has more than 30 years of experience.

According to him, IPRO has a recommendation in the leaflet only for Chrysodeixis includens (false medicine).

According to the researcher and consultant, last year Kasuya Consultoria made a strategic application of insecticide in some plots, due to the presence of Rachiplusia nu, in an oilseed area in Bahia monitored by the company.

″Our idea is to put research first. If it is good for the producer, we will recommend it,″ he said.

″The caterpillar can bring a high rate of defoliation to the IPRO varieties, now adopted almost unanimously by soybean farmers in western Bahia. Rachiplusia nu tends to become a problem,″Kasuya said.

For the researcher, both for managing naked Rachiplusia and other caterpillars, ″like Spodoptera frugiperda″, the producer and his consultants must evaluate in advance which biotechnologies to adopt.

″This measure is very important. Let us emphasize, integrated pest monitoring, integrated pest management (IPM), is essential, indispensable these days.″

Last month, several consultancies operating on the agricultural frontier also reported records of the presence and pressure of Rachiplusia nu, mainly in crops in the Brazilian states of Goiás, Minas Gerais, São Paulo, Mato Grosso, and Paraná.

Kasuya emphasized that Rachiplusia nu may regain relevance in the list of potentially harmful pests to Brazilian soybeans.

″If it enters the crop in the vegetative phase, it will be easy to control, because the crop is exposed,″ he said.

However, he added, ″if it appears in the breeding season when the soybean ‘closed’, the pest will move in half and there will be a need to change the strategy, including the application technology.″

The consultant also clarified that as it is a caterpillar with defoliating action, it is essential to avoid foliar losses in the crop.

″More modern soybean varieties have a low leaf area index (LAI). In view of this, we recommend preserving the leaf area of the plants, as well as maintaining high photosynthetic rates and the thousand-grain mass (MMS). Such factors have a positive effect on crop productivity,″ Kasuya concluded.

Kasuya is among the renowned researchers who are currently evaluating the development of a solution by AgBiTech Brazil, based on baculovirus, specific for controlling the caterpillar Rachiplusia nu.

(Editing by Leonardo Gottems, reporter for AgroPages)