Climate puts pressure on caterpillars in Brazilian soybean crop 2023/2024

The high temperatures and significant humidity caused by the climatic phenomenon El Niño have created ideal conditions for developing major caterpillar pests affecting soybean crops, according to agronomist Carlos Melo, insecticides manager at UPL Brasil.

He stated that this threat, although already known, could be even more severe against Brazil's leading agricultural commodity, which is expected to exceed 162 million tons in the 2023/2024 harvest, according to the Brazilian National Supply Company (Conab).

One example he mentioned is the Spodoptera Frugiperda, popularly known as the fall armyworm, which can cause damage at all soybean growth stages.

″During the initial phase, this pest attacks the ‘collar’ region, cutting the plants close to the ground, resulting in death and compromising crop development. In some cases, it also feeds on flowers and pods, resulting in significant productivity losses," Melo said.

As for the Helicoverpa Armigera, he highlighted its ability to feed on the leaves and stems of host plants but showed a particular preference for reproductive structures, such as floral buds and pods.

"When feeding, they can cause deformities or rot in these parts, even causing them to fall off the plant," he affirmed.

"The result of this super-attack on plant structures, which could reach levels exceeding 30% across the soybean field in the case of high infestations, according to the Brazilian Agricultural Research Corporation (Embrapa), is a loss of productivity, leading to lower economic returns," the specialist warned.

He emphasized that the primary approach to combat caterpillars is Integrated Pest Management (IPM). The Food and Agriculture Organization of the United Nations (FAO) defined IPM as a pest management system that considers the environment and population dynamics of the species.

Its main tools included monitoring insect populations, biological control to promote natural enemies, and using chemical control only when necessary, i.e., when the infestation reached a harmful level for the crop.

As part of IPM actions, Melo highlighted Shenzi (Chlorantraniliprole), an insecticide that acts systemically to control caterpillars, quickly and effectively ceasing their feeding and mitigating the damage and its impact on productivity.

One of its modes of action is depleting the internal calcium stores in muscle cells, leading to a rapid cessation of feeding, generalized lethargy, muscle paralysis, developmental inhibition, and mortality within 1 to 72 hours (depending on the caterpillar's stage).

In addition to Helicoverpa armigera and Spodoptera frugiperda, UPL's solution is also registered for combating Anticarsia gemmatalis, Chrysodeixis includens, Crocidosema aporema, Elasmopalpus lignosellus, Hedylepta indicata, Heliothis virescens, Rachiplusia nu, and Spodoptera eridania in soybeans.

(Editing by Leonardo Gottems, reporter for AgroPages)