Locusts attacking Brazil are different from those in Argentina

By Leonardo Gottems, Reporter for AgroPages

After attacking crops in Argentina and Paraguay, clouds of locusts have arrived in southern Brazil over the past two months. However, local authorities point out that the insects identified in the country's southernmost state, Rio Grande do Sul, are not the same species as those in Argentina.

According to Ricardo Felicetti (Agronomist and Head of the Plant Health Defense Division), individuals were collected in the northwest region of Rio Grande do Sul to identify the species of locusts occurring in the region, to determine their location, incidence and intensity of defoliation of crops and forest areas.

“Two species of locusts belonging to the Romaleidae Family, Zoniopoda iheringi and Chromacris speciosa, have been identified by specialists. These are not migratory locusts from the Acrididae Family, which worried the Phytosanitary Emergency Ordinance due to the risks posed by their entry into Argentina in May,” Felicetti said.

A total of 4,740.5 hectares (ha) were inspected, of which about 58.26% (2,762 ha) are native forest areas. Another 41.74%, the equivalent of 1,978.5 ha, are agricultural areas with soybean, corn and winter crop cultivation.

In total, 1,511 hectares have locusts present. In the agricultural area, an average incidence of 58.26% and an average defoliation intensity of 0.35% were observed. Considering the total area surveyed, the average incidence is 55% and the defoliation intensity is 0.34%.

According to the inspections, damage to agricultural crops has been minor so far, and in areas with greater focus, a defoliation rate of about 10% was observed in agricultural crops, especially in areas bordering native forests, with a density of infestation of about 5 individuals/m². Inside the crop area, the defoliation observed was less than 5%, with less than 0.5 individuals/m².

In native forests, a major infestation of locusts was observed, mainly specimens of Timbó (Ateleia glazioveana), with a defoliation rate of up to 100% of leaves and grouping of tens to hundreds of individuals per tree. A defoliation rate of around 5% was observed in non-commercial citrus orchards located in areas close to native forests.

An emergency plan has already been drafted if case of the need for intervention against the insects.