The 2026/27 corn season finds an encouraging signal in the behavior of one of the main threats that affected the crop in recent campaigns. The 51st report of the National Monitoring Network of Dalbulus maidis recorded a further decline of the corn leafhopper during the second half of September, with a marked reduction in abundance levels and an increase in localities where the insect was not detected at all.
The scenario is favorable for corn development in the country’s main productive regions. However, the Network warns that the current lower presence of the pest should not lead to a reduction in controls, especially as sowing advances and the first fields emerge.
While the Litoral, North-Central, and South-Central regions show records practically similar to those of the same period in 2025, the endemic regions —NOA and NEA— maintain levels slightly higher than last year.
The central recommendation is to maintain active and systematic monitoring, with special attention to two points: the management of volunteer or “guacho” corn plants and the monitoring of the leafhopper in early corn fields from crop emergence.
NOA and NEA: the pest also retreats, though with higher records than in 2025
In the NOA, the decline was significant. 24% of the monitored localities recorded no captures, while the lowest abundance level —between 1 and 4 adults per trap— accounted for 42% of the records.
Only Huasa Pampa, in Tucumán, fell into the highest abundance category, with more than 100 adults per trap.
The regional average dropped 54% in just one fortnight, falling from 18.15 to 8.34 adults per trap. Even so, the figure remains slightly above the level observed a year earlier, when 4.74 adults per trap were recorded.
In the NEA, the trend was similar. 58% of localities recorded no presence of Dalbulus maidis, while another 21% fell into the lowest abundance category. The highest concentration corresponded to Comandante Fontana, in Formosa.
The regional average was 6.85 adults per trap, compared with 4.40 recorded in the same period of 2025. In this region, 29% of the traps were also installed on early corn fields.
In the center and the Litoral, records are minimal
The situation is even more favorable in the regions where the leafhopper has historically shown lower presence.
In the Litoral, 85% of the monitored localities recorded no captures of Dalbulus maidis, while the remaining 15% fell into the lowest abundance category.
The average was just 0.36 leafhoppers per trap, a very low level and close to that recorded in the same period last year, when it was 0.14. In this region, 67% of the traps were also installed in corn fields.
The North-Central region also showed improvement in the indicators. Localities with no captures rose from 61% to 75%, while another 21% presented between 1 and 4 adults per trap. The remaining 4% did not exceed 20 adults.
The regional average was just 0.6 adults per trap, practically in line with the 0.41 recorded a year earlier. 28% of the traps were placed in fields with corn.
In the South-Central region, the picture was even more decisive: 98% of the traps recorded no detections of the pest. The average was just 0.02 leafhoppers per trap, exactly the same value as during the second half of September 2025.
Good scenario, but without letting the guard down
The widespread retreat of Dalbulus maidis creates a favorable scenario for corn and represents an important difference from the pressure the pest exerted in previous campaigns. However, the situation can change as the agricultural cycle advances.
For this reason, the National Monitoring Network stresses the importance of not interrupting surveillance. One of the main focuses is on volunteer corn plants, since their persistence can generate the so-called “green bridge,” allowing the leafhopper and associated pathogens to survive from one campaign to the next.
The second key aspect is the monitoring of early corn fields from emergence. Detecting the presence of the vector early allows management decisions to be taken with greater anticipation and, eventually, reduces the impact of the diseases transmitted by the pest.
The National Monitoring Network of Dalbulus maidis has been operating since 2024 and brings together Maizar, AAPPCE, Aapresid, CREA, INTA, and the EEAOC, with the aim of tracking the population dynamics of the insect in the different corn-growing regions and providing information for productive decision-making.