Flutuação populacional de Melanaphis spp. em ambiente de cerrado no ano de 2022

Abstract

The increasing economic importance of sorghum in Brazil, particularly in tropical regions such as the Cerrado, has highlighted the presence of pests, including the yellow sugarcane aphid (Melanaphis sorghi Theobald), which has become a significant challenge for agricultural production. The damage caused by this pest can compromise sorghum productivity, leading to yield losses of up to 100% in more susceptible varieties. The geographical expansion of this aphid may be associated with abiotic factors, such as temperature, which influences the rate of pest infestation in the environment. Given this context, this study aimed to evaluate the population fluctuation of winged Melanaphis spp. in the Cerrado, considering climatic factors such as temperature, precipitation, and relative humidity throughout 2022. The study was conducted at the Capim Branco Experimental Farm of the Federal University of Uberlândia (UFU), using yellow pan traps for weekly collection of winged individuals, along with meteorological data obtained from the National Institute of Meteorology (INMET). Specimens were identified based on morphological characteristics, and the collected data were subjected to Pearson correlation analysis to assess the influence of climatic variables on population density. A total of 319 Melanaphis spp. specimens were recorded, with population peaks occurring in May and August, coinciding with moderate temperatures ranging from 16°C to 24°C. A significant negative correlation was found between the population of winged Melanaphis spp. and minimum (r = -0.61; p < 0.001), average (r = -0.62; p < 0.001), and maximum temperatures (r = -0.54; p < 0.001), while no correlation was observed for precipitation (r = -0.03; p < 0.83) and relative humidity (r = -0.01; p < 0.90) with aphid population density. Furthermore, periods of higher population density coincided with the absence of rainfall and low humidity levels. It is concluded that moderate temperatures and dry conditions favor the population increase of Melanaphis spp. in the Cerrado, with May being the peak population month, characterized by a dry climate and mild temperatures in the Minas Gerais region.