Three-year analysis of cotton boll weevil (anthonomus grandis Boheman) captures and their relationship with meteorological factors in an experimental field in the central Chaco region

Abstract

Cotton boll weevil, Anthonomus grandis B. (Coleoptera: Curculionidae) is the most damaging pest of the cotton crop in the Americas. This insect species causes high yield losses mainly due tothe feeding activity and oviposition damage occasioned by the adult insects in the reproductive structures of cotton plants. One of the Integrated Pest Management tactics currently applied to monitoring the population dynamics and control this pest species involves the use of pheromone traps. Previous studies have demonstrated that climatic variables of the growing area affect the boll weevil population dynamics. The aims of this study are to analyze the results ofmonitoring the cotton boll weevil traps located in the experimental field of the Estación Experimental Agropecuaria Saenz Peña (Chaco province, Argentina) during the last three years and evaluate the incidence of the main meteorological variables on the insect capture data obtained over time. Eighteen pheromone traps were installed in strategic points of the experimental field and weekly revised. In parallel, meteorological variables of the period August 2021 toSeptember 2024 were registered and analyzed. Our results evidenced that the boll weevil population dynamic appeared directly related to the temperature and relative humidity, in addition to the presence of cotton crop. In fact, during the last year analyzed we observed a decrease in the average monthly number of captures per trap, particularly in the month of May likely associated with the unstable prevailing climatic conditions with an unexpected drop in the temperature. The evaluation of the climate variables in conjunction with the monitoring of the boll weevil population dynamics allows improving the criterion to predict a high pest population growth in thecotton fields, and this information should be considered for programming the next cotton season.