Cosmopolites sordidus G. as a dispersal agent of Fusarium oxysporum f. sp. cubense Tropical Race 4 (Foc TR4) in Cavendish banana crops (Musa AAA).

Cosmopolites sordidus Germar is the most limiting insect pest in the production of musaceous crops. The objective of this study was to analyze the relationship between the population density of C. sordidus and the incidence of Fusarium oxysporum f. sp. cubense Tropical Race 4 (Foc TR4) in Cavendish banana plantations with high, medium, and low disease incidence in La Guajira, Colombia. The farm's weekly phytosanitary records from 2022 to 2023 defined the incidence levels as follows: high (>80 foci), medium (>30-80 foci), and low (<30 foci). For each incidence level, we installed ten ramp-type traps baited with an aggregation pheromone (Cosmolure®), totaling 30 traps. The number of C. sordidus individuals, Foc TR4 incidence, and climatic variables (precipitation, relative humidity, and temperature) were recorded weekly over 49 weeks. C. sordidus were present throughout the entire evaluation period, with populations ranging from 1 to 20 individuals per trap per week. Weevil populations showed a strong positive correlation with relative humidity and temperature (p < 0.001), closely associated with the insect's life cycle. Granger causality tests (p < 0.001) demonstrated statistically in the field that increases in C. sordidus populations preceded the appearance of Foc TR4 foci by one to two months (F = 38.22, p < 0.001), explaining 87.1% of variability in disease incidence. These results provide statistical field-level evidence that C. sordidus acts as a dispersal agent of Foc TR4 and highlight the importance of including this insect in disease prevention and management strategies for musaceous crop production.