Climate-driven shifts in the spatial distribution of Bemisia tabaci (Gennadius, 1889) populations in the cotton-growing area of Côte d’Ivoire

A significant outbreak of Bemisia tabaci populations has been documented in the cotton-growing regions of Côte d'Ivoire over the past two decades. This study aimed to characterize the spatial variability in infestation levels in relation to temperature and rainfall, to inform revisions to phytosanitary management strategies for this pest. We conducted 15 systematic pest assessments between the 30th and 128th days after crop emergence to quantify infestation intensity. Climatic variables, including temperature and precipitation, were integrated to create geospatial maps that illustrate variations in infestation patterns across the cotton belt. Statistical analyses revealed highly significant differences in infestation levels among localities (χ² = 2209.90; df = 42; p < 0.001). The period from 2012 to 2017 showed markedly increased whitefly pressure, averaging 78.63 insects per 30 plants, compared to 65 insects per 30 plants during 2003 to 2008. The proliferation pattern and spatial distribution of B. tabaci were strongly influenced by climatic conditions, particularly precipitation and temperature. The northeastern cotton-producing zone, characterized by low annual rainfall (less than 1,200 mm) and elevated mean temperatures (26.8°C to 28°C), emerged as a high-suitability area for the expansion of B. tabaci populations. Given the ongoing climate change, marked by decreasing rainfall and rising temperatures, we anticipate an increased risk of B. tabaci population growth. These findings provide essential baseline information for optimizing integrated pest management strategies to control B. tabaci in Côte d’Ivoire's cotton production systems.