Annual and geographical variations in the specific composition of jassids and their damage on cotton in Ivory Coast

Abstract The aim of this study was to highlight the diversity of jassid species and their impact on cotton growing in Ivory Coast. The collections carried out in 2021 identified three species. Jacobiasca lybica (Bergevin & Zanon, 1922) is the most abundant, with proportions ranging from 73.3–93.3% depending on the site. The other two species are Empoasca papayae (Oman, 1937) (8.3%) and Empoasca facialis (Jacobi, 1912) (5%). In 2022, collections revealed the invasion of a new species, Amrasca biguttula (Shiraki, 1913), which became dominant with proportions of 90 to 100% depending on the site. Two other species, J. lybica (2.7%) and E. facialis (1.3%), cohabit with A. biguttula. Thus, while the damage noted in 2021 was attributable to J. lybica, that observed in 2022 is essentially due to A. biguttula, with incidences exceeding the economic impact threshold. The North-East of the cotton basin was the area most affected by attacks by these two species. The results of the study reveal significant changes in jassid species composition and climatic conditions in the cotton-growing areas of Ivory Coast, from one year to the next. This situation also explains the variations in damage levels.