DEMOGRAPHIC AND PHYLOGENETIC EVOLUTION OF SITOPHILUS ZEAMAIS SUBSERVIENT TO MILLET IN SENEGAL (WEST AFRICA)

Food security remains a major challenge in Senegal. The millet that occupies the most important place in cereal production can play a fundamental role in taking up this challenge. But it is strongly ravaged by a beetle of the Curculionidae, Sitophilus Zeamais, in 4 agroecological zones (AEZ) where it is substantially exploited. The solution required to eliminate this pest is the use of pesticides, despite the horrible consequences that accompany it. It is possible to find healthy solutions. This article aims to identify the type of selection (positive or negative) that specifies each population and the degree of kinship of their individuals. The importance of detecting the demographic signal of AEZ populations is to be able to identify agroecological zones that are likely to favor survival or extinction of the insect. Positive selection militates more in favor of the adaptation of individuals than negative selection. Thus, insects of S. Zeamais subservient to millet were sampled in each AEZ. The exploitation of Cyt.B gene sequences led to the conclusion that the NBA population has undergone a positive selection, while the BMC population was negatively selected. SBA and SOHC populations have not been selected. Thus, the agroecological zone of the NBA is likely to favor the survival of the insect whereas the AEZ of the BMC is likely to favor a bottleneck. Phylogenetic trees have highlighted a close relationship of individuals in each AEZ.