Abstract:
In this article, it was a question of highlighting the models of demogenetic and phylogenetic
evolution of Sitophilus zeamais, the main pest of maize stocks in Africa, in 2 humid and arid
agroclimatic zones of West and Central Africa.
Methods: The insects were therefore collected from the same storage means, in four countries in
the humid agro-climatic zone and five in the arid agro-climatic zone.
Results: The mitochondrial DNA of these insects was extracted and the cytochrome b gene
sequenced. The exploitation of these sequences has shown a demographic expansion in arid
agro-climatic zones and a demographic stability in humid agro-climatic zones. The phylogenetic
trees did not clearly show a genetic structure of the insect according to the two agro-climatic
zones and a close phylogenetic relationship of the individuals of the two sets.
Conclusion: The demographic stability and the low genetic diversity of the population of the
humid agro-climatic zone can be the signal of a bottleneck or the pledge of a population on the
brink of extinction. While the population of the arid agro-climatic zone exhibiting a population
expansion and a high genetic diversity may exhibit a greater resilience.
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