Up and down from North to South: Latitudinal Distribution of Flea Beetle Genera in Continental Africa (Coleoptera, Chrysomelidae, Galerucinae, Alticini)

SIMPLE SUMMARY: Biodiversity is not evenly distributed on Earth. For phytophagous insects, we could expect increasing taxonomic richness from temperate to tropical latitudes, where plant diversity is high. In this paper, we explored the variation in the number of genera in one of the most widespread groups of phytophagous insects, flea beetles, from north to south on the African continent. We found that the number of genera depends on the number of vegetation types, the kind of vegetation, and some specific bioclimatic variables, leading to an up-and-down trend in taxonomic richness from north to south. ABSTRACT: The distribution of global biodiversity can be investigated based on comprehensive datasets and many methods to process them. The taxonomic diversity of phytophagous insects is typically linked to plant diversity, which increases from temperate to tropical latitudes. In this paper, we explored the latitudinal distribution of the flea beetle genera (Coleoptera, Chrysomelidae, Galerucinae, Alticini) on the African continent. We divided the area into latitudinal belts and looked for possible correlations with the number and types of vegetational divisions, the area of each belt, and the bioclimatic variables. The number of flea beetle genera is related to the number and types of vegetation divisions rather than the area of each belt. Some bioclimatic variables are highly related to the number of genera, which is higher within those belts where climate factors limit the oscillation of temperature over the year and favor high precipitations, especially in the warmest months. These biotic and abiotic factors lead to a two-peak trend in the taxonomic richness of flea beetle genera from north to south. Genera endemic to restricted areas are linked to the presence of high mountain systems and increase the taxonomic richness of the belt they belong to.