Distribution patterns and habitat preference for the genera-group Blepharida s.l. in Sub-Saharan Africa (Coleoptera: Chrysomelidae: Galerucinae: Alticini)

This study analyzes the distributions in Sub-Saharan Africa of the endemic and sub-endemic flea beetle genera, Calotheca Heyden and Blepharidina Bechyné, this latter subdivided in the two subgenera, Blepharidina s.str. and Afroblepharida Biondi & D'Alessandro. To compare and correlate their pattern of geographic range and the current distribution of the terrestrial ecosystems occurring in the Afrotropical Region, 588 presence records were considered, 61 for Afroblepharida, 93 for Blepharidina and 434 for Calotheca. Afroblepharida, mainly occurring in the region of Africa between the 20th parallel N and the equator, has a clear preference (62%) for desert and semi-desert habitats, while Calotheca, widespread in the southern Africa, mainly in the eastern belt between the 20° and 40° meridian at E of Greenwich, Arabian Peninsula and Israel, results comparatively more mesophilous, preferring savannas (54%), and forests (37%). Finally, Blepharidina, mainly occurring in the region between the equator and the Tropic of Cancer, takes an intermediate position between Afroblepharida and Calotheca, with preference for savannah (47%), forest (32%), and semi-desertic (21%) habitat. Presence records were also used to build Ensemble models for current and past climatic conditions (Last Glacial Maximum and Mid-Holocene). The results, also in this case, show a clear separation between Afroblepharida and Blepharidina in central African's predicted suitable areas, as well as for Calotheca, which is predicted to occur especially in southern Africa. Post-modeling analyses on predicted suitable areas reinforced the patterns of habitat preference observed through occurrence localities and showed that the two genera once shared a large area, mainly composed by savannas, which progressively shrunk and changed to more desertic conditions.