Dytiscidae, Noteridae and Hydrophilidae of semi-arid rivers and reservoirs of Burkina Faso: species inventory, diversity and ecological notes – JBES

By: I. Kaboré

Key words: Aquatic beetles, Vegetation, Semi-arid, Burkina Faso, West Africa.

Abstract

Conservation of biodiversity is a major concern due to climate change and pressure from human activities. Knowledge of aquatic insects and their ecology particularly in West Africa is still scanty and fragmented. To fill this gap, we investigated the structure of aquatic beetle assemblages from 18 lentic and lotic water bodies (rivers and reservoirs) in Burkina Faso, and we explored their relationship with environmental variables. Following a multi-habitat sampling approach, all beetles were collected with a hand net, and identified using taxonomic manuals and keys. A total of 11 species of Noteridae in three genera, 27 species of Dytiscidae in 10 genera and 22 species of Hydrophilidae in nine genera were identified in this study. MINOLTA DIGITAL CAMERA Among these, 24 species are here reported for the first time from Burkina Faso. The species richness was high in the reservoirs with habitats dominated by “water lettuce” Pistia stratiotes (species diversity, sd=11.0±9.00 Shannon Wiener index, H=1.79±1.1) and “reed beds” (species diversity, sd=7.63±1.78; Shannon Wiener index, H=1.51±0.25) in comparison with rivers (sd=2.25±0.75; H=0.35±0.20). The results also showed that the species richness is significantly correlated with vegetation cover. Thus, emergend water plants were found to be the main factor influencing beetles species richness. The observed relationship between vegetation cover and beetle richness may provide significant insights that motivate future efforts in research as well as in habitat conservation measures in West Africa.