Population parameters of two water scavenger beetles: Derallus angustus Sharp, 1882 and Enochrus vulgaris (Steinheil, 1869) (Coleoptera: Hydrophilidae) in permanent ponds: spatial distribution and microhabitat preference. Trop Zool. 2016;30(1):1-12. doi:10.4081/tz.2017.58