A new humicolous Parhydraena d'Orchymont, 1937 from South Africa (Coleoptera, Hydraenidae)

Parhydraena d'Orchymont, 1937 currently includes 19 species, 17 of which are endemic to South Africa (Perkins 2009; Bilton 2014). Most species of the genus are fully aquatic, but a few, together with members of other genera of Parhydraenini, occupy moist habitats rich in organic debris (Perkins 2009). These so-called humicolous habitats (Perkins Balfour-Browne 1994) occur both beside water and elsewhere, and have been colonised a number of times by primarily aquatic hydraenid lineages, particularly in Africa and Australasia (e.g. Perkins Balfour-Browne 1994; Perkins 2004a, 2004b; Perkins 2009; Hernando Ribera 2017). Within Parhydraena the toro group (sensu Perkins 2009) comprises four (sub)humicolous species which share a broad habitus, a marked constriction between the pronotum and elytral shoulders, and short legs and maxillary palpi. Whilst phylogenetic relationships within Parhydraena remain unclear in the absence of molecular data, the toro group as currently defined may not be monophyletic, given the differences in aedeagal anatomy observed amongst its members (see Perkins 2009). The most morphologically divergent species described to date is P. toro Perkins, 2009, whose simplified aedeagal anatomy differs considerably from all other known members of the genus. P. toro appears to be narrowly endemic to the inselberg of Table Mountain and surroundings, occurring in damp litter in Afromontane forests and beside seepages and streams (Perkins 2009; DTB pers. obs.). Here I describe a new species from a cool, high-altitude gully in the western end of Hex River Mountains, which closely resembles P. toro in external and aedeagal morphology and shares its humicolous microhabitat.

Two new terrestrial species of <i>Hydraena</i> Kugelann from the island of Bioko, Gulf of Guinea (Coleoptera: Hydraenidae)

The knowledge of the Hydraenidae of sub-Saharan Africa, and in particular of the genus Hydraena Kugelann, 1794, is most incomplete. As an example, in southern Africa only three species were described before the revision of Perkins (2014), which raised the number to 31. Only 15 species are currently known from Central Africa, between the Sahel and South Africa, all belonging to subgenus Hydraenopsis Janssens, 1972 (Trizzino et al. 2013), but many more remain to be described and discovered. The islands of the Gulf of Guinea are no exception to this lack of knowledge (Jones 1994), and only one species of the family was previously known, H. (Hydraenopsis) pagaluensis Hernando & Ribera, 2001 from Annobón (Hernando & Ribera 2001; Trizzino et al. 2013). In this paper we describe the first known species of Hydraenidae from Bioko, the largest and closest to the continent of these islands. The species were collected by our friend and colleague Vasily Grebennikov during a survey of the forest litter fauna of Annobón and Bioko. Despite considerable efforts no Hydraenidae were found in Annobón, and only these two species, in a single locality, in Bioko.