Four new species of the diving beetle genus Laccophilus Leach, 1815 from Madagascar (Coleoptera, Dytiscidae, Laccophilini)

Abstract

Four new Laccophilus species are described from Madagascar, three belonging to the L. alluaudi-group (Laccophilus leguyaderi sp. nov., endemic of the Andringitra massif, L. bergsteni sp. nov., endemic of central highland mountains, and L. makay sp. nov., endemic of the Makay massif) and one belonging to the L. laeticulus group (L. rakouthae sp. nov., endemic of the Ankaratra massif). Habitus in dorsal and ventral views and male genitalia are illustrated for the new species (and for comparison, L. alluaudi and L. transversovittatus); furthermore, their habitat preferences and geographical distributions are described and illustrated. An identification key for all species of the L. alluaudi group is provided. The discussion is focused on the interest of the newly described taxa in the context of species radiations in Madagascar.

Diversification in the Comoros: Review of the Laccophilus alluaudi Species Group with the Description of Four New Species (Coleoptera: Dytiscidae)

“…This contrasts with the broader patterns found for the Comoros, with very few cases of intra-archipelago cladogenetic events among, for instance, reptiles [8] or birds [13]. The Laccophilus alluaudi group has its largest diversity on the island of Madagascar [32], where currently eight species are described but several additional species are known (Bergsten unpublished). Since the species group is not known from the African mainland [31], it is almost certain the Comoros were colonized from Madagascar.…”

“…Here we show that, for one lineage of aquatic insects that has diversified in Madagascar and colonized the Comoros with a single known species [31,32], it actually constitutes a flock of island-endemic species in the Comoros.…”

“…Six species were recognized, five in Madagascar and one in the Comoros. Recently, Manuel and Ramahandrison added three more species to the group [32], and several additional species, all from Madagascar, are known but have yet to be described (Bergsten unpublished). It has become clear that the lineage is one of just a handful of larger (>10 spp.)…”

“…It has become clear that the lineage is one of just a handful of larger (>10 spp.) in situ diversifications of diving beetles in Madagascar [32,33]. One species from the Comoros, L. tigrinus, was described by Guignot [34], and this is the only non-Madagascar species of the group.…”

The aquatic Adephaga of the Makay, central-western Madagascar, with description of two new diving beetle species (Coleoptera, Gyrinidae, Haliplidae, Noteridae, Dytiscidae)

“…Additional species recently described from the Makay include an Apocynaceae plant (Allorge et al 2015), a flea species living on bat (Laudisoit et al 2012), a fly (Feijen et al 2021), two millipedes (Wesener 2020) and an ant (Csösz et al 2021). To our knowledge, there are no published data concerning either Coleoptera or aquatic insects of the Makay apart from the recent description of the endemic diving beetle Laccophilus makay Manuel & Ramahandrison, 2020. Currently four families and 231 species of aquatic Adephaga (predaceous water beetles) are recorded from Madagascar. The Dytiscidae (in Malagasy, "tsikovoka") comprise 182 species of which 72% are endemic to Madagascar (however 78% are endemic to the Malagasy region, including Madagascar and the archipelagos of Comoros, Mascarenes, and Seychelles) (Bergsten et al, in press).…”