Extinct before discovered? Epactoides giganteus sp. nov. (Coleoptera, Scarabaeidae, Scarabaeinae), the first native dung beetle to Réunion island

We describe a new species of dung beetle, Epactoides giganteussp. nov., from a single female specimen allegedly collected in the 19th century on Réunion island and recently found at the Muséum national d’Histoire naturelle, Paris. This species differs from other species of Epactoides by larger size and a set of other distinctive morphological characters. Epactoides giganteussp. nov. is the first native dung beetle (Scarabaeinae) of Réunion, and its discovery expands the known area of distribution of the genus Epactoides, which was hitherto believed to be endemic to Madagascar. Like other taxa from Madagascar and peripheral islands (e.g., Comoro, Seychelles, Mascarenes), E. giganteussp. nov. may have reached Réunion by over-water dispersal. Given the rapid loss of biodiversity on Réunion island and the fact that no additional specimens were re-collected over the last two centuries, it is very likely that E. giganteussp. nov. has gone extinct. However, we have unconfirmed evidence that the holotype of E. giganteussp. nov. might be a mislabeled specimen from Madagascar, which would refute the presence of native dung beetles on Réunion. We discuss both hypotheses about the specimen origin and assess the systematic position of E. giganteussp. nov. by examining most of the described species of Madagascan Epactoides. Additionally, we provide a brief overview of the dung beetle fauna of Mascarene Archipelago.

New Mixaderus species from the Mascarene Islands (Coleoptera: Aderidae)

Following a previous revision of species of the genus Mixaderus Collado & Alonso-Zarazaga, 1996 (Coleoptera: Aderidae) from Madagascar and the Mascarene islands, I describe here six new species from the same genus from La Réunion and Mauritius: Mixaderus reunionensis n. sp.; Mixaderus chassaini n. sp.; Mixaderus lemagneni n. sp.; Mixaderus tamisieri n. sp.; Mixaderus voisini n. sp.; Mixaderus mauritiensis n. sp. I also provide an updated key to the Mixaderus species from the Mascarene archipelago.

Echiniscidae in the Mascarenes: the wonders of Mauritius

Many regions of the world remain unexplored in terms of the tardigrade diversity, and the islands of the Indian Ocean are no exception. In this work, we report four species of the family Echiniscidae representing three genera from Mauritius, the second largest island in the Mascarene Archipelago. Two species belong in the genus Echiniscus: Echiniscus perarmatus Murray, 1907, a pantropical species, and one new species: Echiniscus insularissp. nov., one of the smallest members of the spinulosus group and the entire genus, being particularly interesting due to the presence of males and supernumerary teeth-like spicules along the margins of the dorsal plates. The new species most closely resembles Echiniscus tropicalis Binda & Pilato, 1995, for which we present extensive multipopulation data and greatly extend its distribution eastwards towards islands of Southeast Asia. Pseudechiniscus (Meridioniscus) mascarenensissp. nov. is a typical member of the subgenus with elongated (dactyloid) cephalic papillae and the pseudosegmental plate IV’ with reduced posterior projections in males. Finally, a Bryodelphax specimen is also recorded. The assemblage of both presumably endemic and widely distributed tardigrade species in Mauritius fits the recent emerging biogeographic patterns for this group of micrometazoans.

Taxonomic revision of Jumellea (Orchidaceae, Angraecinae) in the Mascarenes

We present a taxonomic revision of the genus Jumellea (Angraecinae; Orchidaceae) in the Mascarenes based on morphological study and field observations. We examined 328 specimens mostly from the MAU, P and REU, and recognise nine species. We provide a key, morphological descriptions, distributions, habitats, phenologies and conservation assessments following the Red List categories and criteria (IUCN). All nine species are present on Réunion with two being endemic there, and five have been confirmed on Mauritius, none of them endemic. The single species recorded for Rodrigues is also the only one found on all three islands of the Mascarenes and Madagascar. Five species are endemic to the Mascarene Archipelago, whereas the other four also occur in Madagascar. All nine species qualify as threatened with extinction on at least one of the islands of the Mascarenes. Two species are probably extinct on one island, and only two species on Réunion are not threatened.

A new species of Nephus (Nephus) (Coleoptera, Coccinellidae) described from Reunion Island

We report here a new species belonging to Nephus (Nephus) Mulsant. Nephus (Nephus) apoloniasp. nov. was collected in the Reunion Island (Mascarene Archipelago, Indian Ocean). We describe this new species and redescribe and illustrate three other Nephus species already known from Reunion: Nephus (Nephus) oblongosignatus Mulsant, 1850, Nephus (Geminosipho) reunioni (Fürsch, 1974) and Nephus (Nephus) voeltzkowi Weise, 1910. Furthermore, we present a phylogenetic tree for these four species and calculate the genetic distances between them, using high-throughput DNA sequencing of the mitochondrial genome. The similar external morphology of N. apoloniasp. nov. and N. voeltzkowi very probably explains why individuals from the first species have been mistakenly identified as the latter and were not recognized as different until now. Other than external and genitalia traits, the present study provides molecular evidence confirming these are indeed two different species.

Mascarapion, a new genus of the Apioninae (Coleoptera, Curculionoidea) from the Mascarene Islands

A new genus, Mascarapion, is erected, endemic to the Mascarene Archipelago. Three species are included as new combinations: M. mauritii (Beguin-Billecocq, 1905), M. roudieri (Richard, 1957) and M. richardi (Alonso-Zarazaga, 1983). Mascarapion richardi is given a new status of distinct species, its morphological differences from M. roudieri are described. The problematic placement of the new genus in existing apionine tribes is discussed.

Disentangling the diversity and taxonomy of Hymenophyllaceae (Hymenophyllales, Polypodiidae) in the Mascarene archipelago, with ecological implications

We here explore the diversity and ecology, and update the taxonomy of the fern family Hymenophyllaceae, which forms one of the most diverse and emblematic fern assemblages in rainforests of the Mascarene archipelago in western Indian Ocean. Since 1999, we extracted data from floras, literature, and field investigations conducted, and from an exhaustive examination of the collections at P, REU, and MAU. Our checklist recognizes 26 taxa involving 23 species, 2 local varieties and 1 new forma. We reconsider area of distribution in Mascarene Hymenophyllaceae and at least 3 species appear to be restricted to the archipelago. We discuss the updated taxonomy and discrimination of each taxon (including a new nomenclatural proposition for Hymenophyllum tenellum here renamed as H. fumarioides) and provide a dichotomous key. We present and discuss the ecology and elevational distribution of each species, in addition to the local endemicity. Finally, we emphasize the importance of threatened lowland rainforests and of wet ravines in semi-dry forests, which host a high level of diversity in the context of local conservation of habitats.