Larval morphology of the Madagascan endemic diving beetle genus Hovahydrus Biström, 1982 (Coleoptera: Dytiscidae) and phylogenetic comparison with other known Hyphydrini.

We describe for the first time the instar III larva of the diving beetle genus Hovahydrus Biström, 1982, based on H. praetextus (Guignot, 1951) and a new species yet to be described (identified here as Hovahydrus sp. near H. minutissimus (Régimbart, 1903)). We include detailed morphometric and chaetotaxic analyses of the cephalic capsule, head appendages, legs, last abdominal segment and urogomphi in order to discover useful characters for distinguishing Hovahydrus larvae from those of other known Hyphydrini (Coleoptera: Dytiscidae, Hydroporinae). A provisional parsimony analysis based on larval characteristics of 11 Hyphydrini species in eight genera was conducted using the program TNT. Larval morphology supports a close relationship between Hovahydrus, Hyphydrus Illiger, 1802, and the endemic South Africa genera Andex Sharp, 1882, Coelhydrus Sharp, 1882, Darwinhydrus Sharp, 1882 and Primospes Sharp, 1882.

Remaining forests on the Central Highlands of Madagascar-Endemic and endangered aquatic beetle fauna uncovered.

Madagascar is known for its high endemism and as many as 90% of this unique diversity are forest-dwellers. Unfortunately, the forest cover of Madagascar is decreasing at an alarming rate. This decrease can also affect aquatic insects, but our knowledge on aquatic insect diversity and distribution on Madagascar are limited. Although the eastern rainforests are considered the most diverse, the Central Highlands of Madagascar also harbors unique microendemic fauna but has been less studied. Here, we analyze the aquatic Adephaga beetle fauna of three remaining protected forests of the Central Highlands. Diversity, abundance, and uniqueness are compared between and within natural forests and surrounding grasslands. At least 15 undescribed species were found, highlighting the Central Highlands as an important area for endemism. The natural forests and the surrounding grasslands differed significantly in species assemblages. Interestingly, the three remaining forests differed in their assemblages with the geographically more distant Manjakatompo Ankaratra having the most unique fauna but also the highest altitude span. By contrast, the species composition was similar between the peripheral zones of each of the three remaining forests. The similarity of the fauna in the peripheral open habitats illustrates how some local forest endemics are replaced with widespread generalists in degraded habitats. Our study shows that the remaining forests of the Central Highlands of Madagascar are important refuges of unique fauna at high risk of extinction.

Dendrothripoides moundi (Thysanoptera, Thripidae), a new species from Madagascar.

The genus Dendrothripoides was originally described by Bagnall (1923) from India and is currently represented by five species (ThripsWiki 2020). Dendrothripoides innoxius (Karny) is widely distributed in the Oriental and Pacific regions; D. microchaetus Okajima is from the Philippines and Indonesian archipelago; D. nakaharai Reyes known only from the Philippines, D. poni Kudo from Thailand, and D. venustus Faure from Rhodesia [Zimbabwe] and South Africa (Faure 1941; Kudo 1977; Bournier 2000). Little is known about the biology of these species because collections often have samples with few specimens. D. innoxius is considered a minor pest on Ipomoea crops (Watson Mound 2020) but adults have been taken on the leaves of plants in numerous families (Asteraceae, Convolvulaceae, Dioscoreaceae, Musaceae, Poaceae). Dendrothripoides was classified within the Panchaetothripinae by Priesner (1957) for having a reticulate body surface. However, Ananthakrishnan (1963) indicated that the similarities are superficial, and that this genus should be classified in the Aptinothripina of the Thripinae because the pronotum lacks long setae. The genus is now not included in the Anaphothrips genus-group (Masumoto Okajima 2017), but the systematic position is unclear with a recent morphological phylogenetic analysis indicating a position near the Panchaetothripinae that may be due to superficial resemblance (Zhang et al. 2019).

Discovery of a specialist Copelatinae fauna on Madagascar: highly ephemeral tropical forest floor depressions as an overlooked habitat for diving beetles (Coleoptera, Dytiscidae).

Diving beetles are generally aquatic and live submerged in water during larval and adult stages. A few groups have colonised hygropetric habitats and fewer species still can possibly be referred to as terrestrial. Here we describe six new Copelatine species that were mainly found in dry shallow forest floor depressions in the eastern and northeastern lowland humid forests of Madagascar. Three new species are described in each of the two genera Copelatus and Madaglymbus: Copelatus amphibius sp. nov., Copelatus betampona sp. nov., Copelatus zanatanensis sp. nov., Madaglymbus kelimaso sp. nov., Madaglymbus menalamba sp. nov., and Madaglymbus semifactus sp. nov. Diagnosis, description, known distribution, ecology, and conservation notes are provided for each species. All species are illustrated with a dorsal habitus image, ventral and lateral views of the male penis, and parameres. Photographs of the unusual terrestrial habitats where the species were found are provided. Madaglymbus menalamba sp. nov. is also documented with macrophotos and videorecordings of the terrestrial locomotion and behaviour in the field. Although these species should not be classified as terrestrial, or even semi-terrestrial Dytiscidae, they seem to be specialists of very ephemeral aquatic habitats and stay put instead of disperse when the habitat dries up. It is hypothesised that this lifestyle and behaviour on Madagascar is restricted to the high-precipitation humid forest regions mainly in the east. It may also represent a transition step, or stepping-stone, towards becoming fully terrestrial, a step that the few known terrestrial Dytiscid taxa once passed through. It is very likely that this type of habitat is overlooked for aquatic beetles, not only in Madagascar, and the six species herein described may be just the "tip of the iceberg".

Taxonomic revision of the genus Copelatus of Madagascar (Coleoptera, Dytiscidae, Copelatinae): the non- erichsonii group species.

The genus Copelatus Erichson, 1832 (Coleoptera, Dytiscidae, Copelatinae) of Madagascar is revised in two parts. This review is restricted to the Copelatus species that have fewer than ten elytral + one submarginal stria, including all species except those of the erichsonii species group. Both morphological and molecular (mitochondrial COI) data are used in an integrative taxonomic approach. Thirteen species are recognised, of which five are described as new: Copelatus ankaratra sp. nov., Copelatus kely sp. nov., Copelatus pseudostriatus sp. nov., Copelatus safiotra sp. nov. and Copelatus vokoka sp. nov. Copelatus unguicularis Régimbart, 1903 and Copelatus apicalis Fairmaire, 1898 are both transferred to the genus Madaglymbus Shaverdo & Balke, 2008 (comb. nov.). Copelatus mimetesGuignot 1957 is a junior synonym of the widespread Afrotropical-Arabian Copelatus pulchellus (Klug, 1834) (syn. nov.). Copelatus marginipennis (Laporte, 1835) is reinstated (stat. nov.) as a valid species with Copelatus aldabricus Balfour-Browne, 1950 and Copelatus aldabricus var. simplex Guignot, 1952 as junior synonyms (syn. nov.). We designate lectotypes for Colymbetes marginipennis Laporte, 1835 and Copelatus obtusus Boheman, 1848. Copelatus peridinus Guignot, 1955 is recorded for Madagascar for the first time and Copelatus nodieri Régimbart, 1895 is rejected as a species present in Madagascar.

In or out-of-Madagascar?--Colonization patterns for large-bodied diving beetles (Coleoptera: Dytiscidae).

High species diversity and endemism within Madagascar is mainly the result of species radiations following colonization from nearby continents or islands. Most of the endemic taxa are thought to be descendants of a single or small number of colonizers that arrived from Africa sometime during the Cenozoic and gave rise to highly diverse groups. This pattern is largely based on vertebrates and a small number of invertebrate groups. Knowledge of the evolutionary history of aquatic beetles on Madagascar is lacking, even though this species-rich group is often a dominant part of invertebrate freshwater communities in both standing and running water. Here we focus on large bodied diving beetles of the tribes Hydaticini and Cybistrini. Our aims with this study were to answer the following questions 1) How many colonization events does the present Malagasy fauna originate from? 2) Did any colonization event lead to a species radiation? 3) Where did the colonizers come from--Africa or Asia--and has there been any out-of-Madagascar event? 4) When did these events occur and were they concentrated to any particular time interval? Our results suggest that neither in Hydaticini nor in Cybistrini was there a single case of two or more endemic species forming a monophyletic group. The biogeographical analysis indicated different colonization histories for the two tribes. Cybistrini required at least eight separate colonization events, including the non-endemic species, all comparatively recent except the only lotic (running water) living Cybister operosus with an inferred colonization at 29 Ma. In Hydaticini the Madagascan endemics were spread out across the tree, often occupying basal positions in different species groups. The biogeographical analyses therefore postulated the very bold hypothesis of a Madagascan origin at a very deep basal node within Hydaticus and multiple out-of-Madagascar dispersal events. This hypothesis needs to be tested with equally intense taxon sampling of mainland Africa as for Madagascar.

Taxonomic revision of Madagascan Rhantus (Coleoptera, Dytiscidae, Colymbetinae) with an emphasis on Manjakatompo as a conservation priority.

We review the diving-beetle genus Rhantus Dejean of Madagascar (Coleoptera, Dytiscidae, Colymbetinae) based on museum collection holdings and recently collected expedition material. Both morphology and DNA is used to test species boundaries, in particular whether newly collected material from the Tsaratanana mountains in the north represent a new species or are conspecific with Rhantus manjakatompo Pederzani and Rocchi 2009, described based on a single male specimen from the central Ankaratra mountains. DNA of the holotype of R. manjakatompo was successfully extracted in a non-destructive way and sequenced. The general mixed Yule coalescent model applied to an ultrametric tree constructed from mitochondrial cytochrome c oxidase subunit I (COI) sequence data delimited three species. Morphological characters supported the same species unambiguously. We therefore recognise three species of Rhantus to occur in Madagascar: R. latus (Fairmaire, 1869), R. bouvieri Régimbart, 1900 and R. manjakatompo Pederzani and Rocchi, 2009. All three species are endemic to Madagascar and restricted to the highlands of the island. Rhantusstenonychus Régimbart, 1895, syn. n., is considered a junior synonym of R. latus. We designate lectotypes for R. bouvieri and R. goudoti Sharp, 1882, the latter a junior synonym of R. latus. We provide descriptions, a determination key, SEM-images of fine pronotal and elytral structures, distribution maps, habitus photos, and illustrations of male genitalia and pro- and mesotarsal claws. We discuss the role of the Manjakatompo forest as a refugium for Madagascan Rhantus diversity and other endemics of the montane central high plateau.