Sexual dimorphism and phylogenetic position of Chilodendron (Coleoptera: Curculionidae: Scolytinae) – a long isolated lineage endemic to Madagascar

Chilodendron Schedl, 1953 is resurrected as a valid genus based on Chilodendron planicolle Schedl, 1953. This is the only representative of the tribe Hylesinini Erichson, 1836 found on Madagascar and a molecular phylogenetic analysis of several genes supports a position separate from Hylesinopsis Eggers, 1920 and other putatively close relatives. It is likely that Chilodendron is the oldest living lineage of bark beetles on Madagascar and possibly originated in the late Cretaceous not long after the separation of Madagascar from the Indian subcontinent.publishedVersio

Molecular and morphological revision of Afrotropical Hypoborini (Coleoptera: Curculionidae: Scolytinae) revealed novel bark beetle taxa with narrow geographical distributions

Species in the bark beetle tribe Hypoborini Nüsslin, 1912 occur in dead twigs and branches, mainly in dry forest. The Afrotropical fauna previously included ten species in five genera. A taxonomic revision based on molecular and morphological data supports the description of three new genera and seven new species, and the creation of a new subtribe Xerasiborina Jordal, subtrib. n. in order to take account of the difference between crested and non-crested (elytral base) hypoborines. The new subtribe includes Xerasiborus Jordal, gen. n., Nisiborus Jordal, gen. n. and tentatively Glochiphorus Strohmeyer, 1910. Hypoborina in the Afrotropical region includes Dacryostactus Schaufuss, 1905, Styracoptinus Wood, 1962, Afrotrypetus Bright, 1982 stat. res., and Corditarsus Jordal, gen. n., with Hypoborus Erichson, 1836 and Liparthrum Wollaston, 1854 as geographically close members in the warm Palearctic. New species described are Xerasiborus quadrituberculatus Jordal, sp. n., Xerasiborus bituberculatus Jordal, sp. n., Xerasiborus euphorbiae Jordal, sp. n. and Xerasiborus asperatus Jordal, sp. n., all from Madagascar, Xerasiborus zambesianus Jordal, sp. n. from Tanzania, Nisiborus schaufussi Jordal, sp. n. from Madagascar and Afrotrypetus capensis Jordal, sp. n. from South Africa. New combinations include Nisiborus hylesiniformis (Schedl, 1961), comb. n. (from Cryphyophthorus Schedl, 1953), Corditarsus australis (Schedl, 1975) comb. n. (from Liparthrum), Corditarsus tanganyikaensis (Schedl, 1972) comb. n. (from Hypoborus) and Afrotrypetus euphorbiae Bright, 1981 comb. res. (from Styracoptinus). Three genera were removed from Hypoborini: Chaetophloeus LeConte, 1876 and placed in Chaetophloeini Jordal, trib. n., Zygophloeus Schedl, 1958 in Hylesinini Erichson, 1836 and Cryphyophthorus Schedl, 1953 as a genus incertae sedis. Biogeographical analyses indicate an early Palaeocene origin of Hypoborini, with an ancestral area split between Asia/Africa and Madagascar. Only a single colonization of Madagascar occurred, with a single recolonization of the African mainland. The more species-rich Mediterranean and Macaronesian radiation in Liparthrum occurred later in the Oligocene, most likely prior to the origin of the Atlantic islands.publishedVersio

The smallest known species of Afrotropical Scolytoplatypus Schaufuss (Curculionidae, Scolytinae) - with unique features and an isolated phylogenetic position

Recent flight intercept trapping in Gabon provided four female specimens of a new species of Scolytoplatypus Schaufuss with several unusual features. It is the smallest known Afrotropical species found to date (1.6 mm long), it has unusually long antennal clubs, and some characters show resemblance to small Asian species or to the Malagasy genus Remansus Jordal. Genetic data from four genes nevertheless place this species as the sister lineage to all other Afrotropical species where it forms an isolated position corresponding to deviant morphological features.publishedVersio

Revision of the genus Phloeoditica Schedl - with description of two new genera and two new species in Phloeosinini (Coleoptera, Curculionidae, Scolytinae)

The genus Phloeoditica Schedl currently includes four species from Southeast Asia. These species vary substantially in important morphological characters and indicate the existence of multiple genera for these species. A revision based on morphological and in part molecular data resulted in the transfer of Phloeoditica setosa to Pseudoxylechinus the erection of a new genus Asiophilus for Phloeoditica phloeosinoides and a new species Asiophilus macropunctatus from Vietnam. Another new genus with affinities to Phloeoditica is described based on the new species Microditica uniseriata from Thailand. The new genera are included in a revised key to the tribe Phloeosinini.publishedVersio

A phylogenetic and taxonomic assessment of Afrotropical Micracidini (Coleoptera, Scolytinae) reveals a strong diversifying role for Madagascar

Afrotropical bark beetle genera in the tribe Micracidini are revised and an identification key provided. The new classification is based on phylogenetic analyses of five molecular markers (COI, EF-1α, 28S, PABP1, CAD) in combination with morphological characters. Five new genera are erected and one genus synonymized, resulting in a total of 11 valid genera: Lanurgus Eggers, 1920, Traglostus Schedl, 1938, Pseudomicracis Eggers, 1920 (=Saurotocis Wood, 1984 syn. nov.), Phloeocurus Wood, 1984, Afromicracis Schedl, 1959, Dendrochilus Schedl, 1959, Neomicracis Jordal gen. nov., Leiomicracis Jordal gen. nov., Diplotrichus Jordal gen. nov., Pseudolanurgus Jordal gen. nov., Microlanurgus Jordal gen. nov. The following new species are described to be included in the new genera: Leiomicracis aurea Jordal sp. nov., Neomicracis squamigera Jordal sp. nov., both from Tanzania, and Microlanurgus bicolor Jordal sp. nov. and Microlanurgus ater Jordal sp. nov., from Madagascar. The following new synonyms and new combinations are proposed: Afromicracis dubius (Schedl, 1950) (=Afromicracis angolensis Schedl, 1962 syn. nov.), Afromicacis elongatulus (Schedl, 1977) comb. nov., Afromicracis jasminiae (Schedl 1957) comb. nov. (=Dendrochilus mikaniae Schedl 1957 syn. nov.), Afromicracis robustus (Schedl 1957) comb. nov. (=Dendrochilus arundinarius Schedl 1957 syn. nov., =Hypothenemus bambusae Browne, 1970 syn. nov., =Dendrochilus filum Schedl, 1977 syn. nov.) (all from Dendrochilus), Afromicracis setifer (Schedl 1957) comb. nov. (Mimiocurus), Lanurgus longipilis (Schedl, 1958) comb. nov., Lanurgus pubescens (Schedl, 1961) comb. nov. (both from Traglostus), Diplotrichus catenatus (Schedl, 1953) comb. nov., Diplotrichus elongatus (Schedl, 1950) comb. nov., Diplotrichus euphorbia (Schedl, 1961) comb. nov., Diplotrichus gracilis (Schedl, 1958) comb. nov., Diplotrichus minor (Schedl, 1950) comb. nov (=Lanurgus frontalis Schedl, 1953 syn. Nov.), Diplotrichus obesus (Schedl, 1953) comb. nov., Diplotrichus pygmaeus (Schedl, 1965) comb. nov., Diplotrichus rugosipes (Schedl, 1961) comb. nov., Diplotrichus subdepressus (Schedl, 1965) comb. nov., Diplotrichus widdringtoniae (Schedl, 1962) comb. nov. (all from Lanurgus), Diplotrichus ignotus (Schedl, 1965) comb. nov. (Pseudomicracis), Pseudolanurgus harunganae (Schedl, 1961) comb. nov. (=Lanurgus cribrellus Schedl, 1965 syn. nov.), Pseudolanurgus bugekeae (Schedl, 1957) comb. nov. (both from Pseudomicracis), Pseudolanurgus minutissimus (Schedl, 1961) comb. nov. (Lanurgus), Pseudomicracis dispar (Schedl, 1961) comb. nov., Pseudomicracis tomicoides (Schedl, 1961) comb. nov. (both from Saurotocis). The following taxa were transferred to genera in other tribes: Acanthotomicus intermedius (Schedl, 1977) comb. nov., Xylocleptes villiersi (Lepesme, 1942) comb. nov. (both from Dendrochilus); Eidophelus agnathus (Schedl, 1942) comb. nov., and Eidophelus ciliatipennis (Schedl, 1979) comb. nov. (all from Miocryphalus). The following five species were included in Karlsenius gen. nov. (Trypophloeini): Karlsenius klainedoxae (Schedl, 1957) comb. nov., Karlsenius nitidum (Schedl, 1965) comb. nov., Karlsenius nigrinum (Schedl, 1957) comb. nov., and Karlsenius attenuatus (Eggers, 1935) comb. nov. (from Miocryphalus), and Karlsenius ghanaensis (Schedl, 1977) comb. nov. (from Eidophelus). A time-tree and biogeographical analysis suggested that Madagascar was colonized only once in Micracidini, from East Africa soon after the origin of the tribe in late Cretaceous. Multiple re-colonisations from Madagascar to the mainland have contributed to further diversification of a tribe which is otherwise highly restricted in geographical distribution.publishedVersio

Ancient diversity of afrotropical Microborus: three endemic species - not one widespread

The primarily Neotropical genus Microborus Blandford is represented with three species in Africa and Madagascar. The previously recorded species from this region, M. boops Blandford, is a Neotropical species restricted to Central America and is likely not found in the Afrotropics. The previously recognised species in western parts of Africa is M. camerunus (Eggers) and is resurrected from synonymy under M. boops. Molecular and morphological data revealed a second species of this complex in Madagascar, M. brevisetosus Jordal. Another new species, M. angustus Jordal, co-occurs with M. camerunus in Cameroon. Substantial genetic divergence indicate that Microborus was established in the Afrotropical region long before human transport across oceans. A key to Afrotropical species is provided.publishedVersio

Deep phylogenetic divergence between Scolytoplatypus and Remansus, a new genus of Scolytoplatypodini from Madagascar (Coleoptera, Curculionidae, Scolytinae)

Scolytoplatypodini Blandford is a monotypic tribe of ambrosia beetles found in Asia, Madagascar and Africa. Only three species are currently known from Madagascar and four additional species are here described as new to science. Phylogenetic analyses of morphological and molecular data revealed that four of the seven endemic species are deeply separated from all other species by genetic and distinct morphological characters and therefore placed in a new genus Remansus Jordal. The split between this ancient lineage and Scolytoplatypus Schaufuss was estimated to approximate Palaeocene age (63 Ma), extending the minimum age of ambrosia feeding for this tribe to the beginning of the Palaeocene‒Eocene thermal maximum (PETM). In addition to the ancient origin of Remansus in Madagascar during the Palaeocene, a second origin occurred in Scolytoplatypus no more than 13 Ma. A geographical origin of the latter in South-Eastern Africa was unequivocally inferred from the phylogenies.publishedVersio

Integrated Taxonomic Revision of Afrotropical Xyleborinus (Curculionidae: Scolytinae) Reveals High Diversity After Recent Colonization of Madagascar

The ambrosia beetle genus Xyleborinus Reitter, 1913 is particularly species rich in Madagascar where the genus exhibits extraordinary morphological variation not seen elsewhere. This study provides the first detailed molecular phylogeny of the genus based on COI, 28S, and CAD gene fragments. Biogeographical and taxonomic hypotheses were tested for the Afrotropical fauna with a particular focus on the Malagasy radiation. Analyses revealed a single colonization of Madagascar no earlier than 8.5–11.0 Ma, indicating an extraordinary recent radiation on the island which has given rise to at least 32 species. Two recolonization events of the African mainland were strongly supported by the molecular data, with several other intraspecific dispersals to the mainland inferred from species distributions. A taxonomic re-evaluation of all Afrotropical Xyleborinus resulted in several taxonomic changes. We found that morphological differences associated with COI divergence higher than 7% indicated different species. Twelve new species are described: Xyleborinus castriformis Eliassen & Jordal, sp. nov., Xyleborinus clivus Eliassen & Jordal, sp. nov., Xyleborinus concavus Eliassen & Jordal, sp. nov., Xyleborinus coronatus Eliassen & Jordal, sp. nov., Xyleborinus diadematus Eliassen & Jordal, sp. nov., Xyleborinus laevipennis Eliassen & Jordal, sp. nov., Xyleborinus magnispinosus Eliassen & Jordal, sp. nov., Xyleborinus margo Eliassen & Jordal, sp. nov., Xyleborinus ntsoui Eliassen & Jordal, sp. nov., Xyleborinus singularis Eliassen & Jordal, sp. nov., Xyleborinus tuberculatus Eliassen & Jordal, sp. nov., and Xyleborinus turritus Eliassen & Jordal, sp. nov., all from Madagascar. New synonyms are proposed for Xyleborinus aemulus (Wollaston, 1869) [=Xyleborinus spinifer (Eggers, 1920)], Xyleborinus andrewesi (Blandford, 1896) [=Xyleborinus mimosae (Schedl, 1957)], Xyleborinus dentellus (Schedl, 1953) [=Xyleborinus forcipatus (Schedl, 1957)], Xyleborinus octospinosus (Eggers, 1920) [=Xyleborinus mitosomipennis (Schedl, 1953)], and Xyleborinus similans (Eggers, 1940) [=Xyleborinus sclerocaryae (Schedl, 1962)]. Two species were given new status: Xyleborinus profundus (Schedl, 1961) is elevated from subspecies of Xyleborinus aduncus (Schedl, 1961), and Xyleborinus mitosomus (Schedl, 1965) is reinstated from its previous synonymy with Xyleborinus spinosus (Schaufuss, 1891). Xyleborus gracilipennis Schedl 1957 is reverted to its original genus, and a similar status is confirmed for Xyleborus collarti Eggers 1932. The number of taxonomically valid Xyleborinus species in the Afrotropical region is now 47, which includes 3 adventive species. Revised diagnoses for all species and a key for species identification are provided.publishedVersio

New molecular markers resolve the phylogenetic position of the enigmatic wood-boring weevils Platypodinae (Coleoptera: Curculionidae)

The precise phylogenetic position of the weevil subfamily Platypodinae continues to be one of the more contentious issues in weevil systematics. Morphological features of adult beetles and similar ecological adaptations point towards a close relationship with the wood boring Scolytinae, while some recent molecular studies and larval morphology have indicated a closer relationship to Dryophthorinae. To test these opposing hypotheses, a molecular phylogeny was reconstructed using 5,966 nucleotides from ten gene fragments. Five of these genes are used for the first time to explore beetle phylogeny, i.e. the nuclear protein coding genes PABP1, UBA5, Arr2, TPI, and Iap2, while five markers have been used in earlier studies (28S, COI, CAD, ArgK, and EF-1α). Bayesian, maximum likelihood and parsimony analyses of the combined data strongly support a monophyletic Curculionidae (the advanced weevils with geniculate antennae), where Brachycerinae, Platypodinae, and Dryophthorinae formed the earliest diverging groups. Dryophthorinae and core Platypodinae were sister groups with high support, with the contentious genera Mecopelmus Blackman, 1944 and Coptonotus Chapuis, 1873 placed elsewhere. Other lineages of wood boring weevils such as Scolytinae, Cossoninae, and Conoderinae were part of a derived, but less resolved, clade forming the sister group to Entiminae. Resolution among major curculionid subfamilies was ambiguous, emphasizing the need for large volumes of data to further improve resolution in this most diverse section of the weevil tree.publishedVersio

Origin and evolution of fungus farming in wood-boring Coleoptera – a palaeontological perspective

Insect–fungus mutualism is one of the better-studied symbiotic interactions in nature. Ambrosia fungi are an ecological assemblage of unrelated fungi that are cultivated by ambrosia beetles in their galleries as obligate food for larvae. Despite recently increased research interest, it remains unclear which ecological factors facilitated the origin of fungus farming, and how it transformed into a symbiotic relationship with obligate dependency. It is clear from phylogenetic analyses that this symbiosis evolved independently many times in several beetle and fungus lineages. However, there is a mismatch between palaeontological and phylogenetic data. Herein we review, for the first time, the ambrosia system from a palaeontological perspective. Although largely ignored, families such as Lymexylidae and Bostrichidae should be included in the list of ambrosia beetles because some of their species cultivate ambrosia fungi. The estimated origin for some groups of ambrosia fungi during the Cretaceous concurs with a known high diversity of Lymexylidae and Bostrichidae at that time. Although potentially older, the greatest radiation of various ambrosia beetle lineages occurred in the weevil subfamilies Scolytinae and Platypodinae during the Eocene. In this review we explore the evolutionary relationship between ambrosia beetles, fungi and their host trees, which is likely to have persisted for longer than previously supposed.publishedVersio