Two sympatric lineages of Australian Cnestus solidus share Ambrosiella symbionts but not Wolbachia.

Sympatric lineages of inbreeding species provide an excellent opportunity to investigate species divergence patterns and processes. Many ambrosia beetle lineages (Curculionidae: Scolytinae) reproduce by predominant inbreeding through sib mating in nests excavated in woody plant parts wherein they cultivate symbiotic ambrosia fungi as their sole source of nutrition. The Xyleborini ambrosia beetle species Cnestus solidus and Cnestus pseudosolidus are sympatrically distributed across eastern Australia and have overlapping morphological variation. Using multilocus sequencing analysis of individuals collected from 19 sites spanning their sympatric distribution, we assessed their phylogenetic relationships, taxonomic status and microbial symbionts. We found no genetic differentiation between individuals morphologically identified as C. solidus and C. pseudosolidus confirming previous suggestions that C. pseudosolidus is synonymous to C. solidus. However, within C. solidus we unexpectedly discovered the sympatric coexistence of two morphologically indistinguishable but genetically distinct lineages with small nuclear yet large mitochondrial divergence. At all sites except one, individuals of both lineages carried the same primary fungal symbiont, a new Ambrosiella species, indicating that fungal symbiont differentiation may not be involved in lineage divergence. One strain of the maternally inherited bacterial endosymbiont Wolbachia was found at high prevalence in individuals of the more common lineage but not in the other, suggesting that it may influence host fitness. Our data suggest that the two Australian Cnestus lineages diverged allopatrically, and one lineage then acquired Wolbachia. Predominant inbreeding and Wolbachia infection may have reinforced reproductive barriers between these two lineages after their secondary contact contributing to their current sympatric distribution.

Patterns of host tree use within a lineage of saproxlic snout-less weevils (Coleoptera: Curculionidae: Scolytinae: Scolytini).

The influence of plants in the diversification of herbivorous insects, specifically those that utilize moribund and dead hosts, is little explored. Host shifts are expected because the effectiveness of toxic secondary chemicals is lessened by decay of dead plants. Feeding on dead plants also releases herbivorous insect lineages from diversifying within a particular plant lineage. Thus, phylogenetic constraints on the herbivorous insect lineage imposed by the host plants are diminished and repeated patterns of species diversification in an association with unrelated host trees is hypothesized (i.e., taxon cycle). Scolytini, a diverse weevil tribe, specialize on many different dead and moribund plant taxa as a source of food. These species and their hosts offer an opportunity to examine the association between dead host plants and the extent of phylogenetic constraints. A phylogeny of the Scolytini was reconstructed with likelihood and Bayesian analyses of DNA sequence data from nuclear (28S, CAD, ArgK) and mitochondrial (COI) genes. Ancestral host usage and geography was reconstructed using likelihood criteria and conservation of host use was tested. Results supported a monophyletic Scolytini, Ceratolepis, Loganius, and a paraphyletic Scolytus, Camptocerus and Cnemonyx. Diversification of the Scolytini generally occurred well after their host taxa diversified and suggests a sequential evolution of host use. In this scenario the beetle imposes little selection pressure on the tree but the tree provides a platform for beetle evolution. Major changes in host tree use occurred during periods of global cooling associated with changes in beetle biogeography. Diversification of beetles occurred on common and widespread hosts and there was likely a single origination of conifer-feeding from angiosperm-feeding species during the early Pliocene and a radiation of beetle species from the Palearctic to the Nearctic. Overall, the observed patterns of Scolytini host use are conserved and are similar to those expected in a taxon pulse diversification. That is, after a host switch to an unrelated tree, the beetles diversify within the host plant lineage. The need to locate an ephemeral food resource, i.e., a dying tree, likely maintains host specificity once a host shift occurs. These findings suggest that characteristics of dead and moribund host plants (e.g. secondary chemicals) influence the diversification of these saproxlic weevils despite the reduction of selection pressures.

Phylogenomics clarifies repeated evolutionary origins of inbreeding and fungus farming in bark beetles (Curculionidae, Scolytinae).

Bark and ambrosia beetles (Curculionidae, Scolytinae) display a conspicuous diversity of unusual genetic and ecological attributes and behaviors. Reconstructing the evolution of Scolytinae, particularly the large and ecologically significant tribe Cryphalini (pygmy borers), has long been problematic. These challenges have not adequately been addressed using morphological characters, and previous research has used only DNA sequence data from small numbers of genes. Through a combination of anchored hybrid enrichment, low-coverage draft genomes, and transcriptomes, we addressed these challenges by amassing a large molecular phylogenetic dataset for bark and ambrosia beetles. The resulting DNA sequence data from 251 protein coding genes (114,276 bp of nucleotide sequence data) support inference of the first robust phylogeny of Scolytinae, with a special focus on the species rich tribe Cryphalini and its close relatives. Key strategies, including inbreeding mating systems and fungus farming, evolved repeatedly across Scolytinae. We confirm 12 of 16 hypothesized origins of fungus farming, 6 of 8 origins of inbreeding polygyny and at least 11 independent origins of a super-generalist host range. These three innovations are statistically correlated, but their appearance within lineages was not necessarily simultaneous. Additionally, the evolution of extreme host plant generalism often preceded, rather than succeeded, fungus farming. Of the high-diversity tribes of Scolytinae, only Xyleborini is monophyletic, Corthylini is paraphyletic and Cryphalini is highly polyphyletic. Cryphalini sensu stricto is part of a clade containing the genera Hypothenemus, Cryphalus and Trypophloeus, and the tribe Xyloterini. Stegomerus and Cryptocarenus (Cryphalini) are part of a clade otherwise containing all Corthylini. Several other genera, including Ernoporus and Scolytogenes (Cryphalini), make up a distantly related clade. Several of the genera of Cryphalini are also intermixed. For example, Cryphalus and Hypocryphalus are intermingled, as well as Ernoporicus, Ptilopodius and Scolytogenes. Our data are consistent with widespread polyphyly and paraphyly across Scolytinae and within Cryphalini, and provides new insights into the evolution of inbreeding mating systems and fungus farming in the species rich and ecologically significant weevil subfamily Scolytinae.

Globally distributed Xyleborus species reveal recurrent intercontinental dispersal in a landscape of ancient worldwide distributions.

BACKGROUND: Invasive species can have devastating effects on native ecosystems and therefore impose a significant threat to human welfare. The introduction rate of invasive species has accelerated dramatically in recent times due to human activity (anthropogenic effects), with a steadily growing pool of widespread tramp species. We present an in-depth analysis of four pantropical species of Xyleborus ambrosia beetles (Xyleborus volvulus, Xyleborus perforans, Xyleborus ferrugineus, and Xyleborus affinis) with similar ecology (fungus cultivation in dead wood), reproductive biology (permanent inbreeding) and genetic system (haplodiploidy). The unique combination of reproductive traits and broad host plant usage pre-adapts these beetles for colonizing of new areas. RESULTS: We found that all four species were broadly distributed long before human-assisted dispersal became common, and that the impact of anthropogenic effects varied among the species. For X. volvulus, X. perforans, and X. affinis there was evidence of ancient establishment in numerous regions, but also of abundant recent introductions into previously colonized areas. For X. ferrugineus, we found clear biogeographical structuring of old clades, but little evidence for recent successful introductions. CONCLUSIONS: Our results indicate that current human-aided transoceanic dispersal has strongly affected the genetic makeup of three of the species in this study. However, current biogeographical patterns of all four species are equally, if not more strongly, influenced by ancient establishment on different continents.

Bulk de novo mitogenome assembly from pooled total DNA elucidates the phylogeny of weevils (Coleoptera: Curculionoidea).

Complete mitochondrial genomes have been shown to be reliable markers for phylogeny reconstruction among diverse animal groups. However, the relative difficulty and high cost associated with obtaining de novo full mitogenomes have frequently led to conspicuously low taxon sampling in ensuing studies. Here, we report the successful use of an economical and accessible method for assembling complete or near-complete mitogenomes through shot-gun next-generation sequencing of a single library made from pooled total DNA extracts of numerous target species. To avoid the use of separate indexed libraries for each specimen, and an associated increase in cost, we incorporate standard polymerase chain reaction-based "bait" sequences to identify the assembled mitogenomes. The method was applied to study the higher level phylogenetic relationships in the weevils (Coleoptera: Curculionoidea), producing 92 newly assembled mitogenomes obtained in a single Illumina MiSeq run. The analysis supported a separate origin of wood-boring behavior by the subfamilies Scolytinae, Platypodinae, and Cossoninae. This finding contradicts morphological hypotheses proposing a close relationship between the first two of these but is congruent with previous molecular studies, reinforcing the utility of mitogenomes in phylogeny reconstruction. Our methodology provides a technically simple procedure for generating densely sampled trees from whole mitogenomes and is widely applicable to groups of animals for which bait sequences are the only required prior genome knowledge.

Molecular phylogeny and biogeography of the weevil subfamily Platypodinae reveals evolutionarily conserved range patterns.

Platypodinae is a peculiar weevil subfamily of species that cultivate fungi in tunnels excavated in dead wood. Their geographical distribution is generally restricted, with genera confined to a single continent or large island, which provides a useful system for biogeographical research. This study establishes the first detailed molecular phylogeny of the group, with the aim of testing hypotheses on classification, diversification, and biogeography. A phylogeny was reconstructed based on 3648 nucleotides from COI, EF-1α, CAD, ArgK, and 28S. Tree topology was well resolved and indicated a strong correlation with geography, more so than predicted by previous morphology-based classifications. Tesserocerini was paraphyletic, with Notoplatypus as the sister group to a clade consisting of three main lineages of Tesserocerini and the recently evolved Platypodini. Austroplatypus formed the sister group to all remaining Platypodini and hence confirmed its separate status from Platypus. The Indo-Australian genera of Platypodini were strikingly paraphyletic, suggesting that the taxonomy of this tribe needs careful revision. Ancestral-area reconstructions in Lagrange and S-DIVA were ambiguous for nodes roughly older than 80 Ma. More recent events were firmly assessed and involved post-Gondwanan long-distance dispersal. The Neotropics was colonized three times, all from the Afrotropical region, with the latest event less than 25 Ma that included the ancestor of all Neotropical Platypodini.

An integrated taxonomic revision of Ctonoxylon (Coleoptera, Curculionidae, Scolytinae) reveals new Malagasy species originating from multiple recent colonisations of the island.

Ctonoxylon is a strictly Afrotropical genus of bark beetles breeding under bark of rainforest trees and lianas. A taxonomic revision of the genus included a molecular phylogenetic analysis of ten species based on three gene fragments and was compared to a morphology-based tree topology for all 24 currently recognised species. Four species are described as new to science: Ctonoxylontorquatum, sp. nov., Ctonoxylontuberculatum, sp. nov., Ctonoxylonquadrispinum, sp. nov., all from Madagascar, and Ctonoxylonpilosum, sp. nov. from Cameroon. Ctonoxylonhirsutum Hagedorn, 1910, stat. rev. is resurrected from synonymy with C.flavescens Hagedorn, 1910, and C.atrum Browne, 1965 stat. rev. from its synonymy with C.methneri Eggers, 1922 (as C.hamatum Schedl, 1941). The following species have new synonymies suggested: Ctonoxylonfestivum Schedl, 1941 (= C.dentigerum Schedl, 1941, syn. nov.), C.methneri Eggers, 1922 (= C.hamatum Schedl, 1941, syn. nov., = C.griseum Schedl, 1941, syn. nov.), C.montanum Eggers, 1922 (= C.longipilum Eggers, 1935, syn. nov., = C.nodosum Eggers, 1940, syn. nov.), C.camerunum Hagedorn, 1910 (= C.conradti Schedl, 1939, syn. nov.), and C.spinifer Eggers, 1920 (= C.setifer Eggers, 1920, syn. nov.). New country records are noted for C.festivum (Tanzania), C.flavescens (Uganda), C.camerunum (Liberia), C.crenatum Hagedorn, 1910 (Democratic Republic of the Congo), C.spathifer Schedl, 1941 (Ghana), C.atrum (Cameroon), and C.spinifer (Madagascar), with patterns in distribution and colonisation of Madagascar discussed. An identification key with pictures of all species is provided.

Morphological Ontogeny, Ecology, and Biogeography of Fuscozetes fuscipes (Acari, Oribatida, Ceratozetidae).

The systematic status of Fuscozetes Sellnick, 1928, is not clear in the literature. Therefore, the morphological ontogeny of F. fuscipes (C.L. Koch, 1844), the type species of this genus, was investigated and compared with its congeners in this study, and a new diagnosis of Fuscozetes is given. The juveniles of F. fuscipes are light brown, with a brown prodorsum, sclerites, epimeres, and legs. In all juveniles, a humeral organ and a humeral macrosclerite are present. The gastronotum of the larva has 12 pairs of setae (h3 is present), whereas the nymphs have 15 pairs. In the larva, the gastronotal shield is weakly developed, and most gastronotal setae are short except for a slightly longer h2. Most of the gastronotal setae are inserted on the microsclerites except for h3, and several other macrosclerites and many microsclerites are present on the hysterosoma. In the nymphs, the gastronotal shield is well developed, with 10 pairs of setae (d-, l-, and h-series, and p1), and setae p2 and p3 are located on a large posteroventral macrosclerite. In all the instars, femora I and II are oval in cross-section, without a large ventral carina. Mitochondrial COI sequence data revealed a deep split between the Nearctic and Palearctic populations of F. fuscipes, and a less, but significant, divergence within each continent. These strong geographical barriers were contrasted with multiple cases of shared haplotypes over long distances in the Palearctic, indicating high migration rates in modern times.

New species and records of Scolytodes (Coleoptera, Curculionidae: Scolytinae) from South America.

Seventeen new species of Scolytodes Ferrari are described from Venezuela, Ecuador, Peru, Bolivia and Argentina: Scolytodes cenchros, S. concavifrons, S. conpunctus, S. fraterniatratus, S. frontocarinatus, S. solarius and S. trigonus from Cecropia leafstalks; S. pascopomus from a fruit husk; S. obovatus, S. clusiaphilus, S. clusiapraelatus and S. uniseriatus from Clusia litter sifting; S. grossepunctatus and S. fulvus from general litter sifting; and S. inusitatus, S. sagittarius and S. sus collected by flight intercept traps. The synonymy of S. imitans and S. nitidissimus is confirmed. Additional South American records are given for S. chapuisi (Ecuador), S. interpunctatus (Peru), S. maurus (Ecuador), and S. suspectus (Ecuador), all taken from Cecropia leafstalks, and S. similis (Peru) and S. unipunctatus (Bolivia).

The red-listed species Thamnurgus rossicus in East Europe is a synonym of the rare Central European species, T. petzi (Curculionidae: Scolytinae).

The taxonomic status of Thamnurgus rossicus was evaluated with respect to the morphologically similar T. petzi using genetic markers. Nucleotide data from the mitochondrial COI gene revealed 2.4% variation between the European Alps and Russian steppe populations. The two nuclear DNA markers CAD and EF1á were identical across populations. In view of their similar morphology, genetic composition, and the partial overlap in host plant preferences (Ranunculaceae: Aconitum and Delphinium), T. rossicus is placed in synonymy with T. petzi.

Molecular phylogeny of bark and ambrosia beetles reveals multiple origins of fungus farming during periods of global warming.

BACKGROUND: Fungus farming is an unusual life style in insects that has evolved many times in the wood boring weevils named 'ambrosia beetles'. Multiple occurrences of this behaviour allow for a detailed comparison of the different origins of fungus farming through time, its directionality, and possible ancestral states. We tested these hypotheses with a phylogeny representing the largest data set to date, nearly 4 kb of nucleotides from COI, EF-1α, CAD, ArgK, 28S, and 200 scolytine taxa. RESULTS: Phylogenetic analyses using Bayesian or parsimony approaches placed the root of Scolytinae close to the tribe Scolytini and Microborus, but otherwise indicated low resolution at older nodes. More recent clades were well resolved, including ten origins of fungus farming. There were no subsequent reversals to bark or phloem feeding in the fungus farming clades. The oldest origin of fungus farming was estimated near 50 Ma, long after the origin of Scolytinae (100-120 Ma). Younger origins included the species rich Xyleborini, dated to 21 Ma. Sister group comparisons and test of independence between traits indicated that neither gregarious larval feeding nor regular inbreeding by sibling mating was strongly correlated with the origin of fungus farming. CONCLUSION: Origins of fungus farming corresponded mainly with two periods of global warming in the Cenozoic era, which were characterised by broadly distributed tropical forests. Hence, it seems likely that warm climates and expanding tropical angiosperm forests played critical roles in the successful radiation of diverse fungus farming groups. However, further investigation will likely reveal additional biological factors that promote fungus farming.

The strongly dimorphic bark beetle genus Pseudomicracis (Coleoptera, Scolytinae) in Madagascaran integrated taxonomic revision.

The largely Malagasy bark beetle genus Pseudomicracis Eggers, 1920 is revised based on molecular data and morphological studies. Because the type species P. elsae Eggers, 1920 from Tanzania has no intact type material, the diagnosis is fixed using an auxiliary species, P. madagascariensis (Schedl, 1961), which is typical for the genus and supports the original description of P. elsae. Six new species are described from Madagascar: P. atra Jordal, sp. nov., P. coronata Jordal, sp. nov., P. lauricola Jordal, sp. nov., P. pilosa Jordal, sp. nov., P. verrucosa Jordal, sp. nov., and P. vitrioculata Jordal, sp. nov. Mimiocurus camerunus (Hagedorn, 1909) has no existing type material and is transferred from Pseudomicracis based on Hagedorns illustrations of the antenna and protibia. New distributional and host records are given for P. dispar (Schedl, 1961), P. difficilis (Schedl, 1965) and P. madagascariensis (Schedl, 1961). A molecular phylogenetic analysis included 8 of 12 known species, documenting a strongly supported clade of Pseudomicracis species, but with highly uncertain internal relationships. A key and photographs to all Malagasy species are provided.

The age and phylogeny of wood boring weevils and the origin of subsociality.

A large proportion of the hyperdiverse weevils are wood boring and many of these taxa have subsocial family structures. The origin and relationship between certain wood boring weevil taxa has been problematic to solve and hypotheses on their phylogenies change substantially between different studies. We aimed at testing the phylogenetic position and monophyly of the most prominent wood boring taxa Scolytinae, Platypodinae and Cossoninae, including a range of weevil outgroups with either the herbivorous or wood boring habit. Many putatively intergrading taxa were included in a broad phylogenetic analysis for the first time in this study, such as Schedlarius, Mecopelmus, Coptonotus, Dactylipalpus, Coptocorynus and allied Araucariini taxa, Dobionus, Psepholax, Amorphocerus-Porthetes, and some peculiar wood boring Conoderini with bark beetle behaviour. Data analyses were based on 128 morphological characters, rDNA nucleotides from the D2-D3 segment of 28S, and nucleotides and amino acids from the protein encoding gene fragments of CAD, ArgK, EF-1α and COI. Although the results varied for some of the groups between various data sets and analyses, one may conclude the following from this study: Scolytinae and Platypodinae are likely sister lineages most closely related to Coptonotus; Cossoninae is monophyletic (including Araucariini) and more distantly related to Scolytinae; Amorphocerini is not part of Cossoninae and Psepholax may belong to Cryptorhynchini. Likelihood estimation of ancestral state reconstruction of subsociality indicated five or six origins as a conservative estimate. Overall the phylogenetic results were quite dependent on morphological data and we conclude that more genetic loci must be sampled to improve phylogenetic resolution. However, some results such as the derived position of Scolytinae were consistent between morphological and molecular data. A revised time estimation of the origin of Curculionidae and various subfamily groups were made using the recently updated fossil age of Scolytinae (100 Ma), which had a significant influence on node age estimates.

An integrated taxonomic revision of Diplotrichus (Coleoptera, Scolytinae) supports a Malagasy origin and single colonisation of South Africa.

The Afrotropical genus Diplotrichus Jordal, 2021 is revised. Altogether 21 species are included in the genus, with 10 species described as new to science: Diplotrichus pilifrons Jordal, sp. nov., Diplotrichus medius Jordal, sp. nov., and Diplotrichus calvifrons Jordal, sp. nov. from South Africa, and Diplotrichus acutior Jordal, sp. nov., Diplotrichus falcatus Jordal, sp. nov., Diplotrichus pulchellus Jordal, sp. nov., Diplotrichus granulatus Jordal, sp. nov., Diplotrichus tuberculatus Jordal, sp. nov., Diplotrichus robustus Jordal, sp. nov., and Diplotrichus plenus Jordal, sp. nov., all from Madagascar. A molecular phylogenetic analysis based on five gene fragments (COI, EF-1a, CAD, PABP1, 28S) resulted in four major clades, with South African species nested within a grade of Malagasy species, supporting a more recent colonisation of the African mainland around the early Miocene.

The mainly South African genus Lanurgus revised (Coleoptera, Scolytinae).

The Afrotropical and mainly southern African genus Lanurgus Eggers, 1920 is revised. Five new species are described from the Cape provinces in South Africa: Lanurgus beaveri, sp. nov., Lanurgus carinatus, sp. nov., Lanurgus jubatus, sp. nov., Lanurgus mattheei, sp. nov., and Lanurgus tsitsikammae, sp. nov. A molecular phylogenetic analysis of nine species revealed deep divergence between fairly morphologically similar species, with few clues on nested relationships within the genus. Photos and a key to all known species is presented.

New species and records of Pseudolanurgus (Coleoptera: Curculionidae, Scolytinae) from Tanzania and Madagascar.

The recently established genus Pseudolanurgus Jordal, 2021 included one species from Democratic Republic of the Congo and two from Madagascar. Two more species are here described as new to science: Pseudolanurgus mystax sp. nov. from the United Republic of Tanzania and Pseudolanurgus asperatus sp. nov. from Madagascar. A key to all five species is provided along with photos of all species.

Revision of Dendrochilus (Coleoptera, Scolytinae)-with description of two new species from Tanzania.

The genus Dendrochilus Schedl, 1963 is revised. Two new species are described from the Udzungwa Mountains in Tanzania. Dendrochilus tener sp. nov., and D. udzungwae sp. nov. are closely related with few morphological differences but are clearly separated by molecular data from four gene fragments. Together with the type species D. strombosiopsis Schedl, 1957 from Congo, the genus now includes three species. An identification key to species is provided.

Polyphyly of Xylosandrus Reitter inferred from nuclear and mitochondrial genes (Coleoptera: Curculionidae: Scolytinae).

The Xyleborina ambrosia beetle genus Xylosandrus contains 54 species, several of which are of economic importance. The monophyly of the genus was tested using a data set comprised of multiple gene loci: 28S rDNA; the mitochondrial gene cytochrome oxidase I (COI); and the nuclear genes arginine kinase (ArgK), rudimentary (CAD), and Elongation Factor 1alpha (EF-1alpha). The nuclear protein-coding genes CAD and ArgK were used for the first time in phylogenetics of Scolytinae. Analyses were performed using Parsimony and Bayesian optimality criteria. Our analyses included 43 specimens representing 15 Xylosandrus species and 20 species from Amasa, Anisandrus, Cnestus, Euwallacea and Xyleborus, and two species from the outgroup genus Coccotrypes. All analyses recovered a polyphyletic Xylosandrus. Several species of Xylosandrus were consistently placed in clades with the genera Anisandrus and Cnestus with high support values (100% bootstrap support). Among these, was the economically important invasive species X. mutilatus, which was consistently recovered as part of the "Cnestus" clade. In our analyses, both CAD and ArgK demonstrated phylogenetic utility across varying nodal depths. Despite the selection of genes with signals at complementary phylogenetic depths, the data set used herein did not resolve the phylogeny of Xylosandrus and related genera. Since the taxon sample available for molecular work represents only a fraction of Xylosandrus species, a complete revision that combines molecular and morphological data in a total evidence approach is recommended for the genus.

Molecular phylogeny and Holarctic diversification of the subtribe Calathina (Coleoptera: Carabidae: Sphodrini).

A molecular phylogeny of the subtribe Calathina was inferred from DNA sequence data from the mitochondrial cox1-cox2 region and the nuclear genes 28S and EF-1alpha. All lineages within Calathina from the Holarctic region were represented except for the monotypic subgenus Tachalus. Maximum Parsimony and Bayesian analyses of the combined data set showed that the subtribe is a monophyletic lineage that includes a single genus Calathus, where other taxa currently ranked as independent genera (Lindrothius, Synuchidius, Thermoscelis and Acalathus) are nested within this genus.Neocalathus and Lauricalathus, both subgenera of Calathus, were found to be polyphyletic and in need of taxonomic revision. The subtribe appears to have originated in the Mediterranean Basin and thereafter expanded into most parts of the Palearctic region, the Macaronesian archipelagos (at least five independent colonisation events), the Ethiopian highlands and the Nearctic region (at least two independent events).

Scolytodes Ferrari (Coleoptera, Scolytinae) from Ecuador: 40 new species, and a molecular phylogenetic guide to infer species differences.

The genus Scolytodes Ferrari is a highly diverse group of Neotropical bark beetles. Recent collecting by hand and canopy fogging in Ecuador produced many new records. Overlap in species composition between samples from the canopy and the ground was very low, and canopy fogging revealed the highest proportion of undescribed species. Altogether we report records for 55 species of Scolytodes from Ecuador, including 40 species new to science: Scolytodes pseudoatratus Jordal and Smith, sp. nov., Scolytodes latipes Jordal and Smith, sp. nov., Scolytodes sloanae Jordal and Smith, sp. nov., Scolytodes samamae Jordal and Smith, sp. nov., Scolytodes otongae Jordal and Smith, sp. nov., Scolytodes chaplini Jordal and Smith, sp. nov., Scolytodes projectus Jordal and Smith, sp. nov., Scolytodes lubricus Jordal and Smith, sp. nov., Scolytodes inordinatus Jordal and Smith, sp. nov., Scolytodes cancellatus Jordal and Smith, sp. nov., Scolytodes jubatus Jordal and Smith, sp. nov., Scolytodes abbreviatus Jordal and Smith, sp. nov., Scolytodes stramineus Jordal and Smith, sp. nov., Scolytodes teres Jordal and Smith, sp. nov., Scolytodes animus Jordal and Smith, sp. nov., Scolytodes pseudoanimus Jordal and Smith, sp. nov., Scolytodes bombycinus Jordal and Smith, sp. nov., Scolytodes bisetosus Jordal and Smith, sp. nov., Scolytodes horridus Jordal and Smith, sp. nov., Scolytodes virgatus Jordal and Smith, sp. nov., Scolytodes criniger Jordal and Smith, sp. nov., Scolytodes pseudocrassus Jordal and Smith, sp. nov., Scolytodes semicrassus Jordal and Smith, sp. nov., Scolytodes pseudolepidus Jordal and Smith, sp. nov., Scolytodes semilepidus Jordal and Smith, sp. nov., Scolytodes fortis Jordal and Smith, sp. nov., Scolytodes peniculus Jordal and Smith, sp. nov., Scolytodes tristis Jordal and Smith, sp. nov., Scolytodes chrysifrons Jordal and Smith, sp. nov., Scolytodes amictus Jordal and Smith, sp. nov., Scolytodes cnesinoides Jordal and Smith, sp. nov., Scolytodes maestus Jordal and Smith, sp. nov., Scolytodes vietus Jordal and Smith, sp. nov., Scolytodes echinus Jordal and Smith, sp. nov., Scolytodes rufifrons Jordal and Smith, sp. nov., Scolytodes arcuatus Jordal and Smith, sp. nov., Scolytodes validus Jordal and Smith, sp. nov., Scolytodes sparsus Jordal and Smith, sp. nov., Scolytodes lapillus Jordal and Smith, sp. nov., Scolytodes coronatus Jordal and Smith, sp. nov. We also provide the first description of the female and a new country record for Scolytodes grandis (Schedl, 1962) (=Scolytodes glaberrimus Wood, 1972 syn. nov.) and a redescription and new country record for Scolytodes pilifrons (Schedl, 1962). The total number of valid species is now 287. Additional new country records were established for Scolytodes acuminatus Wood, 1969, Scolytodes comosus Jordal and Kirkendall, 2019, Scolytodes costabilis Wood, 1974, Scolytodes glabrescens Wood, 1972, Scolytodes impressus Wood, 1969, Scolytodes nitidus (Eggers, 1928), Scolytodes striatus (Eggers, 1934), Scolytodes tucumani Wood, 2007, and from another Hexacolini genus, Pycnarthrum fulgidum Wood, 1977. The first molecular phylogeny for Scolytodes is provided and used primarily to guide the inference of species validity. Molecular data from COI, 28S and EF-1α revealed substantial genetic divergence between morphologically very similar but diagnosable species.