The genus Trigonopterus Fauvel, 1862 is highly diverse in Melanesia, the Moluccas, and the Sunda Islands. Only one species, Trigonopterusfulvicornis (Pascoe, 1885) was so far recorded from Sulawesi. Based on focused field-work the fauna from Sulawesi and nearby islands is here revised. We redescribe T.allotopus Riedel newly recorded for Sulawesi and describe an additional 103 new species: T.abnormissp. n., T.adspersussp. n., T.ambangensissp. n., T.ampanensissp. n., T.analissp. n., T.arachnobassp. n., T.armipessp. n., T.artemissp. n., T.asterixsp. n., T.barbipessp. n., T.bonthainensissp. n., T.carinirostrissp. n., T.castaneipennissp. n., T.celebensissp. n., T.cirripessp. n., T.collarissp. n., T.costatulussp. n., T.curvipessp. n., T.crenulatussp. n., T.crickisp. n., T.darwinisp. n., T.ejaculatoriussp. n., T.fuscipessp. n., T.gracilipessp. n., T.hebertisp. n., T.hirsutussp. n., T.humilissp. n., T.hypocritasp. n., T.idefixsp. n., T.impressicollissp. n., T.incendiumsp. n., T.incognitussp. n., T.indigenussp. n., T.inhonestussp. n., T.invalidussp. n., T.jasminaesp. n., T.klabatensissp. n., T.kolakensissp. n., T.kotamobagensissp. n., T.laevigatussp. n., T.lamprossp. n., T.latipennissp. n., T.lompobattangensissp. n., T.luwukensissp. n., T.mahawuensissp. n., T.manadensissp. n., T.mangkutanensissp. n., T.matalibaruensissp. n., T.mesaisp. n., T.minahassaesp. n., T.moatensissp. n., T.modoindingensissp. n., T.nanussp. n., T.nitidulussp. n., T.obelixsp. n., T.ovalipunctatussp. n., T.ovatulussp. n., T.pagaranganensissp. n., T.palopensissp. n., T.paracollarissp. n., T.paupersp. n., T.pendolensissp. n., T.posoensissp. n., T.prismaesp. n., T.procurtussp. n., T.pseudallotopussp. n., T.pseudanalis, sp. n., T.pseudovatulussp. n., T.pseudovalipunctatussp. n., T.pseudofulvicornissp. n., T.pseudomanadensissp. n., T.pseudosimulanssp. n., T.pumilussp. n., T.rantepaosp. n., T.reticulatussp. n., T.rhombiformissp. n., T.rotundatussp. n., T.rotundulussp. n., T.rudissp. n., T.rufipessp. n., T.sampunensissp. n., T.sampuragensissp. n., T.satyrussp. n., T.scabripessp. n., T.scaphiformissp. n., T.scitulussp. n., T.selayarensissp. n., T.serripessp. n., T.seticnemissp. n., T.silvicolasp. n., T.squalidulussp. n., T.sulawesiensissp. n., T.suturatussp. n., T.tatorensissp. n., T.tenuipessp. n., T.tomohonensissp. n., T.torajasp. n., T.vicinussp. n., T.viduussp. n., T.volcanorumsp. n., T.wangiwangiensissp. n., T.watsonisp. n., and T.yodasp. n. All new species are authored by the taxonomist-in-charge, Alexander Riedel.

Wallace's Line, located in the heart of the Indo‐Australian archipelago, has historically been hypothesized to strongly inhibit dispersal. Taxa crossing this barrier are confronted with different biota of Asian or Australian origin, respectively, but the extent to which these conditions have affected the evolution of the colonizing lineages remains largely unknown. We examined the potential correlations of body size, lifestyle and biogeographical distribution in the weevil genus Trigonopterus. These beetles are highly diverse both on foliage and in litter east of Wallace's Line but occur exclusively in leaf litter in the west. Based on a comprehensive, dated phylogeny of 303 species, we inferred nine crossing events of Wallace's Line, all from east to west. Five previously foliage‐dwelling lineages changed their lifestyle to leaf litter habitats after crossing this barrier. Our results indicate that dispersal is not more likely in edaphic lineages, but rather that abiotic and/or biotic factors may be responsible for the exclusive leaf litter habitat of Trigonopterus in Sundaland. This includes differences in climate, and the different predatory faunas of Australia‐New Guinea, Wallacea and Sundaland. A mimicry complex in New Guinea with Trigonopterus species as presumable model may be of relevance in this context.

BackgroundTaxonomy and biogeography can benefit from citizen scientists. The use of social networking and open access cooperative publishing can easily connect naturalists even in more remote areas with in-country scientists and institutions, as well as those abroad. This enables taxonomic efforts without frontiers and at the same time adequate benefit sharing measures.New informationWe present new distribution and habitat data for diving beetles of Bali island, Indonesia, as a proof of concept. The species Hydaticus luczonicus Aubé, 1838 and Eretes griseus (Fabricius, 1781) are reported from Bali for the first time. The total number of Dytiscidae species known from Bali is now 34.

Mitochondrial genomes of twelve species of Trigonopterus weevils are presented, ten of them complete. We describe their gene order and molecular features and test their potential for reconstructing the phylogeny of this hyperdiverse genus comprising > 1,000 species. The complete mitochondrial genomes examined herein ranged from 16,501 bp to 21,007 bp in length, with an average AT content of 64.2% to 69.7%. Composition frequencies and skews were generally lower across species for atp6, cox1-3, and cob genes, while atp8 and genes coded on the minus strand showed much higher divergence at both nucleotide and amino acid levels. Most variation within genes was found at the codon level with high variation at third codon sites across species, and with lesser degree at the coding strand level. Two large non-coding regions were found, CR1 (between rrnS and trnI genes) and CR2 (between trnI and trnQ), but both with large variability in length; this peculiar structure of the non-coding region may be a derived character of Curculionoidea. The nad1 and cob genes exhibited an unusually high interspecific length variation of up to 24 bp near the 3′ end. This pattern was probably caused by a single evolutionary event since both genes are only separated by trnS2 and length variation is extremely rare in mitochondrial protein coding genes. We inferred phylogenetic trees using protein coding gene sequences implementing both maximum likelihood and Bayesian approaches, each for both nucleotide and amino acid sequences. While some clades could be retrieved from all reconstructions with high confidence, there were also a number of differences and relatively low support for some basal nodes. The best partition scheme of the 13 protein coding sequences obtained by IQTREE suggested that phylogenetic signal is more accurate by splitting sequence variation at the codon site level as well as coding strand, rather than at the gene level. This result corroborated the different patterns found in Trigonopterus regarding to A+T frequencies and AT and GC skews that also greatly diverge at the codon site and coding strand levels.