First Molecular Phylogeny Estimate of the Weevil Tribe Mecopini (Curculionidae: Conoderinae) Unveils its Polyphyletic Nature at the Tribal and Generic Level

© 2024 Academia Sinica, Taiwan Open Access First Molecular Phylogeny Estimate of the Weevil Tribe Mecopini (Curculionidae: Conoderinae) Unveils its Polyphyletic Nature at the Tribal and Generic Level Wei-Zhe Tseng1,2,*, Yun Hsiao3, Analyn Cabras4,5 , and Ren-Chung Cheng2,6,* 1Department of Life Science, National Taiwan Normal University, No. 88, Sec. 4, Tingzhou Rd., Taipei City 116059, Taiwan. *Correspondence: E-mail: [email protected] (Tseng) 2Department of Life Sciences, National Chung Hsing University, No. 145 Xingda Rd., South Dist., Taichung 40227, Taiwan 3Institute of Ecology and Evolutionary Biology, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 106, Taiwan. E-mail: [email protected] (Hsiao) 4Zoology Division, National Museum of Natural History, Malate, Manila, Philippines 5Invertebrate Research Laboratory, UResCom, Davao Oriental State University, City of Mati, Davao Oriental 8200, Philippines. E-mail: [email protected] (Cabras) 6Research Center for Global Change Biology, National Chung Hsing University, No. 145 Xingda Rd., South Dist., Taichung 40227, Taiwan. *Correspondence: E-mail: [email protected] (Cheng) Received 30 March 2024 / Accepted 9 September 2024 / Published 27 December 2024 Communicated by Jen-Pan Huang Mecopini has received limited attention since the last century, highlighting an important knowledge gap in its systematics and taxonomy. The morphological characteristics of several genera within this tribe contradict the widely accepted tribal diagnosis, suggesting the current classification is unsustainable. In this study, we examined mecopine specimens from Taiwan and the Philippines, reconstructed the first molecular phylogeny estimate for this obscure tribe, and examined type series of all described Pempheres Pascoe, Chirozetes (Chirozetes) arotes Heller and Chirozetes (Mesochirozetes) formosanus Heller, representing two subgenera within the genus Chirozetes Pascoe, to propose taxonomic acts on these genera. Our results reveal the polyphyletic relationships within Mecopini at both the tribal and generic levels. Based on the phylogenetic framework and morphological characters, we propose excluding Agametis Pascoe from this tribe and elevating the subgenus Mesochirozetes Heller to full generic status. We also designate lectotypes of Mesochirozetes formosanus Heller and two Pempheres species. Our study highlights the uncertainties of current classification of Mecopini, raising questions not only about the tribal composition but also the monophyly of genera within this tribe. Further studies are necessary to address these systematic issues, which may prompt a reevaluation and redefinition of this little-known tribe. Key words: Agametis, Chirozetes, Mesochirozetes, New synonym, New placement Citation: Tseng WZ, Hsiao Y, Cabras A, Cheng RC. 2024. First molecular phylogeny estimate of the weevil tribe Mecopini (Curculionidae: Conoderinae) unveils its polyphyletic nature at the tribal and generic level. Zool Stud 63:49. doi:10.6620/ZS.2024.63-49. BACKGROUND The tribe Mecopini Lacordaire, 1866 (Curculionidae: Conoderinae) comprises 22 genera and 139 described species exclusively inhabiting tropical and subtropical areas across the Oriental, Palearctic, and Ethiopian regions (Marshall 1941; Alonso-Zarazaga and Lyal 1999; Alonso-Zarazaga et al. 2024). Among these, Agametis Pascoe, Chirozetes Pascoe, Mecopus Schönherr, and Phylaitis Pascoe exhibit a disproportionately high species diversity, harboring 92 of the described mecopine species. In Zoological Studies 63:49 (2024) doi:10.6620/ZS.2024.63-49 1 © 2024 Academia Sinica, Taiwan contrast, eight genera and one subgenus are monotypic, most of which are known only from the original description without further records, indicating a lack of comprehensive taxonomic work on Mecopini. In terms of morphological characteristics, mecopine species, similar to other conoderines, are characterized by large eyes nearly occupying the entire heads (Kojima and Lyal 2002). They exhibit a preference for fallen timber in open environments and are usually active under the direct sunlight (Pascoe 1871; Lyal 1986). It is noteworthy that some mecopine species display distinct fly-mimic behaviors similar to those conoderine weevils observed in the Americas (Lyal 1986; Anzaldo et al. 2020). Despite their unique habitat preferences and behavior, these weevils have received limited attention by entomologists for a long time, leaving aspects of their biology, behavior, and systematics largely unexplored. Lacordaire (1866) established the tribe Zygopides and delineated it into two distinct geographical sections: Section I, exclusive to tropical America, and Section II, spanning Africa, the East Indies, and Polynesia. He further proposed the Mecopides as a subgroup within Section II, encompassing the genera Mecopus and Macrobamon Lacordaire (= Odoacis Pascoe). Pascoe (1870) subsequently elevated Zygopides to subfamilial status and incorporated Mecopus, Chirozetes, Agametis and Macrobamon into the Mecopides. Over the ensuing six decades, Mecopini received considerable attention, with the establishment of 16 out of the 22 described genera and description of a majority of named species (Pascoe 1871; Heller 1894 1898 1915 1922 1924 1929 1931; Hustache 1920 1921 1931). The tribal placement of these taxa remained unspecified until Hustache (1934) provided the first catalog, listing twenty-three genera in this tribe and thereby bringing clarity to the generic composition of Mecopini. However, since Hustache’s work, Mecopini has received limited attention up to the present. Marshall (1939) treated Heurippa Pascoe as a junior synonym of Synophthalmus Lacordaire (= Phytophilus Schönherr), automatically reassigning it to the tribe Coryssomerini. Two years later, Marshall (1941) recognized Pempherulus Marshall from Pempheres Pascoe. The generic composition of Mecopini remained unchanged for several decades until Wibmer and O'Brien (1986) transferred Hedycera Pascoe to the tribe Lechriopini. The most recent generic catalogue, proposed by Alonso-Zarazaga and Lyal (1999), generally adhered to Hustache’s treatment. The diagnostic characteristics of Mecopini remain controversial. Traditionally, the funicle with six antennomeres serve as the tribal diagnosis (Morimoto 1962; Anzaldo 2017; Legalov 2018). However, the exceptional cases occur in several genera. For instance, it has been reported that Emexaure Pascoe and Mecopoidellus Hustache exhibit seven funicular antennomeres (Pascoe 1871; Hustache 1931). This discordance raises doubts about the validity of the current classification of Mecopini. As mentioned above, this group has been understudied for a long time. Its unreliable tribal diagnosis suggests the uncertainty about its monophyly, which is a significant knowledge gap in the systematics of Conoderinae. Therefore, in this study, we revisited the morphological characters and applied four molecular markers to reconstruct the first phylogeny estimate of Mecopini, utilizing specimens from Taiwan and the Philippines. Our objectives are twofold: 1) to evaluate the validity of the current generic composition of Mecopini and propose a revised diagnosis of this tribe, and 2) to reassess the taxonomic status of mecopine genera from Taiwan and the Philippines. MATERIALS AND METHODS Morphological examination The specimens examined in this study were deposited in the following institutions: NHMUK: British Museum of Natural History, London, UK. MSNG: Museo Civico di Storia Naturale di Genova “Giacomo Doria”, Genova, Italy. NMNS: Natural Museum of Natural Sciences, Taichung, Taiwan. SDEI: Senckenberg Deutsches Entomologisches Institut, Müncheberg, Germany. SNSD: Senckenberg Naturhistorische Sammlungen Dresden, Germany. We obtained 20 dry specimens from Taiwan and the Philippines to infer the phylogenetic relationship within Mecopini, representing nine species of seven genera and one subgenus. We also included four conoderine species as outgroups, with an unidentified Bariditae species serving as the most distant outgroup. Closer outgroups included an unidentified Conoderitae species and two species of Coryssomerini (Metialma sp. and Phytophilus amoena (Pascoe, 1871)). The examined specimens were acquired from, or subsequently deposited in the NMNS. Specimens were identified to the generic level based on the keys of Pascoe (1871) and Heller (1894 1931) and to the species level based on the original descriptions and illustrations. The identifications of five species were further compared to the type specimens, including Talanthia phalangium Pascoe and Mecopus hopei Rosenschöld referred to the figures of Grebennikov and Zyskowski (2018) and Tseng and Cheng (2023), as well as Chirozetes (Chirozetes) arotes Heller, C. (Mesochirozetes) formosanus Heller and Pempheres habena Pascoe page 2 of 13Zoological Studies 63:49 (2024) © 2024 Academia Sinica, Taiwan from the photos of type specimens deposited in SNSD and NHMUK. To conduct a detailed morphological comparison between Pempheres and Mesochirozetes, we examined 19 additional specimens and acquired photos of type series from all described species of both taxa. These included P. habena, P. trilineata Pascoe, P. picta Heller and C. (Mesochirozetes) formosanus, deposited at NMNS, MSNG, SDEI, and SNSD. Label data of type specimens are cited verbatim, with a double slash (//) denoting data from different labels, a single one (/) those on different lines on a label and square brackets ([]) describing the color and status of the label. Examinations and dissections of the specimens were conducted using a Nikon SMZ 800N stereomicroscope. Muscles from mesoand metathorax were removed during dissection and preserved in 95% EtOH at -20℃ until DNA extraction. Photographs were captured using the same stereomicroscope with the SGviews software (Sage Vision CO., LTD, Taiwan), and a Nikon D610 equipped with a Nikon AF-S FX Micro 105 mm F2.8 G IF-ED VR lens. Image stacking was achieved using Helicon focus 7.5.1 (Helicon Soft Ltd., Ukraine). DNA extraction, sequencing and bioinformatics Genomic DNA was extracted from thoracic muscles using the QIAamp DNA Micro kit (Qiagen, Hilden, Germany). Our study employed four molecular markers: mitochondrial cytochrome c oxidase subunit I (COI), as well as three nuclear loci - 28S rRNA, Arginine Kinase (ArgK) and Elongation factor 1-α (EF1α). Polymerase chain reactions (PCR) were conducted for all four markers within a total reaction volume of 25.5 µL, comprising 3 µL of template DNA, 9 µL H2O, 0.5 µL of each 10 µM primer and 12.5 µL EmeraldAmp® MAX HS PCR Master Mix. Detailed primer information and PCR conditions are provided in table S1. PCR products were visualized by 1% agarose gel electrophoresis. Sequencing was performed using an ABI PRISM 3730 Genetic Analyser, facilitated by the National Yang Ming Chiao Tung University Cancer Progression Research Center (Taipei, Taiwan). Sequences were checked and edited by Geneious 11.0.5. (Kearse et al. 2012). The protein-coding genes were translated into amino acid to confirm any potential stop codons. We accessed sequences from GenBank for two mecopine species (Talanthia sp. and Mecopus bispinosus (Weber, 1801), with accession numbers provided in Table S2). Sequences alignments for each locus were conducted using MAFFT v.7. (Rozewicki et al. 2019), and subsequently concatenated using Mesquite v.3.6. (Maddison and Maddison 2022). Phylogenetic analyses Phylogenetic reconstruction employed both maximum likelihood (ML) and Bayesian inferences (BI) algorithms. ML analysis was conducted using RAxML v. 8.2.10. (Stamatakis 2014), utilizing the default GTR + G substitution model with sequences partitioned by locus. Node support values were obtained through rapid bootstrap analysis with 1000 iterations. Rapid bootstrap values greater than 75 but less than 90 were considered moderately supported, while those exceeding 90 were regarded as robustly supported. For BI analysis, the best substitution model for each locus was estimated using jModelTest2 (Darriba et al. 2012), which suggested GTR + I + G for COI, TVM + I + G for 28S rRNA, TIM2ef + G for ArgK, and TIM1 + I + G for EF1α. The BI analysis was performed using MrBayes v.3.1.2 (Ronquist et al. 2012) within the CIPRES science gateway (Miller et al. 2010), involving 10 million generations, a sampling frequency of 1,000 generations and a 25% burn-in. We considered posterior probabilities greater than 0.75 but less than 0.95 as moderately supported, and probabilities exceeding 0.95 as robustly supported. The topologies from ML and BI analyses were visualized using Interactive Tree Of Life (iTOL) v5 (Letunic and Bork 2021). RESULTS Morphological examination Nine mecopine species were recognized for phylogenetic reconstruction, including Agametis festiva Pascoe, 1870, Chirozetes (Chirozetes) arotes Heller, 1915, C. (Mesochirozetes) formosanus Heller, 1931, Pempheres habena Pascoe, 1871, Talanthia phalangium Pascoe, 1871, Mecopus bispinosus (Weber, 1801) and M. hopei Rosenschöld, 1838. Two specimens remain unidentified at the species level. One specimen is tentatively designated as Phylaitis cf. v-album Pascoe, 1871, based on its similarity of dorsal habitus, despite its geographical distance from the type locality. The other is an undescribed Pempherulus species. The sampling includes five speciose genera of Mecopini: Agametis (14 species), Chirozetes (2 subgenera and 20 species), Mecopus (48 species), Phylaitis (10 species), and Pempherulus (8 described species), as well as two genera with relatively fewer species: Pempheres (3 species) and Talanthia (4 species). Notably, A. festiva, T. phalangium, and M. bispinosus are the type species for their respective genera, and C. (M.) formosanus is the type species of the subgenus Mesochirozetes Heller, 1931. Detailed images of page 3 of 13Zoological Studies 63:49 (2024) © 2024 Academia Sinica, Taiwan the dorsal habitus of voucher specimens have been deposited in Zenodo (https://zenodo.org/doi/10.5281/ zenodo.8156265), and specimen details are provided in table S2. Morphological comparisons between the genus Pempheres and the subgenus Mesochirozetes reveal similarities between these two taxa. Males of three out of four described species, with the exception of P. picta (known only from a single female specimen), do not exhibit prosternal spines and hairs on the ventral side of protarsi, which are common in other mecopine genera. Sexual dimorphism is evident in the abdomens of Pempheres and Mesochirozetes. Males of P. trilineata and P. habena exhibit a pair of tubercles in the middle of ventrite I, which are somewhat denticulate and project inward on the posterior margin, forming a canaliculate structure. C. (M.) formosanus exhibits similar canaliculate structures, but differs in the morphology of tubercles that are not denticulate and have distinct hairs on the inner margin. Additionally, the canaliculate structures of Mesochirozetes can also be found on ventrite V. Detailed comparisons can be found in the following taxonomic section and discussion. Phylogenetic analyses The final concatenated matrix includes 24 individuals, comprising a total of 3658 bp. The specific number and length of all loci are as follows: 19 individuals for COI (ranging from 569 to 1219 bp), 21 for 28S rRNA (ranging from 451 to 677 bp), 17 for ArgK (ranging from 534 to 788 bp), and 18 for EF1α (ranging from 608 to 640 bp). No indels or stop codons were detected in the protein-coding loci (COI, ArgK and EF1α) (Fig. 1). All sequences have been deposited in GenBank, and the accession numbers are provided in Fig. 1. Phylogenetic tree based on four molecular markers. The node support is presented with bootstrap values (left) and posterior probability (right) under each branch. Mecopine species are highlighted, and the head morphologies of three species are illustrated on the right. page 4 of 13Zoological Studies 63:49 (2024) © 2024 Academia Sinica, Taiwan table S2. The ML and BI analyses consistently produce nearly identical topologies, with the only difference occurring in the relationship between Bariditae sp. and Agametis festiva (the BI topology is provided in Fig. S1). In both topologies, a polyphyletic Mecopini was recovered, with Agametis locating at a relatively early diverging position distantly separated from other mecopine genera. Conversely, seven other genera/ Subgenera collectively form a robustly supported clade, with bootstrap value at 100 and posterior probability at 1. Within this clade, Chirozetes arotes is the first derived lineage, followed by a monophyletic group comprising C. (M.) formosanus and Pempheres habena. The remaining four genera constitute a moderately supported clade, with Phylaitis forming a sister group of Talanthia, and Pempherulus aligning as a sister to Mecopus. It is important to highlight that two Chirozetes subgenera display a polyphyletic relationship. The nominal subgenus represents an independent lineage, and Mesochirozetes is positioned as a sister to Pempheres. TAXONOMY Tribe Mecopini Lacordaire, 1866 Diagnosis: Funicle with six antennomeres. We reidentify the absence of a prosternal canal as a diagnostic characteristic, as a consequence of excluding the genus Agametis from this tribe (see DISCUSSION). Genus Pempheres Pascoe, 1871 Type species: Pempheres trilineata Pascoe, 1871 (by present designation). Diagnosis (modified after Pascoe (1871) and Heller (1894)): Funicle with antennomere 2 twice longer than 1; male without prosternal spines (Fig. 3C, D) and hairs on the ventral of protarsi; abdominal ventrite I with medial canaliculate structures (Fig. 4C, D). We regard two diagnostic characters—the sinuated protibia and the proximity of antennal scape to rostral base— as invalid for distinguishing this genus from other mecopine genera (see details in the DISCUSSION). Remarks: The type species of this genus was not designated in the original description and remained so until now (Pascoe 1871; Alonso-Zarazaga and Lyal 1999). Among the two species described in the original description of Pempheres, we designate P. trilineata as the type species. The decision is based on the type series of P. trilineata containing both male and female specimens, in contrast to the type series of P. habena containing only females, which provide less morphological information. The presence of canaliculate structures on the abdomen of males suggests that Mecopus serrirostris Pascoe, 1871 and M. ceylanensis Heller, 1894 probably belong to this genus (Heller 1894). Pempheres trilineata Pascoe, 1871 (Figs. 2A; 3D; 4D) Diagnosis: Pronotum with lateral stripe straight, space between longitudinal stripes without spotted scales; elytra with distinct longitudinal lateral stripe, with lateral stripe continuous, medial stripe uniform in width along entire length; scales whitish. Types: Lectotype: 1 ♀, Type [red circular label, print] // Batchian [blue oval label, hand writing] // Pempheres / trilineata / Pasc [white rectangular label, hand writing] // Pascoe Coll. / 93–60 [white rectangular label, print] // NHMUK015009734 (NHMUK). Paralectotypes: 1 ♂, Morty [blue oval label, hand writing] // Pascoe Coll. / 93–60 [white rectangular label, print] // NHMUK015014006 (NHMUK); 1 ♂, Amboyna [blue oval label, hand writing] // Pempheres / trilineata Pasc [white rectangular label, hand writing] // Pascoe Coll. / 93–60 [white rectangular label, print] // NHMUK015014005 (NHMUK). Distribution: Maluku Islands, Indonesia (Pascoe 1871). Remark: Pascoe (1871) did not explicitly designate a primary type in the original description, resulting in all specimens used for the description being considered syntypes with equal nomenclatural status. The exact number of specimens used for the species description was not specified, but he mentioned that the specimens were collected from three localities: “Hab. Batchian, Morty, Amboyna.” There are three such specimens in his collection at NHMUK, recognized as the syntypes. To establish a definitive, name-bearing type for P. trilineata, we designate the female syntype from Batchian (labeled “type”), which closely matches Pascoe’s description, as the lectotype of P. trilineata. The other two male specimens from the type series are designated as paralectotypes. Pempheres habena Pascoe, 1871 (Figs. 2B; 3C; 4C) Mecopus abdominalis Kirsch, 1875 (synonymized by Heller 1894: 12). Diagnosis: Pronotum with lateral stripe straight, space between longitudinal stripes without spotted scales; elytra with distinct longitudinal lateral stripe, with lateral stripe interrupted on basal half, medial page 5 of 13Zoological Studies 63:49 (2024) © 2024 Academia Sinica, Taiwan Fig. 2. Type specimens of Pempheres and Mesochirozetes in dorsal view. A, lectotype of Pempheres trilineata Pascoe, 1871; B, lectotype of Pempheres habena Pascoe, 1871; C, holotype of Pempheres picta Heller, 1894; D, lectotype of Chirozetes (Mesochirozetes) formosanus Heller, 1931. Photo credits: A–B, Keita Matsumoto (NHMUK); C, Roberto Poggi (MSNG). page 6 of 13Zoological Studies 63:49 (2024) © 2024 Academia Sinica, Taiwan stripe widest anteriorly, narrowed posteriorly; scales yellowish. Types: Lectotype: 1 ♀, Type [red circular label, print] // Singapore [blue oval label, hand writing] // Pempheres / habena / Pasc [white rectangular label, hand writing] // Pascoe Coll. / 93–60 [white rectangular label, print] // NHMUK015009754 (NHMUK). Paralectotype: 1 ♀, Sumatra [blue oval label, hand writing] // Pempheres / habena Pasc [white rectangular label, hand writing] // Pascoe Coll. / 93–60 [white rectangular label, print] // NHMUK015009755 (NHMUK). Other material: MALAYSIA: 1 ♂, Malacca [yellow rectangular label, hand writing] // Typus [pink rectangular label, print] // 1023 [yellow rectangular label, hand writing] // Mecopus abdomina- / lis Kirsch = Pempheres / habena Pascoe [white rectangular label, print] // Staatl. Museum für / Tierkunde, Dresden [white rectangular label, print] (SNSD); 1 ex., Perak / Malacca / (Doherty) [rectangular label, print] // 119. [rectangular label, hand writing] // Pempheres / habena / Pascoe / det. Heller 1893-1912 [rectangular label, hand writing] // MUSEO GENOVA / coll. Angelo Solari / (acquisto 2000) [white rectangular label, print] (MSNG); 1 ♀, PERAK, F. M. S. / Batang Padang / Jor Camp 1500 ft. / May 29 1923 / H.M. Pendlebury leg. [rectangular label, print and hand write] // Pempheres / habena Pasc. / det. G.A.K. Marshall [rectangular label, print and hand write] // Ex F.M.S. / Museum / B.M. 1955354. [rectangular label, print] // NHMUK015014004 (NHMUK); 1 ♂, MALAY PENINS / Endong Roose / Pelialing gajal / 20.6.1928 [rectangular label, print and hand write] // PEMPHERES / HABENA, Pasc. [rectangular label, hand write] // 589 [rectangular Fig. 3. Comparison of male prosternum of Chirozetes, Mesochirozetes and Pempheres spp. Males of Chirozetes exhibit distinct prosternal spines, where Mesochirozetes and Pempheres do not. A, Chirozetes arotes Heller, 1915; B, Mesochirozetes formosanus (Heller, 1931); C, Pempheres habena Pascoe, 1871; D, Pempheres trilineata Pascoe, 1871. Photo credits: D, Keita Matsumoto (NHMUK). page 7 of 13Zoological Studies 63:49 (2024) © 2024 Academia Sinica, Taiwan label, hand write] // Ex F.M.S. / Museum / B.M. 1955354. [rectangular label, print] // NHMUK015014003 (NHMUK). PHILIPPINES: 1 ♂, Kasibu, Nueva Viscaya, North Luzon, V.2020, local collector leg. // WZPCC_03596 (NMNS); 1 ♀, Roxas, Palawan, II.2021, local collector leg. // WZPCC_03597 (NMNS). Distribution: Singapore; Sumatra Island, Indonesia; Peninsular Malaysia; Philippines (Pascoe 1871; Heller 1894; Schultze 1916). Remark: Pascoe (1871) did not explicitly designate a primary type in the original description, resulting in all specimens used for the description being syntypes with equal nomenclatural status. The exact number of specimens used for the species description was also not specified, but he mentioned that the specimens were collected from two localities: “Hab. Singapore, Sumatra.” There are two such specimens in his collection at NHMUK, recognized as the syntypes. To establish a definitive, name-bearing type for P. habena, we designate the female syntype from Singapore (labeled “type”), which closely matches the original description, as the lectotype of P. habena. The other female specimen from the type series is designated as a paralectotype. Pempheres picta Heller, 1894 (Fig. 2C) Diagnosis: Pronotum with lateral stripe sinuate, space between longitudinal stripes with spotted scales; elytra without or only with indistinct longitudinal lateral stripe, apical half densely covered with spotted, patchy scales; metepisternum covered with a patch of black scales. Fig. 4. Comparison of male abdomens of Chirozetes, Mesochirozetes and Pempheres spp. Males of Mesochirozetes and Pempheres exhibit distinct canaliculate structures, where Pempheres occurs on ventrite I, while Mesochirozetes on ventrite I and V. A, Chirozetes arotes Heller, 1915; B, Mesochirozetes formosanus (Heller, 1931); C, Pempheres habena Pascoe, 1871; D, Pempheres trilineata Pascoe, 1871. Photo credits: D, Keita Matsumoto (NHMUK). page 8 of 13Zoological Studies 63:49 (2024) © 2024 Academia Sinica, Taiwan Types: Holotype: 1 ♀, Tenasserim / Thagatà / Fea. Apr. 1887 [rectangular label, print] // Typus [red rectangular label, hand writing] // Pempheres (?) pictus Heller / Determ: K.M. Heller. ♀ [rectangular label, print and hand writing] // picta / Heller [rectangular label, hand writing] // Pempheres / picta, Heller / typus! [yellow rectangular label, hand writing] // Museo Civico / di Genova [white rectangular label, print] (MSNG). Other material: LAOS: 1ex., Laos / Kiong Kouang / Vitalis 1919 [rectangular label, hand writing] // picta / Hllr. / det. Solari, 920 [rectangular label, hand writing] // MUSEO GENOVA / coll. Angelo Solari / (acquisto 2000) [white rectangular label, print] (MSNG). Distribution: Tenasserim, Myanmar (Heller 1894); Laos (new distribution record). Remarks: Heller (1894) did not designate a primary type in the original description. However, the species description appears to be based on a single specimen, for which he provided only one measurement and explicitly stated the label details as “Patria: Tenasserim, Thagala, legit Fea, April 1887, Mus. Civico Genua”. There is indeed only one such specimen in his collection at MSNG, which is labeled as “Typus” and recognized as the holotype in this study. Heller (1894) mentioned the uncertainty regarding the generic placement of this species, as indicated by a question mark in the original description and on the holotype label. Our examinations reveal the morphological similarities between P. picta and Mesochirozetes formosanus, such as sinuated lateral stripes on the pronotum and spotted scale patches on the elytra, suggesting a close relationship between these species. Additional specimens and further morphological and molecular examinations are necessary for verifying the taxonomic status of this species. Genus Mesochirozetes Heller, 1931 stat. nov. Type species: Chirozetes (Mesochirozetes) formosanus Heller, 1931 (by monotypy). Diagnosis (modified after Heller (1931)): Funicle with antennomere 2 as long as, or slightly longer than 1; male without prosternal spines (Fig. 3B) and hairs on the ventral of protarsi; abdominal ventrite I and V with medial canaliculate structures (Fig. 4B). Mesochirozetes formosanus (Heller, 1931) comb. nov. (Figs. 2D; 3B; 4B) Chirozetes (Mesochirozetes) formosanus Heller, 1931. Diagnosis: Pronotum with lateral stripe sinuate, space between longitudinal stripes with spotted scales; elytra without or only with indistinct longitudinal stripe, apical half densely covered with spotted, patchy scales; integument reddish brown; metepisternum covered with white scales. Types: Lectotype: TAIWAN: 1 ♂, Formosa / Kosempo / H. Sauter’09 [yellow rectangular label, print and hand writing] // 1909 / 22 [white rectangular label, print and hand writing] // Typus! [red rectangular label, print] // ♂ [white rectangular label, hand writing] // Staatl. Museum für / Tierkunde, Dresden [white rectangular label, print] (SNSD). Paralectotypes: 1 ♂, Formosa / Kosempo / H. Sauter’09 [yellow rectangular label, print and hand writing] // 1909 / 22 [white rectangular label, print and hand writing] // Paratypus / formosanus Hell. [red rectangular label, print and hand writing] // ♂ [white rectangular label, hand writing] // Staatl. Museum für / Tierkunde, Dresden [white rectangular label, print] (SNSD); 1 ♂, 1909 / 22 [white rectangular label, print and hand writing] // Formosa / Kosempo / H. Sauter’09 [yellow rectangular label, print and hand writing] // ♂ Paratypus / formosanus Hell. [red rectangular label, print and hand writing] // Staatl. Museum für / Tierkunde, Dresden [white rectangular label, print] (SNSD); 1 ♀, 1909 / 22 [white rectangular label, print and hand writing] // Formosa / Kosempo / H. Sauter’09 [yellow rectangular label, print and hand writing] // ♀ Typus / formosanus Hell. [red rectangular label, print and hand writing] // ♀ [white rectangular label, hand writing] // Staatl. Museum für / Tierkunde, Dresden [white rectangular label, print] (SNSD); 1 ♂, Formosa / Kosempo / H. Sauter’09 [yellow rectangular label, print and hand writing] // 1909 / 22 [white rectangular label, print and hand writing] // Syntypus [red rectangular label, print] // Cotypus / P. formosana / Heller [red rectangular label, print and hand writing] // Pempheres / formosana m / Det. K.M. Heller 1913 [rectangular label, print and hand writing] // SDEI Coleoptera / # 304541 (SDEI); 1 ♂, XI Formosa / Kosempo / H. Sauter 1908 [white rectangular label, print and handwriting] // g.n. / Mesochirozetes [white rectangular label, handwriting] // (Pempheres) Mesochirozetes / formosana n.sp. / Det. K.M. Heller 1920 [white rectangular label, print and handwriting] // SDEI Coleoptera / # 304543 (SDEI); 1 ex., Formosa / Kosempo / Sauter_VIII_.07-09 [white rectangular label, print and handwriting] // SDEI Coleoptera / # 304544 (SDEI); 1 ex., XI Formosa / Kosempo / H. Sauter 1908 [white rectangular label, print and handwriting] // SDEI Coleoptera / # 304546 (SDEI); 1 ♀, Kosempo (Formosa) / H. Sauter VI 1929 [white rectangular label, print and handwriting] // SDEI Coleoptera / # 304547 (SDEI). Other materials: TAIWAN: 1 ♂, Formosa / Hoozan / H. Sauter 1910 [yellow rectangular label, page 9 of 13Zoological Studies 63:49 (2024)