71 research outputs found
Genome of the Asian Longhorned Beetle (\u3cem\u3eAnoplophora glabripennis\u3c/em\u3e), a Globally Significant Invasive Species, Reveals Key Functional and Evolutionary Innovations at the Beetle-Plant Interface
Background: Relatively little is known about the genomic basis and evolution of wood-feeding in beetles. We undertook genome sequencing and annotation, gene expression assays, studies of plant cell wall degrading enzymes, and other functional and comparative studies of the Asian longhorned beetle, Anoplophora glabripennis, a globally significant invasive species capable of inflicting severe feeding damage on many important tree species. Complementary studies of genes encoding enzymes involved in digestion of woody plant tissues or detoxification of plant allelochemicals were undertaken with the genomes of 14 additional insects, including the newly sequenced emerald ash borer and bull-headed dung beetle. Results: The Asian longhorned beetle genome encodes a uniquely diverse arsenal of enzymes that can degrade the main polysaccharide networks in plant cell walls, detoxify plant allelochemicals, and otherwise facilitate feeding on woody plants. It has the metabolic plasticity needed to feed on diverse plant species, contributing to its highly invasive nature. Large expansions of chemosensory genes involved in the reception of pheromones and plant kairomones are consistent with the complexity of chemical cues it uses to find host plants and mates. Conclusions: Amplification and functional divergence of genes associated with specialized feeding on plants, including genes originally obtained via horizontal gene transfer from fungi and bacteria, contributed to the addition, expansion, and enhancement of the metabolic repertoire of the Asian longhorned beetle, certain other phytophagous beetles, and to a lesser degree, other phytophagous insects. Our results thus begin to establish a genomic basis for the evolutionary success of beetles on plants
Genome of the Asian longhorned beetle (Anoplophora glabripennis), a globally significant invasive species, reveals key functional and evolutionary innovations at the beetleâplant interface
Background
Relatively little is known about the genomic basis and evolution of wood-feeding in beetles. We undertook genome sequencing and annotation, gene expression assays, studies of plant cell wall degrading enzymes, and other functional and comparative studies of the Asian longhorned beetle, Anoplophora glabripennis, a globally significant invasive species capable of inflicting severe feeding damage on many important tree species. Complementary studies of genes encoding enzymes involved in digestion of woody plant tissues or detoxification of plant allelochemicals were undertaken with the genomes of 14 additional insects, including the newly sequenced emerald ash borer and bull-headed dung beetle.
Results
The Asian longhorned beetle genome encodes a uniquely diverse arsenal of enzymes that can degrade the main polysaccharide networks in plant cell walls, detoxify plant allelochemicals, and otherwise facilitate feeding on woody plants. It has the metabolic plasticity needed to feed on diverse plant species, contributing to its highly invasive nature. Large expansions of chemosensory genes involved in the reception of pheromones and plant kairomones are consistent with the complexity of chemical cues it uses to find host plants and mates.
Conclusions
Amplification and functional divergence of genes associated with specialized feeding on plants, including genes originally obtained via horizontal gene transfer from fungi and bacteria, contributed to the addition, expansion, and enhancement of the metabolic repertoire of the Asian longhorned beetle, certain other phytophagous beetles, and to a lesser degree, other phytophagous insects. Our results thus begin to establish a genomic basis for the evolutionary success of beetles on plants
Chaoborus flavicans
<p> <b> Species list of <i>C</i>. <i>flavicans</i> complex</b> </p> <p> <i>Chaoborus flavicans</i> (Meigen, 1830). Type locality: Germany (Giles 1902, Borkent 2014)</p> <p> <i>Chaoborus albipes</i> (Johannsen, 1903). Type locality: Ithaca, New York, USA (Borkent 2014).</p> <p> <i>Chaoborus posio</i> Salmela, 2021. Type locality: Posio, Lapland, Finland (Salmela <i>et al</i>. 2021b)</p> <p> <i>Chaoborus pseudoflavicans</i> <b>sp. nov.</b> Type locality: Haenam-gun, Jeollanam-do, Korea</p> <p> <b>Diagnosis. Adult male.</b> See Salmela <i>et al</i>. (2021b) for morphological details. Flagellomeres annulated circularform with partly darked or pale whorl bases. Scutellar stripes light brown to almost black with pale lateral stripes. Legs mostly light brown with darkened apical tarsomeres. Paramere of male hypopygium elongated, conspicuous apical claw, slightly curved or straight.</p> <p> <b>Pupa.</b> Mid rib of terminal process slightly darkened than lateral ribs, outer rib of terminal process smooth with no spines.</p> <p> <b>IV instar larva.</b> Mandibular tooth 3 (subordinate tooth) placed in at the middle of tooth 2 and tooth 4. Lateral teeth inconspicuous (shorter than first lateral tooth) or conspicuous (long as first lateral tooth) and elongated labral blades.</p>Published as part of <i>Bang, Woo Jun & Shin, Seunggwan, 2023, A new species of the Chaoborus flavicans complex (Diptera, Chaoboridae) in South Korea, pp. 57-81 in Zootaxa 5360 (1)</i> on page 59, DOI: 10.11646/zootaxa.5360.1.3, <a href="http://zenodo.org/record/10084843">http://zenodo.org/record/10084843</a>
Chaoborus pseudoflavicans Bang & Shin 2023, sp. nov.
<i>Chaoborus pseudoflavicans</i> sp. nov. <p> <i>Chaoborus crystallinus</i> (nec De Geer): Komyo 1954: 12.</p> <p> <i>Chaoborus</i> cf. <i>flavicans</i> (nec Meigen): Dupuis <i>et al</i>. 2008: 240.</p> <p> <i>Chaoborus flavicans</i> (nec Meigen): An <i>et al</i>. 2012: 39.</p> <p> <i>Chaoborus</i> sp. (unidentified): Zhang <i>et al</i>. 2019: 747.</p> <p> <i>Chaoborus</i> JPN sp. (unidentified): Salmela <i>et al</i>. 2021b: 181.</p> Differential diagnosis. <p> <b>Adult male.</b> See Samela <i>et al</i>. (2021b) to see the illustrations of <i>C</i>. <i>flavicans</i> species complex. This species can be distinguished from <i>C</i>. <i>posio</i> by its yellowish coloration (dark-almost in <i>C</i>. <i>posio</i>), and from <i>C</i>. <i>flavicans</i> and <i>C</i>. <i>albipes</i> by the following combination of characters: Tergal bands absent (present in <i>C</i>. <i>flavicans</i> and <i>C</i>. <i>albipes</i>). Paramere unicolorous, constricted and medially bent, apical claw stout and curved (bicolorous, constricted and medially bent, apical claw narrow and slightly curved in <i>C</i>. <i>flavicans</i> and nearly unicolorous, slightly bent or straight, apical claw stout and curved in <i>C</i>. <i>albipes</i>).</p> <p> <b>Pupa.</b> This species may be hardly distinguished due to intraspecific variation in respiratory organ morphology according to its aquatic habitats (pond and lake). Respiratory organs subapically constricted (absent in <i>C</i>. <i>posio</i>). Length of respiratory horn mostly> 1000 μm and slender form (mostly <1000 μm in <i>C</i>. <i>albipes</i> and <i>C</i>. <i>posio</i>, medially wide in <i>C</i>. <i>posio</i>).</p> <p> <b>IV instar larva.</b> Mandibular lateral teeth conspicuous, first lateral tooth about as long as mandibular tooth III (short or inconspicuous in <i>C</i>. <i>flavicans</i>), number of lateral teeth almost <4 (almost> 5 in <i>C</i>. <i>albipes</i> and <i>C</i>. <i>posio</i>), number of mandibular fan bristles usually 10 (number> 20 in <i>C</i>. <i>albipes</i> and <i>C</i>. <i>posio</i>).</p> <p> <b>Type materials.</b> <b>Holotype.</b> Male (SNUE), 01.II.2023, Haenam-gun, Jeollanam-do, South Korea, 34°28'06.30"N, 126°31'02.31"E, Woo Jun Bang and Jeungjun Lee. <b>Paratypes.</b> 20 adult males and 20 adult females, 100 larvae and 100 pupae (SNUE); 6 adult males, 6 adult females, and 10 larvae and 10 pupae are deposited at the Regional museum of Lapland, Rovaniemi, Finland (LMM). all materials from same collection data as holotype. 10 adult males and 10 adult females, pinned. 10 adult males and 10 adult females in 70 % EtOH. All larval and pupal specimens preserved in 70 % EtOH. Three male hypopygia on slides.</p> Description <p> <b>Adult male. Head.</b> Dark brown with pale setae; Antennae 14-segmented, bearing whorl pale setae; antennal flagellomeres circular form, basal segments dark brown, but distal segments pale; apical flagellomere dark brown, length of penultimate flagellomere 295 (268–320), apical flagellomere 224 (183–262), penultimate/apical 1.32 (1.03– 1.74, n=7); maxillary palpi 5-segmented, all segments greyish brown with dark brown setae. Length of palpomeres 1–4 (n=5): 1st 76 (69–80), 2nd 110 (99–120), 3rd 249 (204–289), 4th 231 (192–256) (Fig. 2a–b). <b>Thorax.</b> Scutum with trident light brown stripes and some black specks scattered, ground color brown with pale setae; scutellum and mediotergite brown, most pleuron colors composed pale to brown areas: antepronotum, postpronotum, anepimeron, anepisternum, metanepsiternum and katepisternum brown (antepronotum slightly darkened than postpronotum), halteres pale, a number of thorax setae (n=12): antepronotum 26 (22–29), postpronotum 5 (3–6), proepisternum 5 (4–6), katepisternum 7 (4–9), anepisternum 11 (8–12) and anepimeron 5 (5–9) (Fig. 2a). <b>Leg.</b> Mostly pale, but fourth-fifth tarsomeres slightly darkened than first to third tarsomeres; foreleg, lengths of femur, tibia and five tarsomeres (n=12): femur 2069 (1992–2226), tibia 2259 (2123–2357), tarsomeres: 1st 931 (861–992), 2nd 567 (510–628), 3rd 483 (440–544), 4th 321 (273–385), 5th 218 (161–248); midleg, lengths of femur, tibia and five tarsomeres (n=12): femur 1714 (1648–1775), tibia 1716 (1649–1815), tarsomeres: 1st 735 (701–792), 2nd 443 (415–471), 3rd 355 (334–390), 4th 269 (251–298), 5th 235 (220–242); hindleg, lengths of femur, tibia and five tarsomeres (n=12): femur 2189 (1970–2400), tibia 2170 (1806–2373), tarsomeres: 1st 1250 (1197–1291), 2nd 730 (686–756), 3rd 494 (472–524), 4th 308 (295–330), 5th 260 (235–288) (Fig. 2a). <b>Wing.</b> mostly light brown with yellowish scales around the margin, length 4238 (4102–4334), width 881 (867–906), length/width 4.8 (4.9–4.5), fork of R 2+3 517 (395–654), fork of M 1+2 461 (400–490), R 3 1288 (1120–1385), M 1 1136 (1059–1184) (n=10) (Fig. 2b). <b>Abdomen.</b> Ground color light brown with black lateral specks but not connected, tergal bands absent, fifth to distal tergal segments slightly darkened (Fig. 2b). <b>Hypopygium.</b> Gonocoxite light brown, length 538 (512–547), width 186 (167–206), length/width 2.9 (2.5–3.3, n=7); gonostylus mostly dark brown, length 485 (449–518), width 36 (32–39), length/width 16.19–11.51 (n=7) (Fig. 3a); paramere unicolorous, brown, medially bent and constricted, apical claw stout and curved, length 149 (133–160, n=5) (Fig. 3b–c).</p> <p> <b>Adult female.</b> Most are similar with male. <b>Head.</b> Length of penultimate flagellomere 95 (84–115), apical flagellomere 104 (94–134). penultimate/apical 0.92 (0.63–1.30, n=4); maxillary palpi 5-segmented, dark brown, length of palpomeres 1–4 (n=6): 1st 55 (51–63), 2nd 65 (58–69), 3rd 174 (149–209), 4th 149 (131–167). <b>Thorax.</b> Number of setae on thorax (n=8): antepronotum 20 (17–22), postpronotum 5 (5–6), proepisternum 4 (3–5), katepisternum 5 (3–6), anepisternum 11 (10–13), anepimerum 11 (6–11). <b>Leg.</b> Foreleg, lengths of femur, tibia and five tarsomeres (n=6): femur 1591 (1543–1663), tibia 1846 (1776–1902), tarsomeres: 1st 800 (736–874), 2nd 484 (437–511), 3rd 385 (337–423), 4th 255 (227–282), 5th 180 (162–209); midleg, lengths of femur, tibia and five tarsomeres (n=4): femur 1506 (1442–1596), tibia 1456 (1420–1495), tarsomeres: 1st 631 (600–652), 2nd 354 (322– 394), 3rd 286 (281–296), 4th 199 (182–213), 5th 168 (153–180); hindleg, lengths of femur, tibia and five tarsomeres (n=5): femur 1814 (1725–1861), tibia 1836 (1773–1916), tarsomeres: 1st 1098 (1030–1166), 2nd 609 (562–644), 3rd 400 (349–445), 4th 236 (212–263), 5th 175 (161–194). <b>Wing</b>. length 3441 (3383–3517), width 945 (879–991), length/width 3.6 (3.4–4.0), fork of R 2+3 358 (290–406), fork of M 1+2 303 (273–320), R 3 1207 (934–1296), M 1 1105 (832–1254) (n=6).</p> <p> <b>Pupa</b> (Fig. 4b). Mib rib of terminal process incomplete, not reaching the distal margin of paddles, and curved apically; outer rib of terminal process curved shape and smooth with no spines; mid rib and lateral rib almost pale, but mid rib slightly darkened than lateral rib; respiratory organ, slender form, subapically constricted, length 1141 (1016–1187), width 225 (205–309), length/width 4.6 (3.3–5.9, n=10) (Fig. 4e)</p> <p> <b>IV instar larvae</b> (Fig. 4a). Length of antennae 476 (401–530, n=19); labral blade transparent and serrated, length 229 (201–279), width 48 (31–58), length/width 4.8 (3.5–9.0, n=14) (Fig. 4d); a number of mandibular fan bristles 10.8 (10–13, n=19); mandibular teeth, mandibular tooth 1,2 and 4 darkened apically, mandibular tooth 3 dark; lateral teeth conspicuous, first lateral tooth about as long as mandibular tooth 3 (subordinate tooth), average number of lateral teeth 3.4 (3–4, n=21) (Fig. 4c); a number of anal fan setae 23 (21–26, n=15).</p> <p> <b>Etymology.</b> The name of this species reflects its taxonomic history, as it was often identified as <i>C</i>. <i>flavicans</i> and remained undescribed for a prolonged period within the <i>C</i>. <i>flavicans</i> species complex.</p> <p> <b>DNA barcodes & neighbor-joining tree.</b> Partial COI sequences from larvae to adults were obtained. Based on the pairwise distance histogram, the intraspecific variation within the species complex ranged up to 4.9% (with a mode of 1.3%), while the minimum interspecific variation was 11.1% (with a mode of 15.4%). These results suggest that the genetic distances in the <i>C</i>. <i>flavicans</i> species complex are sufficient to delimitate and identify species (Fig. 5). In addition, it showed that the collected chaoborids are identical to <i>Chaoborus</i> JPN sp. sequenced in Zhang <i>et al</i>. (2019), and supported by the NJ tree, which clustered these sequences into a single group (> 99% support), similar to the COI-based tree of Salmela <i>et al</i>. (2021b). In the tree, C. <i>pseudoflavicans</i> <b>sp</b>. <b>nov</b>. formed a single cluster (Fig. 6). All results confirmed that C. <i>pseudoflavicans</i> <b>sp</b>. <b>nov</b>. is a new distinct species that has not yet been identified.</p> <p> <b>Distribution.</b> Korea (new record) and Japan.</p> <p> <b>Remarks.</b> The new species has been mentioned in some taxonomic works (e.g. Komyo 1954, Salmela <i>et al</i>. 2021b), and included in the molecular phylogeny of Zhang <i>et al</i>. (2019). While it was previously believed that this taxon was endemic to Japan (Salmela <i>et al</i>. 2021b), the morphological and molecular analyses showed that this species also occurs in the Korean Peninsula. In conclusion, the paramere of <i>C</i>. <i>pseudoflavicans</i> <b>sp</b>. <b>nov</b>. was practically identical to that of <i>C</i>. <i>albipes</i>, except for slightly greater curvature in the median position of the paramere. Additionally, the presence or absence of the tergal band in adults, the differences in mandibular teeth of larvae, and the DNA barcode confirmed it is a distinct species in the species complex.</p> <p> <b>Bionomics.</b> The immature specimens of this new species were collected from a small, lightly iced, fishless pond (10 × 10 m) in February and March 2023. The water was eutrophic, and colored light brown with <i>Typha</i> spp., and fallen leaves. Chironomid larvae and <i>Notonecta</i> spp. were also collected with the chaoborid larvae.</p>Published as part of <i>Bang, Woo Jun & Shin, Seunggwan, 2023, A new species of the Chaoborus flavicans complex (Diptera, Chaoboridae) in South Korea, pp. 57-81 in Zootaxa 5360 (1)</i> on pages 59-63, DOI: 10.11646/zootaxa.5360.1.3, <a href="http://zenodo.org/record/10084843">http://zenodo.org/record/10084843</a>
First record of Cordilura shatalkini Ozerov, 1997 and Cordilura nubecula Sasakawa, 1986 (Diptera: Scathophagidae) from Korea
The species of the genus Cordilura Fallén are not well studied in Korea with only one known species. In this study, Cordilura shatalkini and Cordilura nubecula are reported for the first time in Korea with a new key to the species of Cordilura from Korea
Chaoborus flavicans
Key to species of <i>Chaoborus flavicans</i> complex (based on Salmela <i>et al</i>. 2021b) Adult male <p> 1. Gonostylus rather short, length/width 9.43 (7.9–10.7); paramere dark, apical claw relatively long......... <i>C</i>. <i>posio</i> Salmela</p> <p>- Gonostylus rather narrow and long, length/width 12.6–13.7 (10.2–16.2); paramere light brown to brown, unicolorous or bicolorous, apical claw relatively short (Fig. 3a)............................................................. 2</p> <p> 2. Paramere bicolorous, apical claw relatively narrow and gently curved or straight................... <i>C</i>. <i>flavicans</i> (Meigen)</p> <p>- Paramere unicolorous, apical claw relatively stout and curved.................................................. 3</p> <p> 3. Paramere medially bent and constricted (Fig. 3b–c).......................... <i>C</i>. <i>pseudoflavicans</i> <b>sp. nov.</b> Bang & Shin</p> <p> - Paramere almost straight or slightly curved........................................... <i>C</i>. <i>albipes</i> (Johannsen, 1903)</p> Pupae <p>* Pond-dwelling specimens are hard to distinguish due to intraspecific variation.</p> <p> 1. Respiratory organ club-shaped, subapical constriction absent, relatively short 844 (770–930)............ <i>C</i>. <i>posio</i> Salmela</p> <p>- Respiratory organ slender or voluminous form, subapical constriction present..................................... 2</p> <p> 2. Length of respiratory organ> 1000 μm (920–1360), slender form in ponds (Fig. 4e); voluminous form in lakes............................................ <i>C</i>. <i>flavicans</i> (Meigen) / <i>C</i>. <i>pseudoflavicans</i> <b>sp. nov.</b> Bang & Shin (only slender form)</p> <p> - Length of respiratory organ mostly <1000 (690–1050), slender form...................... <i>C</i>. <i>albipes</i> (Johannsen, 1903)</p> IV instar larvae <p>* Serration of labral blades are mostly varied in all complex species.</p> <p> 1. Mandibular lateral teeth inconspicuous, first lateral tooth shorter or smaller than mandibular tooth 3 (subordinate tooth)........................................................................................ <i>C</i>. <i>flavicans</i> (Meigen)</p> <p>- Mandibular lateral teeth conspicuous, first lateral tooth about as long as mandibular tooth 3 (subordinate tooth)........... 2</p> <p> 2. Number of mandibular fan bristles <14 (usually 10–13), average number of lateral teeth almost <4 (3–4) (Fig. 4c)........................................................................... <i>C</i>. <i>pseudoflavicans</i> <b>sp. nov.</b> Bang & Shin</p> <p>- Number of mandibular fan bristles> 20, average number of lateral teeth> 5 (5–8).................................. 3</p> <p> 3. Number of mandibular fan bristles usually> 22, (up to 29); labral blade almost serrated, rather wide–length/width 3.7 (3–5)....................................................................................... <i>C</i>. <i>posio</i> Salmela</p> <p> - Number of mandibular fan bristles usually 15–21, (up to 25); labral blade almost smooth, rather narrow–length/width 5.6 (4.4–6.9)...................................................................... <i>C</i>. <i>albipes</i> (Johannsen, 1903)</p>Published as part of <i>Bang, Woo Jun & Shin, Seunggwan, 2023, A new species of the Chaoborus flavicans complex (Diptera, Chaoboridae) in South Korea, pp. 57-81 in Zootaxa 5360 (1)</i> on pages 63-65, DOI: 10.11646/zootaxa.5360.1.3, <a href="http://zenodo.org/record/10084843">http://zenodo.org/record/10084843</a>
Larvae of longhorned beetles (Coleoptera; Cerambycidae) have evolved a diverse and phylogenetically conserved array of plant cell wall degrading enzymes
Longhorned beetles (Cerambycidae) are the most diverse group of predominantly wood-feeding (xylophagous) insects on Earth. Larvae of most species feed within tissues of plants made up of large amounts of plant cell wall (PCW), which is notoriously difficult to digest. To efficiently access nutrients from their food source, cerambycid larvae have to deconstruct PCW polysaccharides â such as cellulose, hemicelluloses and pectin â requiring them to possess a diversity of plant cell wall degrading enzymes (PCWDEs) in their digestive tract. Genomic data for Cerambycidae are mostly limited to notorious forest pests and are lacking for most of the taxonomic groups. Consequently, our understanding of the distribution and evolution of cerambycid PCWDEs is quite limited. We addressed the numbers, kinds and evolution of cerambycid PCWDEs by surveying larval midgut transcriptomes from 23 species representing six of the eight recognized subfamilies of Cerambycidae and each with very diverse host types (i.e., gymnosperms, angiosperms, xylem, phloem, fresh or dead plant tissues). Using these data, we identified 340 new putative PCWDEs belonging to ten carbohydrate active enzyme families, including two gene families (GH7 and GH53) not previously reported from insects. The remarkably wide range of PCWDEs expressed by Cerambycidae should allow them to break down most PCW polysaccharides. Moreover, the observed distribution of PCWDEs encoded in cerambycid genomes agreed more with phylogenetic relationship of the species studied than with the taxonomic origin or quality of the host plant tissues
Phylogenomic analysis sheds light on the evolutionary pathways towards acoustic communication in Orthoptera
Acoustic communication is enabled by the evolution of specialised hearing and sound producing organs. In this study, we performed a large-scale macroevolutionary study to understand how both hearing and sound production evolved and affected diversification in the insect order Orthoptera, which includes many familiar singing insects, such as crickets, katydids, and grasshoppers. Using phylogenomic data, we firmly establish phylogenetic relationships among the major lineages and divergence time estimates within Orthoptera, as well as the lineage-specific and dynamic patterns of evolution for hearing and sound producing organs. In the suborder Ensifera, we infer that forewing-based stridulation and tibial tympanal ears co-evolved, but in the suborder Caelifera, abdominal tympanal ears first evolved in a non-sexual context, and later co-opted for sexual signalling when sound producing organs evolved. However, we find little evidence that the evolution of hearing and sound producing organs increased diversification rates in those lineages with known acoustic communication
Author Correction: Phylogenomic analysis sheds light on the evolutionary pathways towards acoustic communication in Orthoptera (Nature Communications, (2020), 11, 1, (4939), 10.1038/s41467-020-18739-4)
The original version of this Article contained an error in Fig. 3, in which the types of tegmino-tegminal stridulation in Gryllidea and in Tettigonioidea shown on the right side of the phylogeny were reversed. The correct version of Fig. 3 is:(figure presented)which replaces the previous incorrect version.(figure presented)The original version of this Article contained an error in the last sentence of the Fig. 3 legend, which incorrectly read âThe common ancestor of Gryllidea evolved âleft-over-rightâ stridulation, the common ancestor of Hagloidea evolved âambidextrousâ stridulation, and the common ancestor of Tettigonioidea evolved âright-over-leftâ stridulationâ. The correct version replaces this sentence with âThe common ancestor of Gryllidea evolved âright-over-leftâ stridulation, the common ancestor of Hagloidea evolved âambidextrousâ stridulation, and the common ancestor of Tettigonioidea evolved âleft-over-rightâ stridulationâ. The original version of this Article contained an error in the Discussion, which incorrectly read âCrickets and mole crickets stridulate by moving the left forewing over the right, and katydids stridulate in the opposite way by moving the right forewing over the left43â. The correct version replaces this sentence with âCrickets and mole crickets stridulate by moving the right forewing over the left, and katydids stridulate in the opposite way by moving the left forewing over the right43â. This has been corrected in both the PDF and HTML versions of the Article
Fifty million years of beetle evolution along the Antarctic Polar Front
Global cooling and glacialâinterglacial cycles since Antarcticaâs isolation have been responsible for the diversification of the regionâs marine fauna. By contrast, these same Earth system processes are thought to have played little role terrestrially, other than driving widespread extinctions. Here, we show that on islands along the Antarctic Polar Front, paleoclimatic processes have been key to diversification of one of the worldâs most geographically isolated and unique groups of herbivorous beetlesâEctemnorhinini weevils. Combining phylogenomic, phylogenetic, and phylogeographic approaches, we demonstrate that these weevils colonized the sub-Antarctic islands from Africa at least 50 Ma ago and repeatedly dispersed among them. As the climate cooled from the mid-Miocene, diversification of the beetles accelerated, resulting in two species-rich clades. One of these clades specialized to feed on cryptogams, typical of the polar habitats that came to prevail under Miocene conditions yet remarkable as a food source for any beetle. This cladeâs most unusual representative is a marine weevil currently undergoing further speciation. The other clade retained the more common weevil habit of feeding on angiosperms, which likely survived glaciation in isolated refugia. Diversification of Ectemnorhinini weevils occurred in synchrony with many other Antarctic radiations, including penguins and notothenioid fishes, and coincided with major environmental changes. Our results thus indicate that geoclimatically driven diversification has progressed similarly for Antarctic marine and terrestrial organisms since the Miocene, potentially constituting a general biodiversity paradigm that should be sought broadly for the regionâs taxa
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