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BMC Evolutionary Biology Oct 2011Within the Coleoptera, the largest order in the animal kingdom, the exclusively herbivorous Chrysomelidae are recognized as one of the most species rich beetle families....
BACKGROUND
Within the Coleoptera, the largest order in the animal kingdom, the exclusively herbivorous Chrysomelidae are recognized as one of the most species rich beetle families. The evolutionary processes that have fueled radiation into the more than thirty-five thousand currently recognized leaf beetle species remain partly unresolved. The prominent role of leaf beetles in the insect world, their omnipresence across all terrestrial biomes and their economic importance as common agricultural pest organisms make this family particularly interesting for studying the mechanisms that drive diversification. Here we specifically focus on two ecotypes of the alpine leaf beetle Oreina speciosissima (Scop.), which have been shown to exhibit morphological differences in male genitalia roughly corresponding to the subspecies Oreina speciosissima sensu stricto and Oreina speciosissima troglodytes. In general the two ecotypes segregate along an elevation gradient and by host plants: Oreina speciosissima sensu stricto colonizes high forb vegetation at low altitude and Oreina speciosissima troglodytes is found in stone run vegetation at higher elevations. Both host plants and leaf beetles have a patchy geographical distribution. Through use of gene sequencing and genome fingerprinting (AFLP) we analyzed the genetic structure and habitat use of Oreina speciosissima populations from the Swiss Alps to examine whether the two ecotypes have a genetic basis. By investigating a wide range of altitudes and focusing on the structuring effect of habitat types, we aim to provide answers regarding the factors that drive adaptive radiation in this phytophagous leaf beetle.
RESULTS
While little phylogenetic resolution was observed based on the sequencing of four DNA regions, the topology and clustering resulting from AFLP genotyping grouped specimens according to their habitat, mostly defined by plant associations. A few specimens with intermediate morphologies clustered with one of the two ecotypes or formed separate clusters consistent with habitat differences. These results were discussed in an ecological speciation framework.
CONCLUSIONS
The question of whether this case of ecological differentiation occurred in sympatry or allopatry remains open. Still, the observed pattern points towards ongoing divergence between the two ecotypes which is likely driven by a recent shift in host plant use.
Topics: Adaptation, Biological; Amplified Fragment Length Polymorphism Analysis; Animals; Asteraceae; Coleoptera; DNA, Mitochondrial; DNA, Ribosomal Spacer; Ecosystem; Genetic Speciation; Herbivory; Male
PubMed: 22014288
DOI: 10.1186/1471-2148-11-310 -
Journal of Embryology and Experimental... Jun 1979Eggs of the pea-beetle Callosobruchus were divided into two at different stages of development. Both fragments were allowed to develop into partial larvae. The segment...
The specification of metameric order in the insect Callosobruchus maculatus Fabr. (Coleoptera). I. Incomplete segment patterns can result from constriction-induced cytological damage to the egg.
Eggs of the pea-beetle Callosobruchus were divided into two at different stages of development. Both fragments were allowed to develop into partial larvae. The segment patterns of normal and partial larvae are described using cuticular markers of cell differentiation. To study the contribution of cytological damage to the segment gap phenomenon three different types of constriction were performed: complete and incomplete permanent constriction and complete temporary constriction. Changes in the structure of the egg can produce absence of segments resulting from two different effects. First, partial absence of segments results from a decreased egg circumference in the constriction region and involves the disturbance of a morphogenetic process (dorsal closure). Secondly, cytological damage can result in a gap between two arrays of segments. The loss of segments in the gap occurred in two different ways. In a spatial segment gap the two arrays of segments were physically discontinuous, whereas in a non-spatial gap the segments bordering the gap were juxtaposed in a physically continuous cuticle. The extent to which the gap phenomenon can be attributed to cytological damage is discussed. We also discuss, on the basis of certain dorsal defects, a possible stepwise specification of the dorsal transverse cuticular pattern.
Topics: Animals; Coleoptera; Constriction; Female; Larva; Morphogenesis; Ovum
PubMed: 573305
DOI: No ID Found -
Cladistics : the International Journal... Oct 2020In order to place a newly discovered species Antigracilus costatus gen. sp. n. from the Lower Cretaceous Yixian Formation (China) and to assess previously unplaced...
In order to place a newly discovered species Antigracilus costatus gen. sp. n. from the Lower Cretaceous Yixian Formation (China) and to assess previously unplaced fossil taxa, we investigated the relationships of extant and extinct lineages of Histeridae based on three data sets: (i) 69 morphological characters belonging to 48 taxa (representing all 11 subfamilies and 15 of 17 tribes of modern Histeridae); (ii) partitioned alignment of 6030 bp from downloaded nucleotide sequences (28S, CAD, COI, 18S) of 50 taxa (representing 10 subfamilies and 15 of 17 tribes of modern Histeridae); and (iii) a combined morphological and molecular dataset for 75 taxa. Phylogenetic analyses of the morphology and combined matrices recovered the new Lower Cretaceous taxon as a sister group to remaining Histeridae and it is placed in †Antigracilinae subfam. n. †Antigracilinae constitutes the earliest record of Histeridae from the Lower Cretaceous Yixian Formation (∼125 Myr), backdating the minimum age of the family by 25 Myr from the earliest Cenomanian (~99 Myr) to the Barremian of the Cretaceous Period. Our molecular phylogeny supports Histeridae to be divided into seven different clades, with currently recognised subfamilies Abraeinae (sensu lato), Saprininae, Chlamydopsinae, and Histerinae (sensu lato) recovered as monophyletic, while Dendrophilinae, Onthophilinae, and Tribalinae are polyphyletic taxa. The Burmese amber species †Pantostictus burmanicus Poinar & Brown is placed as a sister group to the tribe Plegaderini (Abraeinae) and was assigned as a new tribe Pantostictini trib. n. Both molecular and combined phylogenies recovered the subfamilies Trypanaeinae and Trypeticinae deeply within the subfamily Abraeinae (sensu lato), and they are downgraded into Trypanaeini stat. n. and Trypeticini stat. n.
Topics: Abdomen; Animals; Coleoptera; Evolution, Molecular; Extremities; Fossils; Head; Male; Microscopy, Electron, Scanning; Mouth; Phylogeny; Thorax
PubMed: 34618954
DOI: 10.1111/cla.12418 -
Zootaxa Mar 2021Scaphidium is a rove beetle genus (Coleoptera: Staphylinidae) of remarkable and diverse colouration. Although most of Scaphidium species are easily distinguished by the...
Scaphidium is a rove beetle genus (Coleoptera: Staphylinidae) of remarkable and diverse colouration. Although most of Scaphidium species are easily distinguished by the colour patterns, there exist some confusing variants, which may introduce bias into rapid identification. Molecular identification using the mitochondrial genome is a reliable approach that overcomes the shortcoming of morphological recognition for those who have limited experience in species-level identification. Here we described the nearly complete mitochondrial genome of Scaphidium formosanum Pic, 1915, a species with variant colour types, and tested the reliability of identification based on mitochondrial genes by both gene-wise metrics and phylogenetic analyses. In this study, the 17,455 bp mitochondrial genome of S. formosanum is composed of 13 protein-coding genes (PCGs), 22 tRNAs, and 2 rRNAs. All PCGs start with typical ATN codons, except Nad4l which began with the TTG codon. The gene order is consistent with the typical linear arrangement of the published rove beetle mitochondrial genomes. The nucleotide composition is highly A+T biased (76.42%): A - 39.99%, T - 36.44%, C - 15.08%, and G - 8.49%. Multiple metrics support that our sample has a higher similarity to S. quadrimaculatum than to other species. Maximum likelihood trees confirm the placement of our sample as the closest related entity to S. quadrimaculatum. We conclude that the mitochondrial genome has a reliable performance in molecular identification in this case.
Topics: Animals; Coleoptera; Gene Order; Genome, Mitochondrial; Phylogeny; Reproducibility of Results
PubMed: 33756920
DOI: 10.11646/zootaxa.4941.4.2 -
Environmental Entomology Dec 2021Semiochemical background in the environment can influence insect orientation to release points of the same or different semiochemicals. endo-Brevicomin is a pheromone...
Semiochemical background in the environment can influence insect orientation to release points of the same or different semiochemicals. endo-Brevicomin is a pheromone component of the tree-killing bark beetle Dendroctonus frontalis Zimmermann (Coleoptera: Curculionidae: Scolytinae) that has a biphasic dose-response curve, enhancing attraction at low release rates but reducing attraction at high rates. We investigated the effect of artificial manipulation of background levels of endo-brevicomin on D. frontalis responses to sources of aggregation attractant in the field. Traps baited with the aggregation pheromone component frontalin and the host odor alpha-pinene were deployed either with or without a background of endo-brevicomin produced by three surrounding dispensers of this semiochemical each located 20 m away. Two tested levels of endo-brevicomin background caused catches to increase by an order of magnitude above those in the absence of background. Presence of background also altered the beetles' biphasic dose-response when endo-brevicomin dispensers were added to traps. Background reduced or concealed attraction-enhancement otherwise observed for low-release dispensers added to traps, and it decreased the release rate necessary to produce reductions in catches. We propose that spatial variability in abundance of natural, background sources of endo-brevicomin in the environment (i.e., infested trees) is a cause of the observed variability in effects of endo-brevicomin dispensers on southern pine beetle behavior in the field. Furthermore, our results illustrate the potential complexity of the density-dependent effects of biphasic pheromone components on bark beetle mass attack and colonization behavior.
Topics: Animals; Bridged Bicyclo Compounds, Heterocyclic; Coleoptera; Pheromones; Pinus; Weevils
PubMed: 34487153
DOI: 10.1093/ee/nvab092 -
Molecular Phylogenetics and Evolution Oct 2021Marine rockpools are isolated patches of habitat in the supratidal environment (the so-called splash zone), at the transition between sea and land, found along the rocky...
Marine rockpools are isolated patches of habitat in the supratidal environment (the so-called splash zone), at the transition between sea and land, found along the rocky shores worldwide and characterized by harsh conditions for life. Nonetheless, few specialized invertebrates successfully colonized this peculiar environment. Among them several members of the water beetles Ochthebius Leach, 1815, subgenus Cobalius Rey (1886), which are found almost exclusively in supratidal and upper-most intertidal marine rockpools from the eastern Atlantic Ocean (Cape Verde, Canary Islands and Morocco, Madeira, Azores) throughout the whole Mediterranean basin. The subgenus Cobalius before 2020 was considered to include ten valid species, based on morphological differences. In late 2020, four additional new species were described. However, recent molecular phylogenetic studies have uncovered further cryptic diversity suggesting the presence of multiple undetected species within this group, highlighting that the species boundaries remain unclear and systematics and taxonomy are in need of revision. In this study we provide a molecular phylogeny based on DNA sequence data from mitochondrial and nuclear genes obtained from ten described species belonging to the subgenus Cobalius, and extensive taxon sampling, in order to better understand the phylogenetic relationships within this genus and to infer the biogeographic processes behind its diversification. We also used a molecular clock to define a time window for diversification of distinct clades within the subgenus, and explore aspects of its evolutionary history. Finally, we used three species delimitation methods (PTP, GMYC and ABGD) to clarify taxonomy and validate species boundaries. Our phylogenetic and biogeographic results identified sixteen independent lineages grouped in four main clades and the possible origin of Cobalius was estimated to be in the Early Miocene (~22 Mya) in W Mediterranean area. Moreover, species delimitation methods suggest there are between 16 and 24 putative species, most of them diverged during the Late Miocene, Pliocene and Pleistocene (6.0-0.11 Mya).
Topics: Animals; Base Sequence; Bayes Theorem; Coleoptera; DNA, Mitochondrial; Ecosystem; Phylogeny; Portugal
PubMed: 34224850
DOI: 10.1016/j.ympev.2021.107243 -
Zootaxa May 2020The darkling beetle genus Hypogena Dejean, 1834 (Tenebrionidae: Tenebrioninae) is revised. Hypogena is entirely composed of dorsoventrally flattened species that live...
The darkling beetle genus Hypogena Dejean, 1834 (Tenebrionidae: Tenebrioninae) is revised. Hypogena is entirely composed of dorsoventrally flattened species that live subcortically in dead trees. This genus is generally identified by male specific characters, particularly the presence of cephalic horns. Hypogena is currently placed within the tribe Triboliini Gistel, 1848. However, several previously overlooked morphological characters call into question its placement within the tribe. A morphological matrix of 94 external adult characters was assembled to examine species relationships and boundaries. The resulting phylogeny is presented. Thirteen Hypogena species were previously recognized as valid, including Hypogena marginalis Doyen Poinar from Dominican amber. Four previously unidentified species are described in this study: Hypogena akuma sp. nov. (Brazil), Hypogena cryptica sp. nov. (Mexico), Hypogena hirsuta sp. nov. (Ecuador), and Hypogena reburra sp. nov. (Colombia). Lectotypes are designated for Hypogena depressa (Champion, 1886), Hypogena dejeani (Champion, 1886), Hypogena canaliculata (Champion, 1886), and Hypogena vacca (Fabricius, 1801). A neotype is designated for Tenebrio biimpressus (Latreille, 1833) (type species of Hypogena, synonymized under Hypogena brasilica (Perty)) in order to maintain stability within the genus.
Topics: Animal Distribution; Animals; Coleoptera; Male
PubMed: 33055742
DOI: 10.11646/zootaxa.4780.2.1 -
GigaScience Dec 2017Fireflies are a family of insects within the beetle order Coleoptera, or winged beetles, and they are one of the most well-known and loved insect species because of...
BACKGROUND
Fireflies are a family of insects within the beetle order Coleoptera, or winged beetles, and they are one of the most well-known and loved insect species because of their bioluminescence. However, the firefly is in danger of extinction because of the massive destruction of its living environment. In order to improve the understanding of fireflies and protect them effectively, we sequenced the whole genome of the terrestrial firefly Pyrocoelia pectoralis.
FINDINGS
Here, we developed a highly reliable genome resource for the terrestrial firefly Pyrocoelia pectoralis (E. Oliv., 1883; Coleoptera: Lampyridae) using single molecule real time (SMRT) sequencing on the PacBio Sequel platform. In total, 57.8 Gb of long reads were generated and assembled into a 760.4-Mb genome, which is close to the estimated genome size and covered 98.7% complete and 0.7% partial insect Benchmarking Universal Single-Copy Orthologs. The k-mer analysis showed that this genome is highly heterozygous. However, our long-read assembly demonstrates continuousness with a contig N50 length of 3.04 Mb and the longest contig length of 13.69 Mb. Furthermore, 135 589 SSRs and 341 Mb of repeat sequences were detected. A total of 23 092 genes were predicted; 88.44% of genes were annotated with one or more related functions.
CONCLUSIONS
We assembled a high-quality firefly genome, which will not only provide insights into the conservation and biodiversity of fireflies, but also provide a wealth of information to study the mechanisms of their sexual communication, bio-luminescence, and evolution.
Topics: Animals; Chromosome Mapping; Female; Fireflies; Genome Size; Genome, Insect; Molecular Sequence Annotation; Whole Genome Sequencing
PubMed: 29186486
DOI: 10.1093/gigascience/gix112 -
Genes Oct 2019Gene expression profiles can change dramatically between sexes and sex bias may contribute specific macroevolutionary dynamics for sex-biased genes. However, these...
Gene expression profiles can change dramatically between sexes and sex bias may contribute specific macroevolutionary dynamics for sex-biased genes. However, these dynamics are poorly understood at large evolutionary scales due to the paucity of studies that have assessed orthology and functional homology for sex-biased genes and the pleiotropic effects possibly constraining their evolutionary potential. Here, we explore the correlation of sex-biased expression with macroevolutionary processes that are associated with sex-biased genes, including duplications and accelerated evolutionary rates. Specifically, we examined these traits in a group of 44 genes that orchestrate sperm individualization during spermatogenesis, with both unbiased and sex-biased expression. We studied these genes in the broad evolutionary framework of the Insecta, with a particular focus on beetles (order Coleoptera). We studied data mined from 119 insect genomes, including 6 beetle models, and from 19 additional beetle transcriptomes. For the subset of physically and/or genetically interacting proteins, we also analyzed how their network structure may condition the mode of gene evolution. The collection of genes was highly heterogeneous in duplication status, evolutionary rates, and rate stability, but there was statistical evidence for sex bias correlated with faster evolutionary rates, consistent with theoretical predictions. Faster rates were also correlated with clocklike (insect amino acids) and non-clocklike (beetle nucleotides) substitution patterns in these genes. Statistical associations (higher rates for central nodes) or lack thereof (centrality of duplicated genes) were in contrast to some current evolutionary hypotheses, highlighting the need for more research on these topics.
Topics: Animals; Coleoptera; Databases, Genetic; Evolution, Molecular; Gene Regulatory Networks; Genes, Insect; Insecta; Male; Phylogeny; Sex Characteristics; Spermatogenesis; Spermatozoa; Transcriptome
PubMed: 31590243
DOI: 10.3390/genes10100776 -
Journal of Economic Entomology Apr 2018Life table and predation data were collected for Coccinella septempunctata (Linnaeus) (Coleoptera: Coccinellidae) feeding on three different host aphid species, Aphis... (Comparative Study)
Comparative Study
Life table and predation data were collected for Coccinella septempunctata (Linnaeus) (Coleoptera: Coccinellidae) feeding on three different host aphid species, Aphis craccivora (Koch) (Hemiptera: Aphididae), Lipaphis erysimi (Kaltenbach) (Hemiptera: Aphididae), and Myzus persicae (Sulzer) (Hemiptera: Aphididae), under laboratory conditions, using age-stage, two-sex life table. The preadult developmental period of C. septempunctata was the shortest on M. persicae (21.12 d) and the longest on A. craccivora (28.81 d). Net reproductive rate (R0) ranged from 77.31 offspring per individual on A. craccivora to 165.97 offspring per individual on M. persicae. Mean generation time (T) ranged from 39.10 d on M. persicae to 51.96 d on L. erysimi. Values of the intrinsic rate of increase (r) decreased in the order M. persicae, A. craccivora, and L. erysimi (0.1302, 0.0864 and 0.0848 d-1, respectively). The highest finite rate of increase (λ) was observed on M. persicae (1.1391 d-1) and the lowest was observed on A. craccivora and L. erysimi (1.0903 and 1.0885 d-1, respectively). This information will be useful in relation to the mass rearing of C. septempunctata in biological control systems.
Topics: Animals; Aphids; Coleoptera; Female; Life Tables; Male; Pest Control, Biological; Reproduction
PubMed: 29490056
DOI: 10.1093/jee/toy012