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The monophyletic status of the genus Oreina as well as its phylogenetic relation to the closely related genera Chrysolina, Crosita and Cyrtonus has been debated for several decades. To assess the status of the genus and understand its evolutionary history, we performed a museomics study on 148 museum specimens belonging to 25 of the 28 described Oreina species as well as 19 other chrysomelid species, mainly from the genus Chrysolina. Using innovative molecular methods relying on hyRAD hybridization capture, we succeeded in recovering 2235 shared nuclear loci. Phylogenomic analyses clearly demonstrated that Oreina species form a clade separated from Chrysolina. These analyses also revealed the position of Chrysolina fastuosa outside of the genus Chrysolina, supporting the following taxonomic status updates: Fastastat. rev., Fasta fastuosacomb. nov. Within the genus Oreina, we further propose the synonymization of Oreina (Frigidorina) syn. n. and Oreina (Virgulatorina) syn. n. with Oreina (Chrysochloa). Divergence time and ancestral range estimations suggested that Oreina originated approximately 53 Ma in the Alps. Ancestral host plant reconstruction revealed key shifts during Oreina diversification. Overall, our study reinforces the importance of museum collections for molecular analysis and the effectiveness of hybridization capture approaches for conducting phylogenomic studies and finely investigating controversial taxonomic debates. [ABSTRACT FROM AUTHOR]

Ecological specialists constitute relevant case studies for understanding the mechanisms, potential and limitations of evolution. The species-rich and strictly myrmecophagous spiders of the genus Zodarion show diversified defence mechanisms, including myrmecomorphy of different ant species and nocturnality. Through Hybridization Capture Using RAD Probes (hyRAD), a phylogenomic technique designed for sequencing poorly preserved specimens, we reconstructed a phylogeny of Zodarion using 52 (approx. a third of the nominal) species that cover its phylogenetic and distributional diversity. We then estimated the evolution of body size and colour, traits that have diversified noticeably and are linked to defence mechanisms, across the group. Our genomic matrix of 300 loci led to a well-supported phylogenetic hypothesis that uncovered two main clades inside Zodarion. Ancestral state estimation revealed the highly dynamic evolution of body size and colour across the group, with multiple transitions and convergences in both traits, which we propose is likely indicative of multiple transitions in ant specialization across the genus. Our study will allow the informed targeted selection of Zodarion taxa of special interest for research into the group's remarkable adaptations to ant specialization. It also exemplifies the utility of hyRAD for phylogenetic studies using museum material. [ABSTRACT FROM AUTHOR]

In this study the aim was to resolve the taxonomy of several species of Argyria Hübner (Pyraloidea, Crambinae) with previously unrecognised morphological variation. By analysing the DNA barcode (COI-5P) in numerous specimens, the aim was to reconstruct phylogenetic relationships between species, to provide better evidence for synonymies, and to circumscribe their geographical distribution. Using an innovative DNA hybridisation capture protocol, the DNA barcode of the lectotype of Argyria lacteella (Fabricius, 1794) was partially recovered for comparison with the 229 DNA barcode sequences of Argyria specimens available in the Barcode of Life Datasystems, and this firmly establishes the identity of the species. The same protocol was used for the following type specimens: the Argyria abronalis (Walker, 1859) holo-type, thus confirming the synonymy of this name with A. lacteella, the holotype of A. lusella (Zeller, 1863), syn. rev., the holotype of A. multifacta Dyar, 1914, syn. nov. newly synonymised with A. lacteella, and a specimen of Argyria diplomochalis Dyar, 1913, collected in 1992. In addition, nine specimens of A. lacteella, A. diplomochalis, A. centrifugens Dyar, 1914 and A. gonogramma Dyar, 1915, from North to South America were sampled using classical COI amplification and Sanger sequencing. Argyria gonogramma Dyar, described from Bermuda, is the name to be applied to the more widespread North American species formerly identified as A. lacteella. Following morphological study of its holotype, Argyria vestalis Butler, 1878, syn. nov. is also synonymised with A. lacteella. The name A. pusillalis Hübner, 1818, is considered a nomen dubium associated with A. gonogramma. The adult morphology is diagnosed and illustrated, and distributions are plotted for A. lacteella, A. diplomochalis, A. centrifugens, and A. gonogramma based on slightly more than 800 specimens. For the first time, DNA barcode sequences are provided for the Antillean A. diplomochalis. This work provides a modified, improved protocol for the efficient hybrid capture enrichment of DNA barcodes from 18th and 19th century type specimens in order to solve taxonomic issues in Lepidoptera. [ABSTRACT FROM AUTHOR]

Advances in phylogenomics contribute toward resolving long-standing evolutionary questions. Notwithstanding, genetic diversity contained within more than a billion biological specimens deposited in natural history museums remains recalcitrant to analysis owing to challenges posed by its intrinsically degraded nature. Yet that tantalizing resource could be critical in overcoming taxon sampling constraints hindering our ability to address major evolutionary questions. We addressed this impediment by developing phyloHyRAD, a new bioinformatic pipeline enabling locus recovery at a broad evolutionary scale from HyRAD-X exome capture of museum specimens of low DNA integrity using a benchtop RAD-derived exome-complexity-reduction probe set developed from high DNA integrity specimens. Our new pipeline can also successfully align raw RNAseq transcriptomic and ultraconserved element reads with the RAD-derived probe catalog. Using this method, we generated a robust timetree for Carabinae beetles, the lack of which had precluded study of macroevolutionary trends pertaining to their biogeography and wing-morphology evolution. We successfully recovered up to 2,945 loci with a mean of 1,788 loci across the exome of specimens of varying age. Coverage was not significantly linked to specimen age, demonstrating the wide exploitability of museum specimens. We also recovered fragmentary mitogenomes compatible with Sanger-sequenced mtDNA. Our phylogenomic timetree revealed a Lower Cretaceous origin for crown group Carabinae, with the extinct Aplothorax Waterhouse, 1841 nested within the genus Calosoma Weber, 1801 demonstrating the junior synonymy of Aplothorax   syn. nov. , resulting in the new combination Calosoma burchellii (Waterhouse, 1841) comb. nov. This study compellingly illustrates that HyRAD-X and phyloHyRAD efficiently provide genomic-level data sets informative at deep evolutionary scales. [ABSTRACT FROM AUTHOR]

The Alps played an important role in the biogeography of European plants and acted as a refugium for numerous species during the interglacial cycles. We investigated Nuphar pumila, one of the most emblematic glacial relicts of the Alps, by carrying out exhaustive literature and field surveys to collect relevant data on its distribution and threats. We further evaluated the level of introgression with the closely related N. lutea based on microsatellite data from natural populations across the Alps as well as from all ex situ collections and reintroductions in Switzerland. According to our results, more than 60% of the known N. pumila populations went extinct, and the species currently presents 37 natural populations in the investigated area. A large number of populations were affected by eutrophication (69%) and hybridization with N. lutea (53%). Priority should be given to the in situ conservation of genetically pure populations, while ex situ cultures should be applied to nearly extinct populations and the genetically pure individuals still present in hybrid populations. N. pumila is an excellent representative of the wetland/aquatic glacial relicts that are particularly affected by the combination of climate change and habitat degradation. International integration of research and conservation programs is needed to limit the decline of such rare species in the Alps. [ABSTRACT FROM AUTHOR]

Plants protect themselves against herbivore attacks through a myriad of physical structures and toxic secondary metabolites. Together with abiotic factors, herbivores are expected to modulate plant defence strategies within plant assemblages. Because the abundance of insect herbivore decreases in colder environments, the palatability of plants in communities at higher elevation should shift in response to both abiotic and biotic factors., We inventoried grasshopper communities to document changes in herbivore abundance along elevation gradients and quantified associated shifts in plant palatability. We measured plant palatability by measuring the growth of Spodoptera littoralis generalist caterpillars fed with the leaves of 172 plant species. We related plant palatability to leaf traits and elevation at the species and community levels., In congruence with the decrease in grasshopper abundance with elevation, we found that the mean palatability level of plant communities increases with elevation. In addition, plant palatability was negatively associated with the community-weighted mean of leaf dry matter content. At the species level, plants with high carbon-to-nitrogen ratio were less palatable, while we found no effect of species mean elevation on plant palatability., Synthesis. Our results suggest that plant communities at higher elevation are composed of species that are generally more palatable for insect herbivores. Shift in plant palatability with elevation may thus be the outcome of a relaxation of the in situ herbivore pressure and changes in abiotic conditions. [ABSTRACT FROM AUTHOR]

Field studies and conceptual work on hybridization-mediated extinction risk in climate relicts are extremely rare. Nuphar pumila (Nymphaeaceae) is one of the most emblematic climate relicts in Europe with few isolated populations in the Alpine arc. The extent of introgression with related lowland and generalist species Nuphar lutea has never been studied using molecular methods. All biogeographical regions where N. pumila naturally occurs in the neighbourhood of the Alpine arc were sampled and studied using nuclear microsatellite markers. Furthermore, we used forward-in-time simulations and Approximate Bayesian Computation to check whether an introgression scenario fits with the observed admixture patterns and estimated the demographic parameters associated with this process. Our study confirms ongoing hybridization between N. pumila and N. lutea and validates it by the use of population models. More than 40 % of investigated N. pumila individuals were admixed and hybrids were found in over 60 % of studied populations. The introgression is bidirectional and is most likely a result of very recent gene flow. Our work provides strong evidence for rapid extinction risk and demographic swamping between specialized climatic relicts and closely related generalists. The remaining pure populations of N. pumila are rare in the Alpine arc and deserve high conservation priority. [ABSTRACT FROM AUTHOR]

The hypothesis that constitutive and inducible plant resistance against herbivores should trade-off because they use the same resources and impose costs to plant fitness has been postulated for a long time. Negative correlations between modes of deployment of resistance and defences have been observed across and within species in common garden experiments. It was therefore tested whether that pattern of resistance across genotypes follows a similar variation in patterns of gene expression and chemical defence production. Using the genetically tractable model Arabidopsis thaliana and different modes of induction, including the generalist herbivore Spodoptera littoralis, the specialist herbivore Pieris brassicae, and jasmonate application, constitutive and inducibility of resistance was measured across seven A. thaliana accessions that were previously selected based on constitutive levels of defence gene expression. According to theory, it was found that modes of resistance traded-off among accessions, particularly against S. littoralis, in which accessions investing in high constitutive resistance did not increase it substantially after attack and vice-versa. Accordingly, the average expression of eight genes involved in glucosinolate production negatively predicted larval growth across the seven accessions. Glucosinolate production and genes related to defence induction on healthy and herbivore-damaged plants were measured next. Surprisingly, only a partial correlation between glucosinolate production, gene expression, and the herbivore resistance results was found. These results suggest that the defence outcome of plants against herbivores goes beyond individual molecules or genes but stands on a complex network of interactions. [ABSTRACT FROM AUTHOR]

Traits that mediate species interactions are evolutionarily shaped by biotic and abiotic drivers, yet we know relatively little about the relative importance of these factors. Herbivore pressure, along with resource availability and 'third-party' mutualists, are hypothesized to play a major role in the evolution of plant defence traits. Here, we used the model system Plantago lanceolata, which grows along steep elevation gradients in the Swiss Alps, to investigate the effect of elevation, herbivore pressure, mycorrhizal inoculation and temperature on plant resistance. Over a 1200 m elevation gradient, the levels of herbivory and iridoid glycosides (IGs) declined with increasing elevation. By planting seedlings at three different elevations, we further showed that both low-elevation growing conditions and mycorrhizal inoculation resulted in increased plant resistance to herbivores. Finally, using a temperature-controlled experiment comparing high- and low-elevation ecotypes, we showed that high-elevation ecotypes are less resistant to herbivory, and that lower temperatures impair IGs deployment after herbivore attack. We thus propose that both lower herbivore pressure, and colder temperatures relax the defense syndrome of high elevation plants. [ABSTRACT FROM AUTHOR]

Genetic manipulation of plant volatile emissions is a promising tool to enhance plant defences against herbivores. However, the potential costs associated with the manipulation of specific volatile synthase genes are unknown. Therefore, we investigated the physiological and ecological effects of transforming a maize line with a terpene synthase gene in field and laboratory assays, both above- and below ground. The transformation, which resulted in the constitutive emission of ( E)-β-caryophyllene and α-humulene, was found to compromise seed germination, plant growth and yield. These physiological costs provide a possible explanation for the inducibility of an ( E)-β-caryophyllene-synthase gene in wild and cultivated maize. The overexpression of the terpene synthase gene did not impair plant resistance nor volatile emission. However, constitutive terpenoid emission increased plant apparency to herbivores, including adults and larvae of the above ground pest Spodoptera frugiperda, resulting in an increase in leaf damage. Although terpenoid overproducing lines were also attractive to the specialist root herbivore Diabrotica virgifera virgifera below ground, they did not suffer more root damage in the field, possibly because of the enhanced attraction of entomopathogenic nematodes. Furthermore, fewer adults of the root herbivore Diabrotica undecimpunctata howardii were found to emerge near plants that emitted ( E)-β-caryophyllene and α-humulene. Yet, overall, under the given field conditions, the costs of constitutive volatile production overshadowed its benefits. This study highlights the need for a thorough assessment of the physiological and ecological consequences of genetically engineering plant signals in the field to determine the potential of this approach for sustainable pest management strategies. [ABSTRACT FROM AUTHOR]