Science Enabled by Specimen Data

Yoon, S., and W.-H. Lee. 2022. Spatial analysis of climatic and dispersion characteristics of Xylella fastidiosa outbreak by insect vectors. Journal of Asia-Pacific Entomology: 102011. https://doi.org/10.1016/j.aspen.2022.102011

Xylella fastidiosa is a pathogen that causes fatal plant diseases and damage to horticultural crops. Establishing the basic parameters is necessary to assess the risk of disease outbreaks as there are concerns about the spread of X. fastidiosa. This is done by analyzing the climatic characteristics and distribution patterns of X. fastidiosa and related insect vectors. In this study, we aimed to derive the common climatic characteristics of X. fastidiosa and three major insect vectors by using a statistical density function for four climatic factors. In addition, the distance between the occurrence areas was calculated spatiotemporally and classified into natural and anthropogenic spread. The optimal climatic conditions identified for X. fastidiosa and the insect vectors were similar, suggesting a high potential for X. fastidiosa spread when both occur in a neighborhood area. X. fastidiosa spread mostly depends on anthropogenic pathways, but natural spread by insect vectors could increase. This study provides necessary insights for the risk assessment of X. fastidiosa spread based on climate similarity and spread patterns.

Li, X., and J. J. Wiens. 2022. Estimating Global Biodiversity: the Role of Cryptic Insect Species. Systematic Biology. https://doi.org/10.1093/sysbio/syac069

Abstract How many species are there on Earth and to what groups do these species belong? These fundamental questions span systematics, ecology, and evolutionary biology. Yet, recent estimates of overall global biodiversity have ranged wildly, from the low millions to the trillions. Insects are a pivotal group for these estimates. Insects make up roughly half of currently described extant species (across all groups), with ~1 million described species. Insect diversity is also crucial because many other taxa have species that may be unique to each insect host species, including bacteria, apicomplexan protists, microsporidian fungi, nematodes, and mites. Several projections of total insect diversity (described and undescribed) have converged on ~6 million species. However, these projections have not incorporated the morphologically cryptic species revealed by molecular data. Here, we estimate the extent of cryptic insect diversity. We perform a systematic review of studies that used explicit species-delimitation methods with multi-locus data. We estimate that each morphology-based insect species contains (on average) 3.1 cryptic species. We then use these estimates to project the overall number of species on Earth and their distribution among major groups. Our estimates suggest that overall global biodiversity may range from 563 million to 2.2 billion species. [Biodiversity; cryptic species; insects; species delimitation; species richness]

YUNAKOV, N. 2022. A review of the genus Brachysomus Schoenherr (Coleoptera: Curculionidae: Entiminae). Zootaxa 5193: 1–165. https://doi.org/10.11646/zootaxa.5193.1.1

The genus Brachysomus Schoenherr, 1823 is reviewed. A comparative morphological study of adults from 56 Brachysomus species is provided. Redescriptions, diagnoses and identification keys are given. Descriptions of two new species are provided: B. (s. str.) podlussanyi sp. n. from Greece and B. (s. str.) pseudosetiger sp. n. from Bulgaria, which appear to be closely related to B. (s. str.) mihoki Penecke, 1914. Females of B. (s. str.) longipterus Białooki, 2007 are described. The poorly known B. (Hippomias) moczarskii Penecke, 1924 is restored from synonymy with B. (H.) oertzeni Faust, 1889. New synonyms: B. (s. str.) echinatus (Bonsdorff, 1785) = B. (s. str.) hirsutus Iablokoff-Khnzorian, 1958 syn. n. New combinations: Brachysomus (s. str.) lituratus (Reitter, 1884) comb. n. from Foucartia Jacquelin du Val, 1854; Eurosphalmus tenuicollis (Yunakov, 2006) comb. n. from Brachysomus, Eurosphalmus cribrarius (Białooki, 2007) comb. n. from Brachysomus, Nanomias skodai (Białooki, 2007) comb. n. from Brachysomus, and Chiloneus bonnairei (Hoffmann, 1942) comb. n. from Brachysomus. Lectotypes are designated for: Strophosomus hirtus Boheman, 1845; Brachysomus ornatus Stierlin, 1892; B. bensae Stierlin, 1893; Platytarsus fasciatus Stierlin, 1899; and P. setiger Gyllenhal, 1840. For each species, all known localities are presented on a distribution map. Ecological preferences of Brachysomus species are specified. First records of Brachysomus (s. str.) fremuthi Košťál, 1991 from Romania, B. (Hippomias) carpathicus Košťál, 1992 from Serbia, and B. (H.) ponticus Apfelbeck, 1898 from Greece are given.

Marcussen, T., H. E. Ballard, J. Danihelka, A. R. Flores, M. V. Nicola, and J. M. Watson. 2022. A Revised Phylogenetic Classification for Viola (Violaceae). Plants 11: 2224. https://doi.org/10.3390/plants11172224

The genus Viola (Violaceae) is among the 40–50 largest genera among angiosperms, yet its taxonomy has not been revised for nearly a century. In the most recent revision, by Wilhelm Becker in 1925, the then-known 400 species were distributed among 14 sections and numerous unranked groups. Here, we provide an updated, comprehensive classification of the genus, based on data from phylogeny, morphology, chromosome counts, and ploidy, and based on modern principles of monophyly. The revision is presented as an annotated global checklist of accepted species of Viola, an updated multigene phylogenetic network and an ITS phylogeny with denser taxon sampling, a brief summary of the taxonomic changes from Becker’s classification and their justification, a morphological binary key to the accepted subgenera, sections and subsections, and an account of each infrageneric subdivision with justifications for delimitation and rank including a description, a list of apomorphies, molecular phylogenies where possible or relevant, a distribution map, and a list of included species. We distribute the 664 species accepted by us into 2 subgenera, 31 sections, and 20 subsections. We erect one new subgenus of Viola (subg. Neoandinium, a replacement name for the illegitimate subg. Andinium), six new sections (sect. Abyssinium, sect. Himalayum, sect. Melvio, sect. Nematocaulon, sect. Spathulidium, sect. Xanthidium), and seven new subsections (subsect. Australasiaticae, subsect. Bulbosae, subsect. Clausenianae, subsect. Cleistogamae, subsect. Dispares, subsect. Formosanae, subsect. Pseudorupestres). Evolution within the genus is discussed in light of biogeography, the fossil record, morphology, and particular traits. Viola is among very few temperate and widespread genera that originated in South America. The biggest identified knowledge gaps for Viola concern the South American taxa, for which basic knowledge from phylogeny, chromosome counts, and fossil data is virtually absent. Viola has also never been subject to comprehensive anatomical study. Studies into seed anatomy and morphology are required to understand the fossil record of the genus.

Lu, L.-L., B.-H. Jiao, F. Qin, G. Xie, K.-Q. Lu, J.-F. Li, B. Sun, et al. 2022. Artemisia pollen dataset for exploring the potential ecological indicators in deep time. Earth System Science Data 14: 3961–3995. https://doi.org/10.5194/essd-14-3961-2022

Abstract. Artemisia, along with Chenopodiaceae, is the dominant component growing in the desert and dry grassland of the Northern Hemisphere. Artemisia pollen with its high productivity, wide distribution, and easy identification is usually regarded as an eco-indicator for assessing aridity and distinguishing grassland from desert vegetation in terms of the pollen relative abundance ratio of Chenopodiaceae/Artemisia (C/A). Nevertheless, divergent opinions on the degree of aridity evaluated by Artemisia pollen have been circulating in the palynological community for a long time. To solve the confusion, we first selected 36 species from nine clades and three outgroups of Artemisia based on the phylogenetic framework, which attempts to cover the maximum range of pollen morphological variation. Then, sampling, experiments, photography, and measurements were taken using standard methods. Here, we present pollen datasets containing 4018 original pollen photographs, 9360 pollen morphological trait measurements, information on 30 858 source plant occurrences, and corresponding environmental factors. Hierarchical cluster analysis on pollen morphological traits was carried out to subdivide Artemisia pollen into three types. When plotting the three pollen types of Artemisia onto the global terrestrial biomes, different pollen types of Artemisia were found to have different habitat ranges. These findings change the traditional concept of Artemisia being restricted to arid and semi-arid environments. The data framework that we designed is open and expandable for new pollen data of Artemisia worldwide. In the future, linking pollen morphology with habitat via these pollen datasets will create additional knowledge that will increase the resolution of the ecological environment in the geological past. The Artemisia pollen datasets are freely available at Zenodo (https://doi.org/10.5281/zenodo.6900308; Lu et al., 2022).

Xu, X.-T., J. Szwedo, D.-Y. Huang, W.-Y.-D. Deng, M. Obroślak, F.-X. Wu, and T. Su. 2022. A New Genus of Spittlebugs (Hemiptera, Cercopidae) from the Eocene of Central Tibetan Plateau. Insects 13: 770. https://doi.org/10.3390/insects13090770

The superfamily Cercopoidea is commonly named as “spittlebugs”, as its nymphs produce a spittle mass to protect themselves. Cosmoscartini (Cercopoidea: Cercopidae) is a large and brightly colored Old World tropical tribe, including 11 genera. A new genus Nangamostethos gen. nov. (type species: Nangamostethostibetense sp. nov.) of Cosmoscartini is described from Niubao Formation, the late Eocene of central Tibetan Plateau (TP), China. Its placement is ensured by comparison with all the extant genera of the tribe Cosmoscartini. The new fossil represents one of few fossil Cercopidae species described from Asia. It is likely that Nangamostethos was extinct from the TP due to the regional aridification and an overturn of plant taxa in the late Paleogene.

Nygaard, M., A. Kopatz, J. M. D. Speed, M. D. Martin, T. Prestø, O. Kleven, and M. Bendiksby. 2022. Spatiotemporal monitoring of the rare northern dragonhead ( Dracocephalum ruyschiana , Lamiaceae) — SNP genotyping and environmental niche modeling herbarium specimens. Ecology and Evolution 12. https://doi.org/10.1002/ece3.9187

The species we have studied the spatiotemporal genetic change in the northern dragonhead, a plant species that has experienced a drastic population decline and habitat loss in Europe. We have added a temporal perspective to the monitoring of northern dragonhead in Norway by genotyping herbarium specimens up to 200 years old. We have also assessed whether northern dragonhead has achieved its potential distribution in Norway. To obtain the genotype data from 130 herbarium specimens collected from 1820 to 2008, mainly from Norway (83) but also beyond (47), we applied a microfluidic array consisting of 96 SNP markers. To assess temporal genetic change, we compared our new genotype data with existing data from modern samples. We used sample metadata and observational records to model the species' environmental niche and potential distribution in Norway. Our results show that the SNP array successfully genotyped all included herbarium specimens. Hence, with the appropriate design procedures, the SNP array technology appears highly promising for genotyping old herbarium specimens. The captured genetic diversity correlates negatively with distance from Norway. The historical‐modern comparisons reveal similar genetic structure and diversity across space and limited genetic change through time in Norway, providing no signs of any regional bottleneck (i.e., spatiotemporal stasis). The regional areas in Norway have remained genetically divergent, however, both from each other and more so from populations outside of Norway, rendering continued protection of the species in Norway relevant. The ENM results suggest that northern dragonhead has not fully achieved its potential distribution in Norway and corroborate that the species is anchored in warmer and drier habitats.

Hirabayashi, K., S. J. Murch, and L. A. E. Erland. 2022. Predicted impacts of climate change on wild and commercial berry habitats will have food security, conservation and agricultural implications. Science of The Total Environment 845: 157341. https://doi.org/10.1016/j.scitotenv.2022.157341

Climate change is now a reality and is altering ecosystems, with Canada experiencing 2–4 times the global average rate of warming. This will have a critical impact on berry cultivation and horticulture. Enhancing our understanding of how wild and cultivated berries will perform under changing climates will be essential to mitigating impacts on ecosystems, culture and food security. Our objective was to predict the impact of climate change on habitat suitability of four berry producing Vaccinium species: two species with primarily northern distributions (V. uliginosum, V. vitis-idaea), one species with a primarily southern distribution (V. oxycoccos), and the commercially cultivated V. macrocarpon. We used the maximum entropy (Maxent) model and the CMIP6 shared socioeconomic pathways (SSPs) 126 and 585 projected to 2041–2060 and 2061–2080. Wild species showed a uniform northward progression and expansion of suitable habitat. Our modeling predicts that suitable growing regions for commercial cranberries are also likely to shift with some farms becoming unsuitable for the current varieties and other regions becoming more suitable for cranberry farms. Both V. macrocarpon and V. oxycoccos showed a high dependence on precipitation-associated variables. Vaccinium vitis-idaea and V. uliginosum had a greater number of variables with smaller contributions which may improve their resilience to individual climactic events. Future competition between commercial cranberry farms and wild berries in protected areas could lead to conflicts between agriculture and conservation priorities. New varieties of commercial berries are required to maintain current commercial berry farms.

Vilardo, G., M. Faccoli, J. C. Corley, and M. V. Lantschner. 2022. Factors driving historic intercontinental invasions of European pine bark beetles. Biological Invasions 24: 2973–2991. https://doi.org/10.1007/s10530-022-02818-2

Largely assisted by global trade, alien insect species are being introduced into new territories at unprecedented rates. Among forest insects, pine bark beetles (Coleoptera: Curculionidae, Scolytinae) are a large and diverse group commonly recognized as successful invaders and important tree mortality agents in pine forests and commercial plantations. In this study, we collected information on the native and invaded distribution of 51 European bark beetles developing in Pinus species. We analyzed their invasion history in the Southern Hemisphere and the Americas and explored several factors that can help explain their invasion success: (1) propagule pressure: interception frequency in the non-native range(2) invasibility: potential establishment area based on climatic matching and host availability and (3) invasiveness: biological traits of the bark beetles ( i.e. , feeding habit, host range, body size, mating system, colonization behavior). We found that most (87%) of the introductions of the species to new regions occurred in the period 1960–2013, and that variables related with the three main factors were relevant in explaining invasion success. Propagule pressure was the factor that best explained bark beetle invasion probability, followed by invasibility of the novel area. In turn, biological attributes like mating system, body size and host range were also relevant, but showed a lower relative importance. Our study contributes to understand the main factors that explain forest insect invasion success. This information is critical for predicting future invasions to new regions and optimizing early-detection and biosecurity policies.

Reichgelt, T., D. R. Greenwood, S. Steinig, J. G. Conran, D. K. Hutchinson, D. J. Lunt, L. J. Scriven, and J. Zhu. 2022. Plant Proxy Evidence for High Rainfall and Productivity in the Eocene of Australia. Paleoceanography and Paleoclimatology 37. https://doi.org/10.1029/2022pa004418

During the early to middle Eocene, a mid‐to‐high latitudinal position and enhanced hydrological cycle in Australia would have contributed to a wetter and “greener” Australian continent where today arid to semi‐arid climates dominate. Here, we revisit 12 southern Australian plant megafossil sites from the early to middle Eocene to generate temperature, precipitation and seasonality paleoclimate estimates, net primary productivity (NPP) and vegetation type, based on paleobotanical proxies and compare to early Eocene global climate models. Temperature reconstructions are uniformly subtropical (mean annual, summer, and winter mean temperatures 19–21 °C, 25–27 °C and 14–16 °C, respectively), indicating that southern Australia was ∼5 °C warmer than today, despite a >20° poleward shift from its modern geographic location. Precipitation was less homogeneous than temperature, with mean annual precipitation of ∼60 cm over inland sites and >100 cm over coastal sites. Precipitation may have been seasonal with the driest month receiving 2–7× less than mean monthly precipitation. Proxy‐model comparison is favorable with an 1680 ppm CO2 concentration. However, individual proxy reconstructions can disagree with models as well as with each other. In particular, seasonality reconstructions have systemic offsets. NPP estimates were higher than modern, implying a more homogenously “green” southern Australia in the early to middle Eocene, when this part of Australia was at 48–64 °S, and larger carbon fluxes to and from the Australian biosphere. The most similar modern vegetation type is modern‐day eastern Australian subtropical forest, although distance from coast and latitude may have led to vegetation heterogeneity.