Swedish Museum of Natural History
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The potential of the solitary parasitoid Microctonus brassicae for the biological control of the adult cabbage stem flea beetle, Psylliodes chrysocephala
No full textThe cabbage stem flea beetle (CSFB), Psylliodes chrysocephala L. (Coleoptera: Chrysomelidae), is a major pest of oilseed rape, Brassica napus L. (Brassicaceae), within the UK and continental Europe. Following the withdrawal of many broad-spectrum pesticides, most importantly neonicotinoids, and with increased incidence of pyrethroid resistance, few chemical control options remain, resulting in the need for alternative pest management strategies. We identified the parasitoid wasp Microctonus brassicae (Haeselbarth) (Hymenoptera: Braconidae) within CSFB collected from three independent sites in Norfolk, UK. Parasitism of adult CSFB was confirmed, and wasp oviposition behaviour was described. Moreover, we show that within captive colonies parasitism rates are sufficient to generate significant biological control of CSFB populations. A sequence of the M. brassicae mitochondrial cytochrome oxidase 1 (MT-CO1) gene was generated for rapid future identification. Moroccan specimens of Microctonus aethiopoides (Loan), possessing 90% sequence similarity, were the closest identified sequenced species. This study represents the first description published in English of this parasitoid of the adult cabbage stem flea beetle
Description of a new marine predatory nematode Latronema dyngi sp. nov. (Nematoda, Chromadorida, Selachinematidae) from the west coast of Sweden and an updated phylogeny of Chromadoria
No full textA new nematode species, Latronema dyngi sp. nov., is described from Skagerrak off the west coast of Sweden with the type locality near Dyngö island. Latronema dyngi sp. nov. is characterized by multispiral amphideal fovea with circular outline, 0.2– 0.3 corresponding body diameters wide in males and 0.1–0.2 corresponding body diameters wide in females, 12 cuticular longitudinal ridges and 18–27 precloacal supplements in males. Latronema dyngi sp. nov. most closely resembles L. orcinum in terms of body length; demanian ratios a, b, c and c′; number of amphid turns in males; and the ratio of spicule length to cloacal body diameter. The two species can be differentiated by the number longitudinal ridges on the cuticle (12 for Latronema dyngi sp. nov. vs 20–22 for L. orcinum) and spicule length (65–78 μm for L. dyngi vs 60 for L. orcinum) and shape (weakly arcuate for L. dyngi sp. nov. vs strongly arcuate for L. orcinum). We also performed a maximum likelihood phylogenetic analysis on over 250 nematodes of the subclass Chromadoria based on their nearly full-length 18S rDNA sequences. In agreement with previous studies, our analysis supported Selachinematidae as a monophyletic group and placed Richtersia Steiner, 1916 within Desmodoridae Filipjev, 1922 or just outside of the main Desmodorida clade with the latter placement not well supported.Systematics of poorly known marine nematodes of the class Chromadorea from SwedenSystematics of Swedish free-living nematodes of the orders Desmodorida and Araeolaimid
Shell structure, ornamentation and affinity of the problematic early Cambrian brachiopod Heliomedusa orienta
No full textThe origin of the Brachiopoda has long been a hotly debated topic, and various models have been proposed following the latest finds of exceptionally preserved material. The lower Cambrian (Stage 3) Heliomedusa orienta from the Chengjiang Konservat‐Lagerstätte, eastern Yunnan of South China, is an important example of exceptional preservation. A wide variety of affinities have been proposed for Heliomedusa, but recently it has been suggested to reside within the mickwitziids, which may form a stem group to the Brachiopoda. Detailed studies of exceptionally preserved Heliomedusa have increased our knowledge of the soft‐part anatomy of this important early brachiopod, but unfortunately, almost nothing is known about its shell structure. Here, we describe new exceptionally preserved specimens from the Chengjiang biota to better reveal both shell structure and ornamentation. Its reticulate–pustulose ornament and tubular structure are reminiscent of traits seen in other mickwitziid brachiopods. In addition, two types of setae can be observed. Apart from the pyritized marginal mantle setae, some tubules are filled with iron oxides, potentially representing thinner and shorter penetrative setae. Both valves of H. orienta appear to have been less mineralized as compared to Mickwitzia monilifera, and the two species differ in diameter and density of tubules and pustules, and in terms of slightly less projected profile of ventral valve with lower umbo posteromedially placed. Although Heliomedusa clearly is closely related to Mickwitzia, their different preservational modes (compacted poorly mineralized/noncompacted mineralized) make detailed comparison difficult; they are provisionally kept as separate genera pending further studies of better‐preserved Chinese material
Early Cambrian organophosphatic brachiopods from the Xinji Formation, at Shuiyu section, Shanxi Province, North China
No full textAbundant and diverse small shelly fossils have been reported from Cambrian Series 2 in North China, but the co-occurring brachiopods are still poorly known. Herein, we describe seven genera, five species and two undetermined species of organophosphatic brachiopods including one new genus and new species from the lower Cambrian Xinji Formation at Shuiyu section, located on the southern margin of North China Platform. The brachiopod assemblage comprises one mickwitziid (stem group brachiopoda), Paramickwitzia boreussinaensis n. gen. n. sp., a paterinide, Askepasma toddense Laurie, 1986, an acrotretoid, Eohadrotreta cf. zhenbaensis Li and Holmer, 2004, a botsfordiid, Schizopholis yorkensis (Holmer and Ushatinskaya in Gravestock et al., 2001) and three linguloids, Spinobolus sp., Eodicellomus cf. elkaniiformis Holmer and Ushatinskaya in Gravestock et al., 2001 and Eoobolus sp. This brachiopod assemblage suggests a late Age 3 to early Age 4 for the Xinji Formation and reveals a remarkably strong connection with coeval faunas from East Gondwana, particularly the Hawker Group in South Australia. The high degree of similarity (even at species level) further supports a close palaeogeographic position between the North China Platform and Australian East Gondwana during the early Cambrian as indicated by small shelly fossil data
Cecilia Andersson : Entomolog, pionjär, globetrotter
No full textCecilia Anderson var pionjär som kvinnlig entomolog och resenär. Hon kan räknas som den första kvinnan i Sverige som var aktiv insektssamlare på global nivå med en egenhändigt insamlad och vetenskapligt etiketterad samling.History of Entomolog
Unroll Please : Deciphering the Genetic Code in Scrolls and Other Ancient Materials
No full textThe unrelenting development of ancient DNA methods now allows researchers to obtain archaeogenetic data from increasingly diverse sources. In a new study in this issue of Cell, researchers apply the latest DNA technologies to unravel the mysteries of the Dead Sea Scrolls, one of the world’s most famous and influential sets of ancient parchments
Variation in skull bone mineral density of ringed seals (Phoca hispida) from the Gulf of Bothnia and West Greenland between 1829 and 2019
No full textBone is remodelled constantly through a balance of bone formation and resorption. This process can be affectedby various factors such as hormones, vitamins, nutrients and environmental factors, which can create an imbalanceresulting in systemic or local bone alteration. The aim of the present study was to analyse the changes in bone mineral density (BMD) over time in skulls of ringed seals (Pusa hispida) from the Baltic and Greenland using museum samples. Overall, 303 skulls (102 Male, 89 Female, 112 unknown) were used for bone investigationsand were divided into three periods according to collection year: before 1958 (n = 167), between 1958 and 1989 (n=40) and after 1994 up to 2019 (n=96). All skulls were examined by dual-energy X-ray absorptiometryto obtain the BMD. Skull BMD of the Baltic seals was positively correlated with the historical polychlorinatedbiphenyls (PCB) contamination having potential effects on the constitution of bones. BMD fluctuated between the three study periods (LM: p-value < 0.001, F-value = 47.5) with the lowest BMD found between 1897 and 1957, in the Gulf of Bothnia, where the highest peak of contaminant concentration was in the second period. BMD levels increased with increasing PCB concentration (LM: p < 0.001). The Greenland population showed significant lower BMD levels in the pollution and post-pollution period than the Baltic population (LM:p < 0.001). It also revealed a higher BMD in males than in females (LM: p=0.03). In conclusion, the variations between 1829 and 2019 in the Baltic Sea and Greenland may to a certain extent reflect normal fluctuations; however, this study revealed several factors affecting BMD, including sex and PCB levels
Messinian vegetation and climate of the intermontane Florina–Ptolemais–Servia Basin, NW Greece inferred from palaeobotanical data: how well do plant fossils reflect past environments?
No full textThe late Miocene is marked by pronounced environmentalchanges and the appearance of strong temperature andprecipitation seasonality. Although environmental heterogeneityis to be expected during this time, it is challenging to reconstructpalaeoenvironments using plant fossils. We investigated leavesand dispersed spores/pollen from 6.4 to 6 Ma strata inthe intermontane Florina–Ptolemais–Servia Basin (FPS) ofnorthwestern Greece. To assess how well plant fossils reflectthe actual vegetation of the FPS, we assigned fossil taxa tobiomes providing a measure for environmental heterogeneity.Additionally, the palynological assemblage was compared withpollen spectra from modern lake sediments to assess biases inspore/pollen representation in the pollen record. We found aclose match of the Vegora assemblage with modern Fagus–Abiesforests of Turkey. Using taxonomic affinities of leaf fossils, wefurther established close similarities of the Vegora assemblage with modern laurophyllous oak forests of Afghanistan. Finally, using information from sedimentaryenvironment and taphonomy, we distinguished local and distantly growing vegetation types.We thensubjected the plant assemblage of Vegora to different methods of climate reconstruction and discussedtheir potentials and limitations. Leaf and spore/pollen records allow accurate reconstructions ofpalaeoenvironments in the FPS, whereas extra-regional vegetation from coastal lowlands isprobably not captured
Brain expansion in early hominins predicts carnivore extinctions in East Africa
No full textWhile the anthropogenic impact on ecosystems today is evident, it remains unclear if the detrimental effect of hominins on co-occurring biodiversity is a recent phenomenon or has also been the pattern for earlier hominin species. We test this using the East African carnivore fossil record. We analyse the diversity of carnivores over the last four million years and investigate whether any decline is related to an increase in hominin cognitive capacity, vegetation changes or climatic changes. We find that extinction rates in large carnivores correlate with increased hominin brain size and with vegetation changes, but not with precipitation or temperature changes. While temporal analyses cannot distinguish between the effects of vegetation changes and hominins, we show through spatial analyses of contemporary carnivores in Africa that only hominin causation is plausible. Our results suggest that substantial anthropogenic influence on biodiversity started millions of years earlier than currently assumed