scholarly journals Ecology and Genetic Structure of the Parasitoid Phobocampe confusa (Hymenoptera: Ichneumonidae) in Relation to Its Hosts, Aglais Species (Lepidoptera: Nymphalidae)

Insects ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 478
Author(s):  
Hélène Audusseau ◽  
Gaspard Baudrin ◽  
Mark R. Shaw ◽  
Naomi L. P. Keehnen ◽  
Reto Schmucki ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Latitudinal Gradient ◽  
Biotic Interactions ◽  
Climatic Conditions ◽  
Butterfly Species ◽  
Natural Ecosystems ◽  
Low Genetic Diversity ◽  
Key Species ◽  
Genomics Tools ◽  
Butterfly Larvae

The biology of parasitoids in natural ecosystems remains very poorly studied, though they are key species for their functioning. Here we focused on Phobocampe confusa, a Nymphalini specialist, responsible for high mortality rates in charismatic butterfly species in Europe (genus Aglais). We studied its ecology and genetic structure in connection with those of its host butterflies in Sweden. To this aim, we gathered data from 428 P. confusa individuals reared from 6094 butterfly larvae (of A. urticae, A. io, and in two occasions of Araschnia levana) collected over two years (2017 and 2018) and across 19 sites distributed along a 500 km latitudinal gradient. We found that P. confusa is widely distributed along the latitudinal gradient. Its distribution seems constrained over time by the phenology of its hosts. The large variation in climatic conditions between sampling years explains the decrease in phenological overlap between P. confusa and its hosts in 2018 and the 33.5% decrease in the number of butterfly larvae infected. At least in this study, P. confusa seems to favour A. urticae as host. While it parasitized nests of A. urticae and A. io equally, the proportion of larvae parasitized is significantly higher for A. urticae. At the landscape scale, P. confusa is almost exclusively found in vegetated open land and near deciduous forests, whereas artificial habitats are negatively correlated with the likelihood of a nest to be parasitized. The genetic analyses on 89 adult P. confusa and 87 adult A. urticae using CO1 and AFLP markers reveal a low genetic diversity in P. confusa and a lack of genetic structure in both species, at the scale of our sampling. Further genetic studies using high-resolution genomics tools will be required to better understand the population genetic structure of P. confusa, its biotic interactions with its hosts, and ultimately the stability and the functioning of natural ecosystems.

scholarly journals Ecology and population genetics of the parasitoid Phobocampe confusa (Hymenoptera: Ichneumonidae) in relation to its hosts, Aglais species (Lepidoptera: Numphalidae)

2020 ◽  
Author(s):  
Hélène Audusseau ◽  
Gaspard Baudrin ◽  
Mark R. Shaw ◽  
Naomi L.P. Keehnen ◽  
Reto Schmucki ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Latitudinal Gradient ◽  
Biotic Interactions ◽  
Climatic Conditions ◽  
Butterfly Species ◽  
Natural Ecosystems ◽  
Key Species ◽  
Butterfly Larvae

AbstractThe biology of parasitoids in natural ecosystems remain very poorly studied, while they are key species for their functioning. Here we focused on Phobocampe confusa, a vanessines specialist, responsible for high mortality rates in very emblematic butterfly species in Europe (genus Aglais). We studied its ecology and genetic structure in connection with those of its host butterflies in Sweden. To this aim, we gathered data from 428 P. confusa individuals reared from 6094 butterfly larvae (of A. urticae, A. io and in two occasions of Araschnia levana) collected over two years (2017 and 2018) and 19 sites distributed along a 500 km latitudinal gradient. We found that P. confusa is widely distributed along the latitudinal gradient. Its distribution is constrained over time by the phenology of its hosts. The large variation in climatic conditions between sampling years explains the decrease in phenological overlap between P. confusa and its hosts in 2018 and the 33.5% decrease in the number of butterfly larvae infected. At least in this study, P. confusa seems to favour A. urticae as host: while it parasitized nests of A. urticae and A. io equally, the proportion of larvae is significantly higher for A. urticae. At the landscape scale, P. confusa is almost exclusively found in vegetated open land and near deciduous forests, whereas artificial habitats are negatively correlated with the likelihood of a nest to be parasitized. The genetic analyses on 89 adult P. confusa and 87 adult A. urticae using COI and AFLP markers reveal a low genetic diversity in P. confusa and a lack of population genetic structure in both species, at the scale of our sampling. Further genetic studies using high-resolution genomics tools will be required to better understand the population genetic structure of P. confusa, its biotic interactions with its hosts, and ultimately the stability and the functioning of natural ecosystems.

scholarly journals Genetic diversity in clustered colonies of an Antarctic marine mesopredator: a role for habitat quality?

2021 ◽  
pp. 1-10
Author(s):  
Emiliano Mori ◽  
Claudia Brunetti ◽  
Antonio Carapelli ◽  
Lucia Burrini ◽  
Niccolò Fattorini ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Habitat Quality ◽  
Ross Sea ◽  
Molecular Genetic ◽  
Assignment Test ◽  
Pygoscelis Adeliae ◽  
Seabird Species ◽  
Low Genetic Diversity ◽  
Key Species

Abstract Genetic structure may be highly variable across seabird species, and particularly among those that are distributed over large geographical areas. The Adélie penguin (Pygoscelis adeliae) is a numerically dominant Antarctic seabird that is considered to be a key species in coastal ecosystems. Since the Last Glacial Maximum, penguin colonization of the Antarctic coastline occurred at varying geographical and temporal scales, contributing to an incomplete understanding of how modern colonies relate to each other at local or regional scales. We assessed the population genetic structure of Adélie penguins (n = 86 individuals) from three adjacent colonies along the Victoria Land coast using molecular genetic markers (i.e. seven microsatellite loci isolated through next-generation sequencing). Our results indicate meta-population dynamics and possibly relationships with habitat quality. A generally low genetic diversity (Nei's index: 0.322–0.667) was observed within each colony, in contrast to significant genetic heterogeneity among colonies (pairwise FST = 0.071–0.148), indicating that populations were genetically structured. Accordingly, an assignment test correctly placed individuals within the respective colonies from which they were sampled. The presence of inter-colony genetic differentiation contrasts with previous studies on this species that showed a lack of genetic structure, possibly due to higher juvenile or adult dispersal. Our sampled colonies were not panmictic and suggest a lower migration rate, which may reflect relatively stable environmental conditions in the Ross Sea compared to other regions of Antarctica, where the ocean climate is warming.

Landscape Change in the Steppe of Algeria South-West Using Remote Sensing

2018 ◽  
Vol 18 (1) ◽  
pp. 41-52
Author(s):  
Tayeb Sitayeb ◽  
Ishak Belabbes
Keyword(s):  
Remote Sensing ◽  
Social Systems ◽  
Bare Soil ◽  
Climatic Conditions ◽  
Landscape Dynamics ◽  
Landsat 8 ◽  
Natural Ecosystems ◽  
Stipa Tenacissima ◽  
Steppe Species ◽  
Sparse Vegetation

Abstract Landscape dynamics is the result of interactions between social systems and the environment, these systems evolving significantly over time. climatic conditions and biophysical phenomena are the main factors of landscape dynamics. Also, currently man is responsible for most changes affecting natural ecosystems. The objective of this work is to study the dynamics of a typical landscape of western Algeria in time and space, and to map the distribution of vegetation groups constitute the vegetation cover of this ecosystem. as well as using a method of monitoring the state of a fragile ecosystem by remote sensing to understand the processes of changes in this area. The steppe constitutes a large arid area, with little relief, covered with low and sparse vegetation. it lies between the annual isohyets of 100 to 400 mm, subjected to a very old human exploitation with an activity of extensive breeding of sheep, goats, and camels. Landsat satellite data were used to mapping vegetation groups in the Mecheria Steppe at a scale of 1: 300,000. Then, a comparison was made between the two maps obtained by a classification of Landsat-8 sensor Operational Land Imager (OLI) acquired on March 18, 2014, and Landsat-5 sensor Thematic Mapper (TM) acquired on April 25, 1987. The results obtained show the main changes affecting the natural distribution of steppe species, a strong change in land occupied by the Stipa tenacissima steppe with 65% of change, this steppe is replaced by Thymelaea microphylla, Salsola vermiculata, lygeum spartum and Peganum harmala steppe. an absence from the steppe Artemisia herba-alba that has also been replaced by the same previous steppes species. The groups with Quercus ilex and Juniperus phoenicea are characterized by a strong regression that was lost 60% of its global surface and transformed by steppe to stipa tenacissima and bare soil.

scholarly journals Identifying appropriate sampling and modelling approaches for analysing distributional patterns of Antarctic terrestrial arthropods along the Victoria Land latitudinal gradient

2010 ◽  
Vol 22 (6) ◽  
pp. 742-748 ◽  
Author(s):  
Tancredi Caruso ◽  
Ian D. Hogg ◽  
Roberto Bargagli
Keyword(s):  
Abiotic Factors ◽  
Relevant Literature ◽  
Biotic Interactions ◽  
Terrestrial Ecosystems ◽  
Climatic Conditions ◽  
Trophic Levels ◽  
Terrestrial Arthropods ◽  
Victoria Land ◽  
Dispersal Capability ◽  
Modelling Techniques

AbstractBiotic communities in Antarctic terrestrial ecosystems are relatively simple and often lack higher trophic levels (e.g. predators); thus, it is often assumed that species’ distributions are mainly affected by abiotic factors such as climatic conditions, which change with increasing latitude, altitude and/or distance from the coast. However, it is becoming increasingly apparent that factors other than geographical gradients affect the distribution of organisms with low dispersal capability such as the terrestrial arthropods. In Victoria Land (East Antarctica) the distribution of springtail (Collembola) and mite (Acari) species vary at scales that range from a few square centimetres to regional and continental. Different species show different scales of variation that relate to factors such as local geological and glaciological history, and biotic interactions, but only weakly with latitudinal/altitudinal gradients. Here, we review the relevant literature and outline more appropriate sampling designs as well as suitable modelling techniques (e.g. linear mixed models and eigenvector mapping), that will more adequately address and identify the range of factors responsible for the distribution of terrestrial arthropods in Antarctica.

Cryptic Lineages and a Population Dammed to Incipient Extinction? Insights into the Genetic Structure of a Mekong River Catfish

2019 ◽  
Vol 110 (5) ◽  
pp. 535-547 ◽  
Author(s):  
Amanda S Ackiss ◽  
Binh T Dang ◽  
Christopher E Bird ◽  
Ellen E Biesack ◽  
Phen Chheng ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Natural Populations ◽  
Principal Component ◽  
Flood Pulse ◽  
Mekong River ◽  
Effective Population ◽  
Long Distance ◽  
Genetic Lineages ◽  
Low Genetic Diversity ◽  
Population Size Estimates

Abstract An understanding of the genetic composition of populations across management boundaries is vital to developing successful strategies for sustaining biodiversity and food resources. This is especially important in ecosystems where habitat fragmentation has altered baseline patterns of gene flow, dividing natural populations into smaller subpopulations and increasing potential loss of genetic variation through genetic drift. River systems can be highly fragmented by dams built for flow regulation and hydropower. We used reduced-representation sequencing to examine genomic patterns in an exploited catfish, Hemibagrus spilopterus, in a hotspot of biodiversity and hydropower development—the Mekong River basin. Our results revealed the presence of 2 highly divergent coexisting genetic lineages which may be cryptic species. Within the lineage with the greatest sample sizes, pairwise FST values, principal component analysis, and a STRUCTURE analysis all suggest that long-distance migration is not common across the Lower Mekong Basin, even in areas where flood-pulse hydrology has limited genetic divergence. In tributaries, effective population size estimates were at least an order of magnitude lower than in the Mekong mainstream indicating these populations may be more vulnerable to perturbations such as human-induced fragmentation. Fish isolated upstream of several dams in one tributary exhibited particularly low genetic diversity, high amounts of relatedness, and a level of inbreeding (GIS = 0.51) that has been associated with inbreeding depression in other outcrossing species. Our results highlight the importance of assessing genetic structure and diversity in riverine fisheries populations across proposed dam development sites for the preservation of these critically important resources.

scholarly journals Challenges and Opportunities for Sustainable Management of Water Resources in the Island of Crete, Greece

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1538 ◽  
Author(s):  
V. A. Tzanakakis ◽  
A. N. Angelakis ◽  
N. V. Paranychianakis ◽  
Y. G. Dialynas ◽  
G. Tchobanoglous
Keyword(s):  
Water Management ◽  
Water Resources ◽  
Water Use ◽  
Water Availability ◽  
Water Sources ◽  
Climatic Conditions ◽  
Total Water ◽  
Natural Ecosystems ◽  
Treated Effluent ◽  
Critical Issues

Crete, located in the South Mediterranean Sea, is characterized by long coastal areas, varied terrain relief and geology, and great spatial and inter-annual variations in precipitation. Under average meteorological conditions, the island is water-sufficient (969 mm precipitation; theoretical water potential 3284 hm3; and total water use 610 hm3). Agriculture is by far the greatest user of water (78% of total water use), followed by domestic use (21%). Despite the high average water availability, water scarcity events commonly occur, particularly in the eastern-south part of the island, driven by local climatic conditions and seasonal or geographical mismatches between water availability and demand. Other critical issues in water management include the over-exploitation of groundwater, accounting for 93% of the water used in agriculture; low water use efficiencies in the farms; limited use of non-conventional water sources (effluent reuse); lack of modern frameworks of control and monitoring; and inadequate cooperation among stakeholders. These deficiencies impact adversely water use efficiency, deteriorate quality of water resources, increase competition for water and water pricing, and impair agriculture and environment. Moreover, the water-limited areas may display low adaptation potential to climate variability and face increased risks for the human-managed and natural ecosystems. The development of appropriate water governance frameworks that promote the development of integrated water management plans and allow concurrently flexibility to account for local differentiations in social-economic favors is urgently needed to achieve efficient water management and to improve the adaptation to the changing climatic conditions. Specific corrective actions may include use of alternative water sources (e.g., treated effluent and brackish water), implementation of efficient water use practices, re-formation of pricing policy, efficient control and monitoring, and investment in research and innovation to support the above actions. It is necessary to strengthen the links across stakeholders (e.g., farmers, enterprises, corporations, institutes, universities, agencies, and public authorities), along with an effective and updated governance framework to address the critical issues in water management, facilitate knowledge transfer, and promote the efficient use of non-conventional water resources.

scholarly journals A growing degree day inference model based on mountain birch leaf cuticle analysis over a latitudinal gradient in Fennoscandia

The Holocene ◽  
2019 ◽  
Vol 30 (2) ◽  
pp. 344-349
Author(s):  
Fabian EZ Ercan ◽  
Hugo Jan De Boer ◽  
Friederike Wagner-Cremer
Keyword(s):  
Latitudinal Gradient ◽  
Growing Season ◽  
Climatic Conditions ◽  
Mountain Birch ◽  
Habitat Conditions ◽  
Inference Model ◽  
Light Regimes ◽  
Latitudinal Transect ◽  
Dwarf Birch ◽  
Epidermis Cell

Cuticle analysis performed on fossil Betula nana (L.) leaves provides a strong proxy to reconstruct past growing season thermal properties expressed as growing degree days (GDD5). This proxy is so far available for the dwarf birch only and, therewith, restricted to regions or past periods of subarctic climatic conditions. In this study, we analysed modern leaf samples of mountain birch ( Betula pubescens spp. czerepanovii (N. I. Orlova) Hämet-Ahti), which has a wider temperature range than the dwarf birch B. nana. The strong latitudinal climate gradient over Fennoscandia provides a unique opportunity to track growing season temperature imprints in the epidermis cell morphology of the modern mountain birch. We quantified the GDD5-dependent epidermal cell expansion, expressed as the undulation index (UI), over a 10° latitudinal transect translating to a range from ~1500°C to ~600°C GDD5 in 2016. Our results indicate that even in mountain birch the UI is positively correlated to GDD5 and, moreover, is largely independent of regional habitat conditions such as daylight length and precipitation. These results imply that in addition to the earlier studied (sub-)arctic dwarf birch, the closely related mountain birch can also be utilized in GDD5 reconstructions. The abundant presence of fossil mountain birch leaves in sediments from warmer than (sub)arctic palaeoclimates enables the reconstruction of growing season climate dynamics over past phases of climate change, overcoming earlier restrictions of the proxy related to spatial and temporal species occurrence as well as local light regimes.

scholarly journals Migration of Sogatella furcifera between the Greater Mekong Subregion and northern China revealed by mtDNA and SNP

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Nan Yang ◽  
Zhaoke Dong ◽  
Aidong Chen ◽  
Yanqiong Yin ◽  
Xiangyong Li ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Mitochondrial Gene ◽  
Geographic Location ◽  
Northern China ◽  
Snp Markers ◽  
Shandong Province ◽  
Migration Route ◽  
Sogatella Furcifera ◽  
Low Genetic Diversity ◽  
Greater Mekong Subregion

Abstract Background The white-backed planthopper (WBPH), Sogatella furcifera (Horváth) (Hemiptera, Delphacidae), is a migratory pest of rice in Asia. Shandong Province, in northern China, is located on the migration pathway of WBPH between southern and northeast China. The potential sources of WBPH in northern China are poorly understood. We studied the sources of WBPH in Shandong Province by determining the population genetic structure of WBPH in 18 sites distributed in Shandong and in six regions of the Greater Mekong Subregion (GMS). We used mitochondrial gene and single-nucleotide polymorphism (SNP) markers for analysis. Results All of the WBPH populations studied in the seven regions had low genetic diversity. Pairwise FST values based on mtDNA ranged from − 0.061 to 0.285, while FST based on SNP data ranged from − 0.007 to 0.009. These two molecular markers revealed that 4.40% (mtDNA) and 0.19% (SNP) genetic variation could be explained by the interpopulation variation, while the rest came from intrapopulation variation. The populations in the seven geographic regions comprised four hypothetical genetic clusters (K = 4) not associated with geographic location. Eighty-four of 129 individuals distributed across the given area were designated as recent migrants or of admixed ancestry. Although the substantial migration presented, a weak but significant correlation between genetic and geographic distances was found (r = 0.083, P = 0.004). Conclusion The Greater Mekong Subregion was the main genetic source of WBPH in Shandong, while other source populations may also exist. The genetic structure of WBPH is shaped by both migration and geographic barriers. These results help clarify the migration route and the source of WBPH in northern China.

scholarly journals Pronounced genetic structure and low genetic diversity in European red-billed chough (Pyrrhocorax pyrrhocorax) populations

2012 ◽  
Vol 13 (5) ◽  
pp. 1213-1230 ◽  
Author(s):  
Marius A. Wenzel ◽  
Lucy M. I. Webster ◽  
Guillermo Blanco ◽  
Malcolm D. Burgess ◽  
Christian Kerbiriou ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Low Genetic Diversity
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