scholarly journals Pollen metabarcoding as a tool for tracking long-distance insect migrations

2018 ◽  
Author(s):  
Tomasz Suchan ◽  
Gerard Talavera ◽  
Llorenç Sáez ◽  
Michał Ronikier ◽  
Roger Vila

AbstractInsects account for the main fraction of Earth’s biodiversity and are key players for ecosystems, notably as pollinators. While insect migration is suspected to represent a natural phenomenon of major importance, remarkably little is known about it, except for a few flagship species. The reason for this situation is mainly due to technical limitations in the study of insect movement. Here we propose using metabarcoding of pollen carried by insects as a method for tracking their migrations. We developed a flexible and simple protocol allowing high multiplexing and not requiring DNA extraction, one of the most time consuming part of metabarcoding protocols, and apply this method to the study of the longdistance migration of the butterfly Vanessa cardui, an emerging model for insect migration. We collected 47 butterfly samples along the Mediterranean coast of Spain in spring and performed metabarcoding of pollen collected from their bodies to test for potential arrivals from the African continent. In total, we detected 157 plant species from 23 orders, most of which (82.8%) were insect-pollinated. African or African-Arabian endemic taxa contributed 21.0% of our dataset, strongly supporting the hypothesis that migratory butterflies colonize southern Europe from Africa in spring. Moreover, our data suggest that a northwards trans-Saharan migration in spring is plausible for early arrivals (February) into Europe, as shown by the presence of Saharan floristic elements. Our results demonstrate the possibility of regular insect-mediated transcontinental pollination, with potential implications for ecosystem functioning, agriculture and plant phylogeography. Despite current limitations, mostly regarding the availability of plant reference sequences and distribution data, the method proved to be useful and demonstrates great potential as plant genetic libraries and distribution datasets improve.

2016 ◽  
Vol 17 (3) ◽  
pp. 766 ◽  
Author(s):  
J. ARAGAY ◽  
D. VITALES ◽  
A. GÓMEZ GARRETA ◽  
M. A. RIBERA SIGUAN ◽  
F. STEEN ◽  
...  

Dictyota cyanoloma, a distinctive brown algal species characterized by a blue-iridescent margin, was recently reported as an introduced species in the Mediterranean Sea (Steen et al., 2016) but little is known about its distribution dynamics, morphological plasticity and genetic structure. In the present integrative study, we evaluate its past and present occurrence along the Mediterranean Iberian coast, assess the species’ phenology in Palamós (Girona, Spain) and analyze the haplotype diversity by sequencing 49 individuals from nine sampling sites for different chloroplast and mitochondrial DNA regions. Although D. cyanoloma currently occurs along the Mediterranean Iberian coast (in 19 of 36 localities sampled between Algeciras and Llançà, mostly in marinas and harbour environments), we were not able to find any herbarium material of this species (at BCN-Phyc and MA) predating the year 1987. In Palamós, D. cyanoloma is present all through the year, with a maximum development in winter and a minimum in summer. Fertile specimens are absent during summer (July and August). Sporophytes are dominant from January to June and dioecious gametophytes were found only in February, March and June. Information about the antheridia, which has never been described before, is provided. Two chloroplast and three mitochondrial haplotypes were observed, indicating that multiple introductions of D. cyanoloma occurred in the study area. Additionally, the genetic structure suggests that spread did not occur through simple advancing wave fronts but by several long-distance dispersal events. Further studies employing microsatellite markers could potentially offer a better resolution to unravel expansion and colonisation dynamics of D. cyanoloma in the Mediterranean Sea.


2018 ◽  
Vol 14 (12) ◽  
pp. 20180741 ◽  
Author(s):  
Michael T. Hallworth ◽  
Peter P. Marra ◽  
Kent P. McFarland ◽  
Sara Zahendra ◽  
Colin E. Studds

Insect migration is globally ubiquitous and can involve continental-scale movements and complex life histories. Apart from select species of migratory moths and butterflies, little is known about the structure of the annual cycle for migratory insects. Using stable-hydrogen isotope analysis of 852 wing samples from eight countries spanning 140 years, combined with 21 years of citizen science data, we determined the full annual cycle of a large migratory dragonfly, the common green darner ( Anax junius ). We demonstrate that darners undertake complex long-distance annual migrations governed largely by temperature that involve at least three generations. In spring, the first generation makes a long-distance northbound movement (further than 650 km) from southern to northern range limits, lays eggs and dies. A second generation emerges and returns south (further than 680 km), where they lay eggs and die. Finally, a third resident generation emerges, reproducing locally and giving rise to the cohort that migrates north the following spring. Since migration timing and nymph development are highly dependent on temperature, continued climate change could lead to fundamental changes in the biology for this and similar migratory insects.


BioScience ◽  
2010 ◽  
Vol 60 (5) ◽  
pp. 400-400 ◽  
Author(s):  
Cathy Lundmark

2021 ◽  
Vol 13 (18) ◽  
pp. 3744
Author(s):  
Linlin Fang ◽  
Weiming Tian ◽  
Rui Wang ◽  
Chao Zhou ◽  
Cheng Hu

Entomological radar is an effective means of monitoring insect migration, and can realize long-distance and large-scale rapid monitoring. The stable tracking of individual insect targets is the basic premise underlying the identification of insect species and the study of insect migration mechanisms. However, the complex motion trajectory and large number of false measurements decrease the performance of insect target tracking. In this paper, an insect target tracking algorithm in clutter was designed based on the multidimensional feature fusion strategy (ITT-MFF). Firstly, multiple feature parameters of measurements were fused to calculate the membership of measurements and target, thereby improving the data association accuracy in the presence of clutter. Secondly, a distance-correction factor was introduced to the probabilistic data association (PDA) algorithm to accomplish multi-target data association with a low computational cost. Finally, simulation scenarios with different target numbers and clutter densities were constructed to verify the effectiveness of the proposed method. The tracking result comparisons of the experimental data acquired from a Ku-band entomological radar also indicate that the proposed method can effectively reduce computational cost while maintaining high tracking precision, and is suitable for engineering implementation.


2016 ◽  
Vol 12 (10) ◽  
pp. 20160561 ◽  
Author(s):  
Constantí Stefanescu ◽  
David X. Soto ◽  
Gerard Talavera ◽  
Roger Vila ◽  
Keith A. Hobson

The painted lady, Vanessa cardui , is a migratory butterfly that performs an annual multi-generational migration between Europe and North Africa. Its seasonal appearance south of the Sahara in autumn is well known and has led to the suggestion that it results from extremely long migratory flights by European butterflies to seasonally exploit the Sahel and the tropical savannah. However, this possibility has remained unproven. Here, we analyse the isotopic composition of butterflies from seven European and seven African countries to provide new support for this hypothesis. Each individual was assigned a geographical natal origin, based on its wing stable hydrogen isotope (δ 2 H w ) value and a predicted δ 2 H w basemap for Europe and northern Africa. Natal assignments of autumn migrants collected south of the Sahara confirmed long-distance movements (of 4000 km or more) starting in Europe. Samples from Maghreb revealed a mixed origin of migrants, with most individuals with a European origin, but others having originated in the Sahel. Therefore, autumn movements are not only directed to northwestern Africa, but also include southward and northward flights across the Sahara. Through this remarkable behaviour, the productive but highly seasonal region south of the Sahara is incorporated into the migratory circuit of V. cardui .


2021 ◽  
Author(s):  
Rowan J Schley ◽  
Qin Ming ◽  
Mohammad Vatanparast ◽  
Panagotia Malakasi ◽  
Manuel de la Estrella ◽  
...  

Aim: Phenotypes which evolved for dispersal over ecological timescales may lead to significant macroevolutionary consequences, such as infrequent long-distance dispersal and diversification in novel environments. We aimed to reconstruct the phylogenetic history of Pterocarpus (Leguminosae/ Fabaceae) to assess whether seed dispersal phenotypes help to explain the current biogeographical patterns of this group. Location: Pantropical. Taxon: The Pterocarpus clade, particularly Pterocarpus (Leguminosae/Fabaceae). Methods: We sequenced ~300 nuclear loci captured using Angiosperms-353, a genomic 'bait set' for flowering plants, from which we generated a time-calibrated phylogenomic tree. To corroborate this, we also generated a time-calibrated phylogenetic tree from data-mined Sanger-sequencing data. We then collated distribution data and fruit dispersal morphology traits to compare trait-dependent and trait-independent biogeographical models, allowing us to assess whether dispersal traits influenced the spatio-temporal evolution of Pterocarpus. Finally, using the results of these model tests, we estimated the ancestral ranges and biomes of Pterocarpus species to better understand their biogeographical history. Results: We recovered well-supported phylogenetic relationships within Pterocarpus, within which there were two subclades - one Neotropical and the other Palaeotropical. Our divergence date estimates suggested that Pterocarpus largely diversified from around 12 Ma, during the Miocene. Trait-dependent biogeographical models were rejected for both range and biome evolution within Pterocarpus, but models parameterising dispersal were supported. Pterocarpus largely diversified in the Neotropics, followed by dispersal and diversification into Africa and Asia, with later dispersal into Australasia/Oceania. The neotropical subclade of Pterocarpus underwent multiple biome switches between moist forest and dry forest, while in palaeotropical Pterocarpus we reconstructed multiple switches between moist forest and grassland. Main conclusions: Overall, our analyses suggest that Pterocarpus underwent infrequent cross-continental dispersal and adaptation to novel biomes. While this was minimally impacted by fruit dispersal syndromes, shifts between moist and arid environments precipitated by long-distance dispersal and environmental change have played an important role in diversification within Pterocarpus since the Miocene.


2018 ◽  
Vol 96 (11) ◽  
pp. 1187-1195 ◽  
Author(s):  
Matthew D. Cameron ◽  
Kyle Joly ◽  
Greg A. Breed ◽  
Lincoln S. Parrett ◽  
Knut Kielland

Long-distance migrations by ungulate species are a globally imperiled natural phenomenon and conservation of them requires monitoring population vital rates. Satellite telemetry tracking is widely used for understanding the spatial distribution and movement of animals, especially migratory animals in remote environments. Recently, analytical methods have been developed to infer parturition events from movement data in multiple species that calve in isolation, but to date such methods have not been tested on animals that both migrate and spatially aggregate during calving. We applied two movement-based methods developed to infer parturition in nonmigratory woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) to 241 reproductive seasons spanning 6 years of GPS data from migratory barren-ground caribou (Rangifer tarandus granti J.A. Allen, 1902). We compared results from both methods to data from aerial surveys of collared females during the calving period. We found that each movement-based method had ∼80% overall accuracy to identify calving events, with interannual variation ranging from 61% to 100%. When we considered instances when the two analytical methods agreed on parturition outcome, the accuracy increased to 89% with an annual range of 73%–100%. Using these methods, we identified marked interannual differences in peak calving dates and higher parturition rates than previously reported for this caribou herd. The successful application of these analyses to a migratory, gregarious ungulate suggests a broader applicability of the methodology.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jenna Florio ◽  
Laura M. Verú ◽  
Adama Dao ◽  
Alpha S. Yaro ◽  
Moussa Diallo ◽  
...  

AbstractLong-distance migration of insects impacts food security, public health, and conservation–issues that are especially significant in Africa. Windborne migration is a key strategy enabling exploitation of ephemeral havens such as the Sahel, however, its knowledge remains sparse. In this first cross-season investigation (3 years) of the aerial fauna over Africa, we sampled insects flying 40–290 m above ground in Mali, using nets mounted on tethered helium-filled balloons. Nearly half a million insects were caught, representing at least 100 families from thirteen orders. Control nets confirmed that the insects were captured at altitude. Thirteen ecologically and phylogenetically diverse species were studied in detail. Migration of all species peaked during the wet season every year across localities, suggesting regular migrations. Species differed in flight altitude, seasonality, and associated weather conditions. All taxa exhibited frequent flights on southerly winds, accounting for the recolonization of the Sahel from southern source populations. “Return” southward movement occurred in most taxa. Estimates of the seasonal number of migrants per species crossing Mali at latitude 14°N were in the trillions, and the nightly distances traversed reached hundreds of kilometers. The magnitude and diversity of windborne insect migration highlight its importance and impacts on Sahelian and neighboring ecosystems.


2018 ◽  
Vol 151 (2) ◽  
pp. 194-208 ◽  
Author(s):  
Hatem A. Shabana ◽  
Teresa Navarro ◽  
Ali El-Keblawy

Background and aims – This study describes the dispersal traits of 302 species in five Afro-Arabian habitats from the hyper-arid hot desert of United Arabian Emirates (UAE).Methods – Diaspore size (diaspora length) was studied in relation to growth forms, dispersal modes, presence of structures for long distance dispersal, APG IV groups, phytogeography and dispersal phenology using ANOVA and Pearson χ2 test-statistical analyses.Results – Small diaspores were predominant (six orders of magnitude from 10-4 to 102). The major diaspores were found in Fabids phylogenetic APG IV group (1.80±0.41 cm) mainly trees and the minor in Commelinids (0.30±0.08 cm). The most dominant dispersal mode was semachory (43.7% of the total and 67.5% of the herbaceous species), followed by anemo-meteochory (28.8%) and barochory (23.8%). Semachores/barochores (67.5%) formed the largest groups from the Fabaceae, Poaceae, Boraginaceae, Brassicaceae and Amaranthaceae families. Savanna trees such as Acacia, Prosopis, Ziziphus sp. and Indigofera sp. produced large diaspores secondarily dispersed by vertebrates. Anemo-meteochoric species with small diaspores were predominantly semi-shrubs such as Haloxylon sp. Graminoids such as Stipa sp. and Stipagrostis sp., without structures for long-distance dispersal had diaspore appendages acted as “active drills” in soil cracks. Dryness (dry season) favours the efficient dispersion by the wind for the small shrub species with haired capsule (e.g. Aerva javanica), winged calyx (e.g. Astragalus squarrosus) or wings (e.g. Tribulus qatarensis). Most of the species studied (64.2%) dispersed in the dry season according to what was found in other arid region from the world. The longer dispersal phenology corresponded to Saharo-Arabian and Sudano-Decanian species which is related to the floristic richness of the study area. Species dispersal throughout the year indicates an important seed resource e.g. barochoric species with fleshy fruits or pods with nutrient structures (e.g. Senna italica and Indigofera sp.).Conclusions – In the hyper-arid hot desert of UAE, the dispersal spectra are close to those recorded in other arid environments but with particularities due to the presence of African floristic elements.


Author(s):  
James Cronshaw

Long distance transport in plants takes place in phloem tissue which has characteristic cells, the sieve elements. At maturity these cells have sieve areas in their end walls with specialized perforations. They are associated with companion cells, parenchyma cells, and in some species, with transfer cells. The protoplast of the functioning sieve element contains a high concentration of sugar, and consequently a high hydrostatic pressure, which makes it extremely difficult to fix mature sieve elements for electron microscopical observation without the formation of surge artifacts. Despite many structural studies which have attempted to prevent surge artifacts, several features of mature sieve elements, such as the distribution of P-protein and the nature of the contents of the sieve area pores, remain controversial.


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