scholarly journals MEDITERATRI project - assessing the trophic ecology of predatory arthropods in Mediterranean agriculture via DNA metabarcoding diet analyses

2019 ◽  
Vol 2 ◽  
Author(s):  
Lucija Šerić Jelaska ◽  
Barbara Anđelić ◽  
Mišel Jelić ◽  
Tomislav Kos

A type of management and the use of pesticides in arable land may negatively affect a range of soil biota and thus their food webs important for ecosystem functioning. By analysing trophic interactions we could reveal the extent of potential benefits that certain organisms can provide in biocontrol and maintaining healthy ecosystems. To evaluate the role of predatory arthropods within olive orchards and vineyards under Integrated Pest Management (IPM) and Ecological Pest Management (EPM) we collected carabid beetles together with other dominant predatory arthropods in the field (e.g. ladybugs, antlions, spiders, centipedes) and subdued the individuals to molecular gut content analyses using NGS. DNA metabarcoding diet analysis approach allowed detecting a wide variety of taxa from gut contents of the predators. In addition, using ICP-MS and LC-MS/MS we quantified Cu, pesticides and its residues in soil and animals representing different trophic guilds. Since concentrations of some toxic compounds detected in carabids body were negatively correlated with those in the soil, we aim to identify a potential vector for possible transfer of toxicants to general predators via predation. The results contribute to the risk assessment of proliferation of detected chemical compounds including copper in the ecosystem and to the knowledge on the overall field sustainability of predatory invertebrates to maximize their role in pest control. The study was conducted under the project activity of HRZZ – Mediteratri.

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Eneko Bachiller ◽  
Marta Albo-Puigserver ◽  
Joan Giménez ◽  
Maria Grazia Pennino ◽  
Neus Marí-Mena ◽  
...  

Abstract This work combines state-of-the-art methods (DNA metabarcoding) with classic approaches (visual stomach content characterization and stable isotope analyses of nitrogen (δ15N) and carbon (δ13C)) to investigate the trophic ecology of anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) at high taxonomic and spatial resolution in the Western Mediterranean Sea. Gut contents observed are in accordance with the dietary plasticity generally described for anchovy and sardine, suggesting a diet related to the opportunistic ingestion of available prey in a certain area and/or time. Genetic tools also showed modest inter-specific differences regarding ingested species. However, inter-specific and intra-specific differences in ingested prey frequencies and prey biomass reflected a latitudinal signal that could indicate a more effective predation on large prey like krill by anchovy versus sardine, as well as a generalized higher large prey ingestion by both species southwards. In fact, both species presented lower δ15N in the northernmost area. This latitudinal gradient indicates changes in the trophic ecology of anchovy and sardine that coincide with previously described better biological conditions for fish in the southern part of the study area as well as higher landings of both species in recent years.


Author(s):  
Pierre Taberlet ◽  
Aurélie Bonin ◽  
Lucie Zinger ◽  
Eric Coissac

Chapter 17 “Diet analysis” focuses on the specificities of DNA metabarcoding in the context of diet analyses. It presents the proof-of-concept study, which examined the diet of several herbivore species using next-generation sequencing for the first time. Chapter 17 reports how DNA-based analysis of bison diet helped evaluate the effect of conservation policies in a protected area. The different strategies aiming at disentangling predator and prey sequences in carnivorous diets are reviewed, including the use of a blocking oligonucleotide. Using bear diet as a study case, the issues associated with omnivorous diets are discussed, particularly that of integrating several diet components. Finally, Chapter 17 develops several important methodological and experimental factors to consider in eDNA-based diet analyses. These comprise the source of eDNA, the quantitative aspects, and the use of diet as a proxy of surrounding biodiversity (e.g., as in the case of invertebrate samplers).


2018 ◽  
Author(s):  
Stefaniya Kamenova ◽  
Vincent Bretagnolle ◽  
Manuel Plantegenest ◽  
Elsa Canard

AbstractMaximizing the delivery of key ecosystem services such as biological control through the management of natural enemy communities is one of the major challenges for modern agriculture. The main obstacle lies in our yet limited capacity of identifying the factors that drive the dynamics of trophic interactions within multi-species assemblages. Invertebrate generalist predators like carabid beetles are known for their dynamic feeding behaviour. Yet, at what extent different carabid species contribute to the regulation of animal and plant pests within agroecosystems is currently unknown. Here, we developed a DNA metabarcoding approach for characterizing the full diet spectrum of a community of fourteen very common carabid species inhabiting an intensively managed Western-European agroecosystem. We then investigated how diet and biological control potential within the carabid community varies with the sampling field location and the crop type (wheat vs oilseed rape). DNA metabarcoding diet analysis allowed to detect a wide variety of animal and plant taxa from carabid gut contents thus confirming their generalist feeding behaviour. The most common prey categories detected were arachnids, insects, earthworms and several plant families potentially including many weed species. Our results also show that the field location and the crop type are much stronger determinants then the species regarding carabid dietary choice: significantly more trophic links involving dipteran prey were observed in wheat, whereas more collembolan and plant prey was consumed in oilseed rape by the same carabid community. We speculate that structural differences in the habitats provided by these two crop types drive differences in resource availability cascading up the trophic chain, and we assume that specific carabid taxa could hardly be used to infer levels of ecosystem services (biological control) or disservices (e.g. intraguild predation). However, as this is the first study to report the use of DNA metabarcoding diet analysis in predatory carabid beetles we urge caution over the interpretation of our results. For instance, overall detection rates were rather low (31% of the individuals analysed tested positive for at least one prey category) most likely due to the overwhelming amplification of the carabid host DNA. Therefore, we acknowledge that more studies are required in order to confirm our observations and conclude with few recommendations for further improvements of the community-level DNA metabarcoding analysis of carabid diet.


2021 ◽  
Author(s):  
Matthew Howse

<p><b>Social wasps are considered among the most successful and impactful invasive species in the world. One species, Polistes dominula has spread from its native Mediterranean range to every continent except Antarctica. This wasp reached New Zealand in the last decade where it has established in the north of the South Island, however, reports of its presence are increasing throughout the country. Due to its recent arrival in New Zealand, little is known about where this species is likely to establish or what impacts it may have on local insect communities. In this thesis, I conducted two studies to investigate these questions, providing valuable information that may inform future management of this invasive species. </b></p><p>In chapter 2, I used two bioclimatic modelling methods to predict areas of suitable habitat across four regions in the southern hemisphere. These models were informed by global temperature and precipitation data as well as global distribution occurrence data of P. dominula. These data were used to estimate conditions most highly correlated with the presence of this wasp. The models identified large areas across the target regions that were climatically suitable for the establishment of P. dominula. Many of these areas are not known to currently contain populations of this species, representing habitat potentially vulnerable to further invasion by P. dominula. Areas across South America, South Africa and Australia were predicted to be climatically suitable. In New Zealand, much of the North Island and eastern parts of the South Island were predicted to be suitable habitat for this wasp. These results suggest that P. dominula could potentially establish across more of the country and expand its invaded range. Information provided by these models may guide conservation and biosecurity management by highlighting key areas where prevention and mitigation should be prioritized. </p><p>In chapter 3, I used molecular diet analysis to investigate the range of prey being utilised by P. dominula in New Zealand. Using DNA barcoding, larval gut contents of P. dominula and another closely related species, Polistes chinensis, were analysed to identify what species were present in the diet of both wasps. Butterflies and moths (Lepidoptera) were found to be the most highly represented order in both species’ diets. True bugs (Hemiptera) and flies (Diptera) were also abundant. Both wasps were shown to consume a range of native and introduced species including a number of agricultural pests. P. dominula was found to utilise a wider range of prey than P. chinensis. This more diverse prey range, combined with known differences in nesting behaviour, suggest that P. dominula may represent a more significant threat to invertebrate diversity than the already well-established P. chinensis. These results may inform conservation and biosecurity managers on which species are most at risk where this new invasive wasp becomes established. </p><p>This thesis provides insights into the potential impacts of a new invasive species to New Zealand. Both chapters represent the first time that these methods have been used to study P. dominula. This work highlights the need for continued monitoring of wasp populations throughout New Zealand, especially in regions highlighted as vulnerable to P. dominula establishment. We also suggest the need to prioritise the conservation of ‘at-risk’ species in coastal and human-altered habitats. Increased public engagement through the citizen-science initiatives should be encouraged while more research into management and control methods is recommended.</p>


2021 ◽  
Author(s):  
Li-Lin Chen ◽  
Gabor Pozsgai ◽  
Xiang-Yu Li ◽  
Lei Li ◽  
Gadi V.P. Reddy ◽  
...  

AbstractBeetles are visible members of food webs in tea plantations, with high species richness and abundance. Many tea pests, as well as natural enemies, are members of this order, so a knowledge of how groundcovers affect beetles can aid pest management. We collected beetles in a replicated field experiment in the Wuyi Mountains, Fujian Province China. Tea was intercropped with Paspalum notatum or Chamaecrista rotundifolia, or rows were cleared to bare ground, or in the control they were left unmanaged to allow weeds to grow naturally. Sampling, done by sweep netting and vegetation beating, was conducted monthly, between May 2006 and April 2008, and Coleoptera abundance, biomass, species richness and assemblage structures were compared between groundcover treatments. Total beetle abundance and species richness were significantly higher in tea intercropped with C. rotundifolia and bare ground than in naturally grown weedy control. Whilst there was no difference between predator assemblages among treatments for any measure, herbivores were more abundant, weighed more, and were more diverse in C. rotundifolia treatments than in weedy control. Biomass and species richness were also greater in plots with P. notatum groundcover than those in weedy control. We found that beetle assemblages varied both seasonally and with ground cover treatment, but the potential pest control impact of more species-rich beetle assemblages was mixed, and further work is needed to gain information on trophic groups with potential benefits for use in non-insecticidal pest management.


2014 ◽  
Vol 111 (5) ◽  
pp. 631-638 ◽  
Author(s):  
Lucija SERIC JELASKA ◽  
Damjan FRANJEVIC ◽  
Sven D. JELASKA ◽  
William O.C. SYMONDSON

Symmetry ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1890
Author(s):  
Lara Ivanković Tatalović ◽  
Barbara Anđelić ◽  
Mišel Jelić ◽  
Tomislav Kos ◽  
Hugo A. Benítez ◽  
...  

Fluctuating asymmetry (FA) is used in assessing the effect of environmental stress on the development stability of individuals by measuring small random deviations from perfect bilateral symmetry. Here, we checked for FA on two predatory carabid beetles, Pterostichus melas and Poecilus koyi, in order to evaluate species response to agricultural practices within Mediterranean agroecosystems, as well as FA as a method. The samples were collected in vineyards and olive groves, both under integrated pest management (IPM) and ecological pest management (EPM), and in pristine habitats in the Mediterranean region of Croatia. Geometric morphometrics (GMMs) were used to analyze the pronotum and abdomen shape variations and left–right asymmetries of each population. In respect to the FA measurements, analyzed species responded differently, with P. koyi displaying a lower intensity of FA than P. melas. On the other hand, P. melas beetles from vineyards showed a higher intensity of FA compared with populations from pristine habitats and olive groves. Accordingly, FA pointed out olive groves as potentially less adverse habitats to predatory carabids, keeping in mind the different levels of asymmetry between the two species. Our study singled out P.melas as a more suitable species for further research, in the effect that different agricultural practices can have their impact on non-target invertebrates analyzed by measuring the FA.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Andreas Ravache ◽  
Karen Bourgeois ◽  
Henri Weimerskirch ◽  
Angélique Pagenaud ◽  
Sophie de Grissac ◽  
...  

Abstract Two species breeding in sympatry are more likely to coexist if their ecological niches are segregated either in time, space or in trophic habits. Here, we combined GPS-tracking, stable isotope analysis and DNA metabarcoding analysis to understand how the rare Tahiti petrel Pseudobulweria rostrata (TP) copes with the very abundant (i.e. 500,000 breeding pairs) wedge-tailed shearwater Ardenna pacifica (WTS) when breeding in sympatry in a tropical area. WTS foraged in restricted areas along their path, while TP predominantly foraged using extensive search behavior, suggesting a more opportunistic foraging strategy. Interspecific overlap of foraging areas was higher than intraspecific overlap. Breeding seasons largely overlap between species during the study, but TP seems to be asynchronous breeders. TP fed upon prey with higher δ15N values than WTS, and their diet was mainly composed of deep-sea organisms. TP could feed upon dead prey floating at the surface while WTS preyed mainly upon fish species that generally move in schools. Our study highlights several segregating mechanisms (temporal, behavioral and trophic) that could facilitate the coexistence of the two species despite the predominant number of WTS, and provides the very first information on the foraging and trophic ecology of the poorly-known TP.


2020 ◽  
Vol 32 (6) ◽  
pp. 496-507
Author(s):  
Loïc N. Michel ◽  
Fabienne L. Nyssen ◽  
Patrick Dauby ◽  
Marie Verheye

AbstractIn Antarctica, amphipods form a highly diverse group, occupy many different ecological niches and hold an important place in food webs. Here, we aimed to test whether differences in Antarctic amphipod feeding habits were reflected in their mandible morphology, and if mouthpart specialization could be used to describe amphipod trophic ecology. To do so, we compared mandible morphology in nine species spanning seven families and five functional groups (grazers, suspension feeders, generalist predators, specialist predators and scavengers). Mandible morphology adequately depicted some aspects of amphipod trophic ecology, such as the trophic level at which animals feed or their degree of dietary specialization. On the other hand, links between mandible morphology and amphipod diet were seldom unambiguous or straightforward. Similar adaptations were found in distinct functional groups. Conversely, mandible morphology could vary within a single functional group, and phylogenetic effects sometimes complicated the interpretation of form-function relationships. Overall, mandible morphology on its own was generally not sufficient to precisely predict amphipod feeding strategies. However, when combined with other methods (e.g. gut contents, trophic markers), it constitutes a valuable source of information for integrative studies of amphipod ecological diversity in the Southern Ocean.


2015 ◽  
Vol 20 (3) ◽  
pp. 170 ◽  
Author(s):  
Ahmad Zahid ◽  
M.F. Rahardjo ◽  
Lenny S Syafei ◽  
Rini Susilowati

Pengetahuan mengenai ekologi trofik merupakan dasar dalam memahami ekosistem secara keseluruhan yang dapat dijelaskan melalui pola hubungan trofik interspesies ataupun interserikat. Penelitian bertujuan untuk menjelaskan ekologi trofik meliputi indeks trofik dan jenis makanan dominan, serikat dan tingkat trofik, dan variasi spasial dan temporal komunitas ikan di estuari Segara Menyan. Pengambilan ikan contoh dilakukan setiap bulan pada zona berbeda. Ikan contoh dipisahkan berdasarkan waktu dan lokasi pengamatan, dianalisis isi saluran pencernaannya. Analisa data meliputi indeks vakuitas, jumlah total organisme makanan, jenis makanan dominan, luas relung makanan, dan tingkat trofik.  Pada pengamatan 106 spesies ikan, sebanyak 1-380 saluran pencernaan ikan diamati. Sebanyak lima dari 106 spesies memiliki nilai indeks vakuitas “0” dan jumlah makanan yang dikonsumsi bervariasi mulai dari empat hingga 27 jenis makanan. Secara umum, luas relung ikan adalah rendah berkisar 0,20-0,78 dan kebanyakan berada pada kisaran 0,20-0,48. Zooplankton merupakan jenis makanan paling dominan dikonsumsi oleh ikan. Komunitas ikan dikelompokkan dalam tujuh serikat trofik, yaitu detritivora, fitoplanktivora, zooplanktivora, zoobentivora, moluskivora, krustasivora, dan pisivora. Tingkat trofik komunitas ikan berkisar 2,05-4,73. Faktor perubahan ontogenetik, persediaan makanan, karakteristik habitat, dan ruaya beberapa spesies ikan memengaruhi variasi spasio-temporal jejaring makanan di Segara Menyan. Kata kunci: interaksi trofik, laguna, ikan, variasi spasio-temporal, serikat trofik Knowledge of trophic ecology is one way to understanding the whole ecosystem which explained by trophic relationship pattern (interspecies or interguild). The objective research was described of the trophic ecology, i.e. trophic index and dominant prey, trophic guild and trophic level, and spatio-temporal variation of fish community in Segara Menyan coastal lagoon. Fish were collected monthly for one year at three zones. Fish samples were placed in separate labelled plastic bags according to the time scale and location sampling, then gut contents were analyzed. The data of vacuity index, number of prey, prey dominant, diet breadth, and trophic level were analyzed. For each of 106 fish species, between 1 and 380 stomachs, were examined. The vacuity index was also different among species. Five of 106 species had a vacuity index of “0” and total number of food items consumed varied between fish species, ranging from three items to 27 items. The overall diet breadth (Bi) was relatively low among species, ranging from 0.20 to 0.78, with most of them between 0.20 and 0.48. Calanoid copepods comprised the most common food item consumed by all the fishes examined. Fishes occurring can be broadly categorized into seven different trophic guilds. The trophic level of fish communities ranged from 2.05 to 4.73. Spatio-temporal variation of food web was influenced of ontogenetic shift, food availability, habitat characteristic, and migration of some species in Segara Menyan coastal lagoon. Keywords: trophic interaction, lagoon, fishes, spatio-temporal variation, trophic guild


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