Diapause expression in a Québec, Canada population of the parasitoidAphidius ervi(Hymenoptera: Braconidae)

2019 ◽  
Vol 151 (3) ◽  
pp. 345-349 ◽  
Author(s):  
Kévin Tougeron ◽  
Joan van Baaren ◽  
Cécile Le Lann ◽  
Jacques Brodeur
Keyword(s):  
Climate Change ◽  
Aphidius Ervi ◽  
Agricultural Pests ◽  
Plastic Response ◽  
Parasitoid Species ◽  
Genetic Changes ◽  
Mild Winter ◽  
Two Temperatures ◽  
Set Up ◽  
Diapause Incidence

AbstractAphidius erviHaliday (Hymenoptera: Braconidae) is a major natural enemy of several agricultural pests in North America. Yet little is known about its overwintering strategy, especially concerning the plastic response to photoperiod and temperature that induce diapause. Information on parasitoid overwintering patterns is of great importance if we aim to predict their phenology and better inform pest outbreak control. Moreover, there is increasing evidence of plastic and genetic changes in overwintering strategies in insect from temperate areas following climate change. We set up a laboratory approach to better understand the factors acting on diapause induction inA. ervi. We studied the diapause incidence in a population from Québec, Canada, using the combination of two temperatures (14 °C and 20 °C) and three photoperiod treatments (10:14, 12:12, 14:10 [light:dark] hours). We found an effect of both factors on diapause incidence;A. erviexpressed close to 95% of diapause at the most fall-like conditions (14 °C, 10:14 [light:dark] hours) and almost no diapause (3.5%) at the most summer-like conditions tested (20 °C, 14:10 [light:dark] hours). This parasitoid species does have the potential to enter diapause in Québec before lethal frosts, despite a recent introduction from France (1960s), where mild winter occurs compared with Québec.

scholarly journals Effect of diapause on cold-resistance in different life-stages of an aphid parasitoid wasp

2018 ◽  
Author(s):  
Kevin Tougeron ◽  
Leslie Blanchet ◽  
Joan van Baaren ◽  
Cecile Le Lann ◽  
Jacques Brodeur
Keyword(s):  
Cold Resistance ◽  
Cost Benefit ◽  
Parasitoid Wasp ◽  
Aphidius Ervi ◽  
Life Stages ◽  
Aphid Parasitoid ◽  
Trade Off ◽  
Mild Winter ◽  
First Case ◽  
Diapause Incidence

To overwinter, insects from mild temperate areas can either enter diapause or remain active. Both strategies involve costs and benefits depending on the environment. In the first case, the emerging individuals will resist winter but have a reduced fitness because diapause entails physiological and ecological costs. In the second case, individuals need to be cold-resistant enough to withstand winter temperatures during their immature and adult stages, but could avoid diapause-associated costs. In mild temperate areas, the cost-benefit balance between the diapause and the non-diapause strategy would likely change in response to climate warming. A trade-off between these two strategies should lead to reduction of diapause expression in some populations. We explored the importance of such trade-off through the comparison of cold resistance capacities among different life stages in diapause and non-diapause individuals in a population of the aphid parasitoid Aphidius ervi (Hymenoptera: Braconidae) originating from western France where a decrease of diapause incidence was recently observed. As a proxy measure of insect physiological cold resistance, the Super Cooling Point (SCP) was determined for non-diapausing and diapausing prepupae and adults that went through prepupal diapause or not. Diapausing and non-diapausing prepupae were equally cold-resistant (-24.20 ±0.30°C vs. -24.74 ±0.36°C, respectively), and overall more resistant than adults. Adults that went through diapause as prepupae were less cold resistant (-17.85 ±1.10°C) than adults that have not undergone through diapause (-21.10 ±0.54°C). We also found that diapausing prepupae and adults that have undergone diapause were lighter than their non-diapausing counterparts, at a comparable size, suggesting higher energetic expenses during diapause. These results suggest a trade-off between diapause expression in prepupae and cold resistance and life-history-traits in adults. We conclude that selection could favor insects that do not enter diapause and thus avoid its associated costs while taking advantage at exploiting the mild winter environment.

scholarly journals Attenuation of Wave Energy Due to Mangrove Vegetation off Mumbai, India

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4286 ◽  
Author(s):  
Samiksha S. V. ◽  
P. Vethamony ◽  
Prasad K. Bhaskaran ◽  
P. Pednekar ◽  
M. Jishad ◽  
...  
Keyword(s):  
Climate Change ◽  
Drag Coefficient ◽  
Wave Energy ◽  
Measured Data ◽  
Stem Diameter ◽  
Coastal Hazards ◽  
Sensitivity Analyses ◽  
Vegetation Density ◽  
Mangrove Vegetation ◽  
Set Up

Coastal regions of India are prone to sea level rise, cyclones, storm surges, and human-induced activities, resulting in flood, erosion, and inundation, and some of these impacts could be attributed to climate change. Mangroves play a very protective role against some of these coastal hazards. The primary aim of the study was to estimate wave energy attenuation by mangrove vegetation using modeling, and to validate the model results with measurements conducted off Mumbai coast, where a mangrove forest is present. Wave measurements were carried out from 5–8 August 2015 at three locations in a transect normal to the coast using surface-mounted pressure-level sensors in spring tide conditions. The measured data presented wave height attenuation of the order of 52%. Model set-up and sensitivity analyses were conducted to understand the model performance with respect to vegetation parameters. It was observed that wave attenuation increases with an increase in drag coefficient, vegetation density, and stem diameter. For a typical set-up in the Mumbai coastal region having a vegetation density of 0.175 per m2, stem diameter of 0.3 m, and drag coefficient varying from 0.4 to 1.5, the model reproduced attenuation ranging from 49% to 55%, which matches reasonably well with the measured data. Spectral analysis performed for the cases with and without vegetation very clearly portrays energy dissipation in the vegetation area. This study also highlights the importance of climate change and mangrove vegetation.

Opportunities for harnessing the increased contribution of glacier and snowmelt flows in the Ganges basin

Water Policy ◽  
2013 ◽  
Vol 15 (S1) ◽  
pp. 9-25 ◽  
Author(s):  
Bharat R. Sharma ◽  
Devaraj de Condappa
Keyword(s):  
Climate Change ◽  
Aquifer Recharge ◽  
Eastern India ◽  
Ganges Basin ◽  
Additional Water ◽  
Set Up ◽  
Tehri Dam ◽  
The Ganges ◽  
The Impact ◽  
The Himalaya

The topography of the Ganges basin is highly variable, with the steep mountainous region of the Himalaya upstream and the large fertile plains in eastern India and Bangladesh downstream. The contribution from the glaciers to streamflows is supposed to be significant but there is uncertainty surrounding the impact of climate change on glaciers. An application of the Water Evaluation and Planning model was set up which contained an experimental glaciers module. The model also examined the possible impacts of an increase in temperature. The contribution from glaciated areas is significant (60–75%) in the Upper Ganges but reduces downstream, falling to about 19% at Farakka. Climate change-induced rise in temperature logically increases the quantity of snow and ice that melts in glaciated areas. However, this impact decreases from upstream (+8% to +26% at Tehri dam) to downstream (+1% to +4% at Farakka). Such increases in streamflows may create flood events more frequently, or of higher magnitude, in the upper reaches. Potential strategies to exploit this additional water may include the construction of new dams/reservoir storage and the development of groundwater in the basin through managed aquifer recharge. The riparian states of India, Nepal and Bangladesh could harness this opportunity to alleviate physical water scarcity and improve productivity.

scholarly journals S2P3-R v2.0: computationally efficient modelling of shelf seas on regional to global scales

2021 ◽  
Vol 14 (10) ◽  
pp. 6177-6195
Author(s):  
Paul R. Halloran ◽  
Jennifer K. McWhorter ◽  
Beatriz Arellano Nava ◽  
Robert Marsh ◽  
William Skirving
Keyword(s):  
Climate Change ◽  
Computational Efficiency ◽  
Dynamical Downscaling ◽  
Climate Projections ◽  
Grid Cells ◽  
Computationally Efficient ◽  
Global Models ◽  
Shelf Seas ◽  
Shelf Sea ◽  
Set Up

Abstract. The marine impacts of climate change on our societies will be largely felt through coastal waters and shelf seas. These impacts involve sectors as diverse as tourism, fisheries and energy production. Projections of future marine climate change come from global models. Modelling at the global scale is required to capture the feedbacks and large-scale transport of physical properties such as heat, which occur within the climate system, but global models currently cannot provide detail in the shelf seas. Version 2 of the regional implementation of the Shelf Sea Physics and Primary Production (S2P3-R v2.0) model bridges the gap between global projections and local shelf-sea impacts. S2P3-R v2.0 is a highly simplified coastal shelf model, computationally efficient enough to be run across the shelf seas of the whole globe. Despite the simplified nature of the model, it can display regional skill comparable to state-of-the-art models, and at the scale of the global (excluding high latitudes) shelf seas it can explain >50 % of the interannual sea surface temperature (SST) variability in ∼60 % of grid cells and >80 % of interannual variability in ∼20 % of grid cells. The model can be run at any resolution for which the input data can be supplied, without expert technical knowledge, and using a modest off-the-shelf computer. The accessibility of S2P3-R v2.0 places it within reach of an array of coastal managers and policy makers, allowing it to be run routinely once set up and evaluated for a region under expert guidance. The computational efficiency and relative scientific simplicity of the tool make it ideally suited to educational applications. S2P3-R v2.0 is set up to be driven directly with output from reanalysis products or daily atmospheric output from climate models such as those which contribute to the sixth phase of the Climate Model Intercomparison Project, making it a valuable tool for semi-dynamical downscaling of climate projections. The updates introduced into version 2.0 of this model are primarily focused around the ability to geographical relocate the model, model usability and speed but also scientific improvements. The value of this model comes from its computational efficiency, which necessitates simplicity. This simplicity leads to several limitations, which are discussed in the context of evaluation at regional and global scales.

scholarly journals Potential impacts of climate change on Mongolia’s plant protection status quo

2018 ◽  
Vol 24 (02) ◽  
pp. 26-32
Author(s):  
Batkhuyag B ◽  
Batnaran Kh
Keyword(s):  
Climate Change ◽  
Climate Modeling ◽  
Plant Protection ◽  
Current Trend ◽  
Animal Husbandry ◽  
Distribution Patterns ◽  
Agricultural Pests ◽  
Migratory Locust ◽  
Colorado Beetle ◽  
Wide Range

Mongolia’s 2030 Sustainable Development Vision set a goal to be a self-sufficient in grain, potatoes and vegetables by 2030. However, Mongolia’s pastoral animal husbandry and rain-fed agriculture are extremely sensitive to climate change. The Asian migratory locust is considered as the most harmful grasshopper in the world. Until 1970th, these locust’s distribution areas in Mongolia were confined to oasis of Gobi deserts. A study on Asian migratory locust in Russia predicts distribution and formation of new permanent habitats of the locust in Chita oblast, Krasnoyarsk territory and Republic of Tyva. The Colorado beetle is one of the world’s most infamous invasive species due to its rapid adaptation to a wide range of ecological conditions and ability to disperse long distances. The climate modeling of Colorado beetle showed that with current trend, the beetle will expand its distribution into the most eastern and north-eastern regions of the Russian Federation. In China, the Colorado beetle was first detected in Xinjiang in 1993 and subsequently spread eastward. In China the Colorado beetle is currently expanding its areas at rate of 25 kms year (12-45 kms/year). Both species’ distribution patterns in neighboring countries show eventual establishment of permanent habitats around Mongolia. Their invasion to Mongolia will threaten country’s food security due to direct destruction of cereal and potato crops, and increased application of highly toxic pesticides. In light of these threats, Mongolia should start taking serious preventive measures by increasing surveillance and dedicated risk assessment studies for potential agricultural pests and diseases.

Impact of Climate Change on a Key Agricultural Pest

2018 ◽  
pp. 65-87 ◽  
Author(s):  
Tamika A. Garrick ◽  
Oscar E. Liburd
Keyword(s):  
Climate Change ◽  
Developing Countries ◽  
Agricultural Production ◽  
Management Strategies ◽  
Human Consumption ◽  
Agricultural Pests ◽  
Tropical Regions ◽  
Pests And Diseases ◽  
Thrips Species ◽  
Rising Sea Levels

The world population is expected to exceed 9 billion by 2050 and most of this growth will occur in developing countries. As population increases, more arable lands will be used to construct cities and these activities increase CO2 in the atmosphere and contribute to climate change. Climate assessments have shown rising sea levels and increase in the frequency of droughts in many dry areas. Prolonged droughts can decrease the relative amounts of water available for human consumption and agriculture. In developing countries agriculture contributes to more than 15% of GDP and when crops and livestock are deprived of water they become more susceptible to pests and diseases. As climate change continues to occur there is a need to develop strategies to manage key invasive pest and disease species that threaten agricultural production. Thrips are major agricultural pests with the majority of species in tropical regions. They are cosmopolitan in nature and damage crops when they feed and lay eggs in many parts of the plant. Thrips are also vectors for spreading plant diseases. They disperse quickly into new areas where susceptible hosts exist. This chapter focuses on a few important thrips species that threatens agricultural production in the Americas including Central and South America and the Caribbean. The chapter discusses the ecology and pest management strategies for key invasive thrips species and examines the potential effects of climate change on these troublesome species.

Seasonal temperature variations influence tapetum mitosis patterns associated with reproductive fitness

Genome ◽  
2014 ◽  
Vol 57 (9) ◽  
pp. 517-521 ◽  
Author(s):  
Umesh C. Lavania ◽  
Surochita Basu ◽  
Jyotsana Singh Kushwaha ◽  
Seshu Lavania
Keyword(s):  
Climate Change ◽  
Temperature Change ◽  
Reproductive Fitness ◽  
Seasonal Temperature ◽  
Seed Fertility ◽  
Mild Winter ◽  
Differential Behavior ◽  
Sporogenous Tissue ◽  
Differential Behaviour ◽  
Environmentally Sensitive

Environmental stress in plants impacts many biological processes, including male gametogenesis, and affects several cytological mechanisms that are strongly interrelated. To understand the likely impact of rising temperature on reproductive fitness in the climate change regime, a study of tapetal mitosis and its accompanying meiosis over seasons was made to elucidate the influence of temperature change on the cytological events occurring during microsporogenesis. For this we used two species of an environmentally sensitive plant system, i.e., genus Cymbopogon Sprengel (Poaceae), namely Cymbopogon nardus (L.) Rendle var. confertiflorus (Steud.) Bor (2n = 20) and Cymbopogon jwaruncusha (Jones) Schult. (2n = 20). Both species flower profusely during extreme summer (48 °C) and mild winter (15 °C) but support low and high seed fertility, respectively, in the two seasons. We have shown that tapetal mitotic patterns over seasons entail differential behavior for tapetal mitosis. During the process of tapetum development there are episodes of endomitosis that form either (i) an endopolyploid genomically imbalanced uninucleate and multinucleate tapetum, and (or) (ii) an acytokinetic multinucleate genomically balanced tapetum, with the progression of meiosis in the accompanying sporogenous tissue. The relative frequency of occurrence of the two types of tapetum mitosis patterns is significantly different in the two seasons, and it is found to be correlated with the temperature conditions. Whereas, the former (genomically imbalanced tapetum) are prevalent during the hot summer, the latter (genomically balanced tapetum) are frequent under optimal conditions. Such a differential behaviour in tapetal mitosis vis-à-vis temperature change is also correspondingly accompanied by substantial disturbances or regularity in meiotic anaphase disjunction. Both species show similar patterns. The study underpins that tapetal mitotic behaviour per se could be a reasonable indicator to elucidate the effect of climate change on reproductive fitness.

CONSPECIFIC SUPERPARASITISM IN TWO PARASITOID WASPS, APHIDIUS ERVI HALIDAY AND APHELINUS ASYCHIS WALKER: REPRODUCTIVE STRATEGIES INFLUENCE HOST DISCRIMINATION

1991 ◽  
Vol 123 (6) ◽  
pp. 1229-1237 ◽  
Author(s):  
B. Bai
Keyword(s):  
Reproductive Strategies ◽  
Acyrthosiphon Pisum ◽  
Aphidius Ervi ◽  
Parasitoid Wasps ◽  
Host Discrimination ◽  
Larval Competition ◽  
Parasitoid Species ◽  
Aphid Parasitoid ◽  
Aphelinus Asychis ◽  
Physiological Suppression

AbstractConspecific host discrimination and larval competition in two aphid parasitoid species were studied in the laboratory using the pea aphid, Acyrthosiphon pisum (Harris) (Homoptera: Aphididae), as a host. Aphidius ervi Haliday (Hymenoptera: Aphidiidae) used internal host cues to discriminate between unparasitized and conspecific parasitized hosts. When only parasitized hosts were available, females oviposited into recently parasitized ones where their progeny had a good chance to survive, but rejected those parasitized ≥24 h earlier where their offspring normally died. Competitions occurred only after both eggs had hatched. Larvae eliminated supernumeraries by means of physical combat and physiological suppression. In Aphelinus asychis Walker (Hymenoptera: Aphelinidae), factors, or changes in host internal condition, associated with hatching of the first egg resulted in suppression of conspecific competitors which could be in either larval or egg stage. The older larvae always won competitions through physiological means. A wasp’s oviposition decision is shown to be influenced by the probability of its progeny’s survival. Species that have different reproductive strategies may respond differently to identical host conditions.

scholarly journals Food and sustainability challenges under climate change

2018 ◽  
Author(s):  
Khaled Moustafa
Keyword(s):  
Climate Change ◽  
Solar Energy ◽  
Traffic Lights ◽  
The Past ◽  
Natural Factors ◽  
The World ◽  
Save Energy ◽  
Set Up ◽  
Sustainability Challenges ◽  
Living Accommodation

Plants are permanently impacted by their environments, and their abilities to tolerate multiple fluctuating environmental conditions vary as a function of several genetic and natural factors. Over the past decades, scientific innovations and applications of the knowledge derived from biotechnological investigations to agriculture caused a substantial increase of the yields of many crops. However, due to exacerbating effects of climate change and a growing human population, a crisis of malnutrition may arise in the upcoming decades in some places in the world. So, effective, ethical and managerial regulations and fair policies should be set up and applied at the local and global levels so that Earth may fairly provide the food and living accommodation needed by its inhabitants. To save some energy consumption, electric devices (for e.g., smartphones, laptops, street lights, traffic lights, etc.) should be manufactured to work with solar energy, whenever available, particularly in sunny countries where sun is available most of the time. Such characteristic will save energy and make solar energy-based smartphones and laptops less cumbersome in terms of chargers and plugging issues.

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