scholarly journals Adult facilitation becomes competition as juvenile soapberry bugs age

2017 ◽  
Author(s):  
Meredith L Cenzer
Keyword(s):  
Host Plant ◽  
Intraspecific Interactions ◽  
Plant Feeding ◽  
Soapberry Bug ◽  
Adult Feeding ◽  
Negative Effect ◽  
Jadera Haematoloma ◽  
Native Host ◽  
Experienced Adult

ABSTRACTWhether intraspecific interactions are facilitative or competitive may change across individual ontogeny. In plant-feeding insects, the direction of this interaction is likely to be mediated by host plant defenses. Here I conducted two experiments looking at the direct effect of a physical seed defense and the role of intraspecific facilitation in reducing the effects of that defense for juveniles. I first demonstrate that juveniles of the red-shouldered soapberry bug (Jadera haematoloma) are severely inhibited by the tough seed coat of their host plant, leading to high mortality early in development. Adults, in contrast, can create holes through which other individuals could potentially feed. I then manipulated whether or not seeds experienced adult feeding on two host plant species: a well-defended native host, balloon vine (Cardiospermum corindum) and a poorly defended introduced golden rain tree species (Koelreuteria elegans). I measured the effect of prior adult feeding on survival, development time, and final body size of soapberry bug juveniles. Survival in the first week of development was dramatically improved by prior adult feeding on both hosts. However, the benefits of prior adult feeding ceased after the first week of development and shifted to having a negative effect on performance. These results indicate that adults breaking through the seedcoat initially facilitate juveniles, but that this facilitation becomes competition as juveniles age.

scholarly journals Natural selection and maladaptive plasticity in the red-shouldered soapberry bug

2016 ◽  
Author(s):  
M L Cenzer
Keyword(s):  
Gene Flow ◽  
Natural Selection ◽  
Phenotypic Plasticity ◽  
Host Plant ◽  
Individual Performance ◽  
Negative Effects ◽  
Soapberry Bug ◽  
Maladaptive Plasticity ◽  
Beak Length ◽  
Native Host

AbstractNatural selection and phenotypic plasticity can both produce locally differentiated phenotypes, but novel environments or gene combinations can produce plasticity that works in opposition to adaptive change. The red-shouldered soapberry bug (Jadera haematoloma) was locally adapted to feed on the seeds of an introduced and a native host plant in Florida in the 1980s. By 2014, local differentiation was lost and replaced by phenotypically similar populations all adapted to the introduced host, likely as a result of gene flow. Here, I quantify the effects of these two host plants on individual performance, natural selection, and phenotypic plasticity. I find that the seed coat and seedpod of the native host have strong negative effects on juvenile survival and adult reproduction compared to the introduced host. I find support for the hypothesis that the seedpod is driving diversifying natural selection on beak length, which was previously locally adapted between hosts. I also find maladaptive plasticity induced by host plant: bugs develop beak lengths that are mismatched with the seedpod size of the host they are reared on. This plasticity may be the result of gene flow; hybrids in the 1990s showed the same pattern of maladaptive plasticity, and plasticity is stronger in the present in areas with high gene flow. Although ongoing natural selection has produced locally adapted genotypes in soapberry bugs, maladaptive plasticity has masked the phenotypic difference between populations in the field.

Adaptation to an invasive host is collapsing a native ecotype

2015 ◽  
Author(s):  
Meredith L Cenzer
Keyword(s):  
Invasive Species ◽  
Gene Flow ◽  
Host Plant ◽  
Local Adaptation ◽  
Ecological Speciation ◽  
Model Systems ◽  
Native Communities ◽  
Multiple Phenotypes ◽  
Jadera Haematoloma ◽  
Native Host

Locally adapted populations are often used as model systems for the early stages of ecological speciation, but most of these young divergent lineages will never become complete species. While the collapse of incipient species is theoretically common, very few examples have been documented in nature. Here I show that soapberry bugs (Jadera haematoloma) have lost adaptations to their native host plant (Cardiospermum corindum) and are regionally specializing on an invasive host plant (Koelreuteria elegans), collapsing a classic and well-documented example of local adaptation. All populations that were adapted to the native host - including those still found on that host today - are now better adapted to the invasive in multiple phenotypes. Weak differentiation remains in two traits, suggesting that homogenization across the region is incomplete. This study highlights the potential for adaptation to invasive species to disrupt native communities by swamping adaptation to native conditions through maladaptive gene flow.

Social Motives Predict Loneliness During a Developmental Transition

2017 ◽  
Vol 76 (4) ◽  
pp. 145-153 ◽  
Author(s):  
Jana Nikitin ◽  
Alexandra M. Freund
Keyword(s):  
Social Relationships ◽  
Well Being ◽  
Social Avoidance ◽  
Social Approach ◽  
Social Motives ◽  
Developmental Transitions ◽  
Avoidance Motivation ◽  
Negative Effect ◽  
Low Levels

Abstract. Establishing new social relationships is important for mastering developmental transitions in young adulthood. In a 2-year longitudinal study with four measurement occasions (T1: n = 245, T2: n = 96, T3: n = 103, T4: n = 85), we investigated the role of social motives in college students’ mastery of the transition of moving out of the parental home, using loneliness as an indicator of poor adjustment to the transition. Students with strong social approach motivation reported stable and low levels of loneliness. In contrast, students with strong social avoidance motivation reported high levels of loneliness. However, this effect dissipated relatively quickly as most of the young adults adapted to the transition over a period of several weeks. The present study also provides evidence for an interaction between social approach and social avoidance motives: Social approach motives buffered the negative effect on social well-being of social avoidance motives. These results illustrate the importance of social approach and social avoidance motives and their interplay during developmental transitions.

Endangered Butterflies and their Non-Native Host Plants: Examining Shifting Values of Belonging in Restoration

2019 ◽  
Vol 3 (1) ◽  
pp. 1-9
Author(s):  
Robert M. Anderson ◽  
Amy M. Lambert
Keyword(s):  
Ecological Restoration ◽  
Native Species ◽  
Puget Sound ◽  
A Value ◽  
The Social ◽  
Remote Island ◽  
Scientific Truth ◽  
Native Host

The island marble butterfly (Euchloe ausonides insulanus), thought to be extinct throughout the 20th century until re-discovered on a single remote island in Puget Sound in 1998, has become the focus of a concerted protection effort to prevent its extinction. However, efforts to “restore” island marble habitat conflict with efforts to “restore” the prairie ecosystem where it lives, because of the butterfly’s use of a non-native “weedy” host plant. Through a case study of the island marble project, we examine the practice of ecological restoration as the enactment of particular norms that define which species are understood to belong in the place being restored. We contextualize this case study within ongoing debates over the value of “native” species, indicative of deep-seated uncertainties and anxieties about the role of human intervention to alter or manage landscapes and ecosystems, in the time commonly described as the “Anthropocene.” We interpret the question of “what plants and animals belong in a particular place?” as not a question of scientific truth, but a value-laden construct of environmental management in practice, and we argue for deeper reflexivity on the part of environmental scientists and managers about the social values that inform ecological restoration.

THE NOTHING THAT REALLY IS!

2016 ◽  
Vol 12 (1) ◽  
pp. 4172-4177
Author(s):  
Abdul Malek
Keyword(s):  
Quantum Dynamics ◽  
Theoretical Physics ◽  
Historical Evolution ◽  
Proper Understanding ◽  
Physical Universe ◽  
Wave Particle Duality ◽  
Negative Effect ◽  
Materialist Interpretation

The denial of the existence of contradiction is at the root of all idealism in epistemology and the cause for alienations.  This alienation has become a hindrance for the understanding of the nature and the historical evolution mathematics itself and its role as an instrument in the enquiry of the physical universe (1). A dialectical materialist approach incorporating  the role of the contradiction of the unity of the opposites, chance and necessity etc., can provide a proper understanding of the historical evolution of mathematics and  may ameliorate  the negative effect of the alienation in modern theoretical physics and cosmology. The dialectical view also offers a more plausible materialist interpretation of the bewildering wave-particle duality in quantum dynamics (2).

Peran Badan Pengendalian Dampak Lingkungan dalam Pengendalian Dampak Pencemaran Kegiatan Industri di Kota Batam tahun 2011-2014

2015 ◽  
Vol 14 (1) ◽  
pp. 20
Author(s):  
Wan Asrida ◽  
Dian Arival Aryadana
Keyword(s):  
Environmental Impact ◽  
Environmental Pollution ◽  
Pollution Control ◽  
Control Agency ◽  
Accurate Method ◽  
Industrial Activity ◽  
Research Issues ◽  
Negative Effect ◽  
Research Show

This research is intended to find out the role of the regional environmental impact Control Agency of Batam City against the environmental problems that occur in industrial areas namely, Batam city, concerning sustainable development based upon the environment, the activities of the industry now aims to build an economic sector but has a negative effect that is the pollution of the environment. In this case in Batam city frequent occurrence of environmental pollution caused by industrial activity namely with disposal of waste which are not in place. This research is focused on environmental impact Control Agency area of Batam city authorities in the control of the environment . With the outline of the research issues namely how environmental impact Control Agency the role of the Regions in the control of pollution of the environment against industrial activity in Batam city in 2011-2014 and the factors restricting the role of the regional environmental impact Control Agency in controlling environmental pollution in Batam city in 2011-2014.Type of this research is a descriptive i.e. researchers provide a description and overview of the phenomenon or social symptoms examined by independent variables described in a systematic and accurate. Method of data collection is done by means of interviews and the documentation.The results of this research show that the role of environmental impact Control Agency area of Batam city in pollution control against industrial activity carried out according to its function but have not run well in accordance with the goals and targets that have been set. This is not in accordance with the duties and functions of the regional environmental impact Control Agency of Batam city, resulting in less the maximum role of Bapedalda itself in controlling pollution that occurred in Batam city. So it should be should be able to stake Bapedalda holder which is professional in the discharge of pollution control and must be capable of tackling the obstacles faced.

The path of support-to-sales: mediating role of seller collaborative information exchange in social commerce

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Li Chen ◽  
Fengxia Zhu ◽  
Murali Mantrala
Keyword(s):  
Information Exchange ◽  
Instrumental Support ◽  
Trade Volume ◽  
Social Commerce ◽  
Content Type ◽  
Mediating Role ◽  
The Social ◽  
Source Data ◽  
Negative Effect

Purpose This paper aims to systematically investigate the direct and indirect effects of four types of support – peer instrumental support, peer emotional support, platform business support and platform communication support – on seller trade volume in social commerce. It also aims to uncover the path of support-to-sales of the seller from a platform perspective and provides a more complete picture of the social commerce phenomenon. Design/methodology/approach This paper uses multi-source data including primary survey data and secondary data on trade volume to test the hypotheses. PROCESS mediation model is used to analyze the multi-source data set. Findings This study finds that the positive effects of peer instrumental support, platform business support and platform communication support on seller trade volume are fully mediated by seller collaborative information exchange. Also, peer emotional support has a significant negative effect on seller trade volume and collaborative information exchange can serve as a buffer to mitigate the negative effect. Research limitations/implications The authors provide new insights into what types of support are or are not conducive to improving transaction volume of individual sellers and highlight the mediating role of seller information exchange in this value generation process in social commerce. These findings advance current knowledge of how seller interactions increase value in social commerce. The chosen research setting may limit the generalizability of the findings of this study. Practical implications This paper offers valuable implications for social commerce platforms on how to better serve their sellers to achieve high growth. Specifically, the findings suggest that platforms should encourage instrumental support and information exchange among peer sellers. In addition, platforms should expand seller support from a single-focus on sellers’ business to a dual-focus on both sellers’ business and socialization in social commerce. Originality/value This paper fulfills an identified need to study how sellers can better derive value from the social interactions and how social commerce platforms can effectively influence transactions, support sales and serve as a selling platform.

scholarly journals Effects of Vector Maturation Time on the Dynamics of Cassava Mosaic Disease

2021 ◽  
Vol 83 (8) ◽  
Author(s):  
F. Al Basir ◽  
Y. N. Kyrychko ◽  
K. B. Blyuss ◽  
S. Ray
Keyword(s):  
Time Delay ◽  
Plant Density ◽  
Plant Viruses ◽  
Mosaic Disease ◽  
Plant Diseases ◽  
Cassava Mosaic Disease ◽  
Maturation Time ◽  
Negative Effect ◽  
Dynamical Regimes

AbstractMany plant diseases are caused by plant viruses that are often transmitted to plants by vectors. For instance, the cassava mosaic disease, which is spread by whiteflies, has a significant negative effect on plant growth and development. Since only mature whiteflies can contribute to the spread of the cassava mosaic virus, and the maturation time is non-negligible compared to whitefly lifetime, it is important to consider the effects this maturation time can have on the dynamics. In this paper, we propose a mathematical model for dynamics of cassava mosaic disease that includes immature and mature vectors and explicitly includes a time delay representing vector maturation time. A special feature of our plant epidemic model is that vector recruitment is negatively related to the delayed ratio between vector density and plant density. We identify conditions of biological feasibility and stability of different steady states in terms of system parameters and the time delay. Numerical stability analyses and simulations are performed to explore the role of various parameters, and to illustrate the behaviour of the model in different dynamical regimes. We show that the maturation delay may stabilise epidemiological dynamics that would otherwise be cyclic.

scholarly journals Drought and Salinity in Citriculture: Optimal Practices to Alleviate Salinity and Water Stress

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1283
Author(s):  
Vasileios Ziogas ◽  
Georgia Tanou ◽  
Giasemi Morianou ◽  
Nektarios Kourgialas
Keyword(s):  
Agricultural Sector ◽  
Review Paper ◽  
Cell Metabolism ◽  
High Water ◽  
Crop Productivity ◽  
Fruit Tree ◽  
Key Factors ◽  
Negative Effect

Among the various abiotic stresses, drought is the major factor limiting crop productivity worldwide. Citrus has been recognized as a fruit tree crop group of great importance to the global agricultural sector since there are 140 citrus-producing countries worldwide. The majority of citrus-producing areas are subjected to dry and hot summer weather, limited availability of water resources with parallel low-quality irrigation water due to increased salinity regimes. Citrus trees are generally classified as “salt-intolerant” with high water needs, especially during summer. Water scarcity negatively affects plant growth and impairs cell metabolism, affecting the overall tree growth and the quality of produced fruit. Key factors that overall attempt to sustain and withstand the negative effect of salinity and drought stress are the extensive use of rootstocks in citriculture as well as the appropriate agronomical and irrigation practices applied. This review paper emphasizes and summarizes the crucial role of the above factors in the sustainability of citriculture.

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