Search results for "PIDE"
showing 10 items of 6055 documents
Increasing temperatures accentuate negative fitness consequences of a marine parasite
2020
AbstractInfectious diseases are key drivers of wildlife populations and agriculture production, but whether and how climate change will influence disease impacts remains controversial. One of the critical knowledge gaps that prevents resolution of this controversy is a lack of high-quality experimental data, especially in marine systems of significant ecological and economic consequence. Here, we performed a manipulative experiment in which we tested the temperature-dependent effects on Atlantic salmon (Salmo salar) of sea lice (Lepeophtheirus salmonis)—a parasite that can depress the productivity of wild-salmon populations and the profits of the salmon-farming industry. We explored sea-lou…
Survey of the distribution of Bemisia tabaci (Hemiptera: Aleyrodidae) in Lazio region (Central Italy): a threat for the northward expansion of Tomato…
2018
Bemisia tabaci (Hemiptera: Aleyrodidae) is responsible for severe damage to horticultural and ornamental crops worldwide, mainly for its role as virus vector. In Italy, the B. tabaci Mediterranean (MED) and Middle East–Asia Minor 1 (MEAM1) cryptic species are widespread in the Southern regions as well as in Sicily and Sardinia. During the last two decades, MED populations progressively increased, in those areas where intensive farming is applied. The recent introduction of the begomovirus Tomato leaf curl New Delhi virus (ToLCNDV) prompted extensive surveys of both vector and symptomatic plants. In 2016 and 2017, monitoring activities were carried out in Lazio region (Central Italy) where b…
Non-consumptive effects between predators depend on the foraging mode of intraguild prey.
2020
Predator non-consumptive effects (NCE) are a suite of phenotypic responses of prey to avoid predation that cascade down food webs and can have a stronger impact than predation itself. However, the role of NCE in intraguild interactions remains understudied. Thus, multi-species experiments based on species traits are needed to improve our understanding of the impact of NCE on community structure. We investigated NCE of ants on 17 spider species as intraguild prey (8 cursorial and 9 sedentary) to test the influence of spider hunting mode on the strength of NCE. Sedentary spiders select a habitat patch and wait for prey, whereas cursorial spiders roam around searching for prey. Because activel…
Stomatal deregulation in Plasmopara viticola-infected grapevine leaves.
2007
International audience; In grapevine, the penetration and sporulation of Plasmopara viticola occur via stomata, suggesting functional relationships between guard cells and the pathogen. This assumption was supported by our first observation that grapevine (Vitis vinifera cv. Marselan) cuttings infected by P. viticola wilted more rapidly than healthy ones when submitted to water starvation. • Here, complementary approaches measuring stomatal conductance and infrared thermographic and microscopic observations were used to investigate stomatal opening/closure in response to infection. • In infected leaves, stomata remained open in darkness and during water stress, leading to increased transpir…
Vector activity of Hyalesthes obsoletus living on nettles and transmitting a stolbur phytoplasma to grapevines: a case study
2007
International audience; We report a case study on the vector activity of a Hyalesthes obsoletus (Hemiptera: Cixiidae) population living on nettle plants (Urtica dioica) and transmitting a stolbur phytoplasma (Sp) to grapevines (Vitis vinifera). The research was conducted in a site that included a vineyard bordered with a large fallow area where nettles were the predominant plant species together with sparse old grapevines. Nettles hosted a high population of H. obsoletus. By using transparent sticky traps to sample adults, we observed that the daily flight activity of males and females to grapevines in the fallow was unimodal peaking between 15 and 21 h in the day. Adults were unable of gre…
Increasing water temperature and disease risks in aquatic systems: Climate change increases the risk of some, but not all, diseases
2010
Global warming may impose severe risks for aquatic animal health if increasing water temperature leads to an increase in the incidence of parasitic diseases. Essentially, this could take place through a temperature-driven effect on the epidemiology of the disease. For example, higher temperature may boost the rate of disease spread through positive effects on parasite fitness in a weakened host. Increased temperature may also lengthen the transmission season leading to higher total prevalence of infection and more widespread epidemics. However, to date, general understanding of these relationships is limited due to scarcity of long-term empirical data. Here, we present one of the first long…
Environmental change and disease dynamics: effects of intensive forest management on Puumala hantavirus infection in boreal bank vole populations.
2012
Intensive management of Fennoscandian forests has led to a mosaic of woodlands in different stages of maturity. The main rodent host of the zoonotic Puumala hantavirus (PUUV) is the bank vole (Myodes glareolus), a species that can be found in all woodlands and especially mature forests. We investigated the influence of forest age structure on PUUV infection dynamics in bank voles. Over four years, we trapped small mammals twice a year in a forest network of different succession stages in Northern Finland. Our study sites represented four forest age classes from young (4 to 30 years) to mature (over 100 years) forests. We show that PUUV-infected bank voles occurred commonly in all forest age…
Parasite and host assemblages: embracing the reality will improve our knowledge of parasite transmission and virulence.
2010
10 pages; International audience; Interactions involving several parasite species (multi-parasitized hosts) or several host species (multi-host parasites) are the rule in nature. Only a few studies have investigated these realistic, but complex, situations from an evolutionary perspective. Consequently, their impact on the evolution of parasite virulence and transmission remains poorly understood. The mechanisms by which multiple infections may influence virulence and transmission include the dynamics of intrahost competition, mediation by the host immune system and an increase in parasite genetic recombination. Theoretical investigations have yet to be conducted to determine which of these…
Specific color sensitivities of prey and predator explain camouflage in different visual systems
2004
In situations of aggressive mimicry, predators adapt their color to that of the substrate on which they sit for hunting, a behavior that is presumed to hide them from prey as well as from their own predators. Females of few crab-spider species encounter such situations when lying on flowers to ambush pollinators. To evaluate the efficiency of spider camouflage on flowers, we measured by spectroradiometry adult female Thomisus onustus and marguerite daisies, Leucanthemum vulgare. We compared chromatic contrast (color used for short-range detection) of each pair of spider and flower to detection thresholds computed in the visual systems of both Hymenopteran prey and passerine bird predator. W…
Unpredicted ecological and ecosystem services of biodiversity. Spontaneous vegetation, hedgerows, and maple trees as useful landscape components to i…
2020
Abstract Rural landscapes have been dramatically simplified and reduced. Large mechanical machinery was adopted and most of the natural helps such as living tutors in the vineyards disappeared or were replaced by cement or steel pillars. In the same way, field margins and hedgerows have also become restricted and simplified. The vegetation in the rural landscape mosaic provides alternative food and overwintering places, maintaining the inestimable importance of biodiversity in providing unexpected ecological services in agroecosystems. An important example could be predatory mites both as species and population density, providing ecological service for biological control such as the two-spo…