The Experts below are selected from a list of 40122 Experts worldwide ranked by ideXlab platform
Gregory D D Hurst - One of the best experts on this subject based on the ideXlab platform.
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solving the wolbachia paradox modeling the tripartite interaction between host wolbachia and a Natural Enemy
The American Naturalist, 2011Co-Authors: Andy Fenton, Karyn N Johnson, Jeremy C Brownlie, Gregory D D HurstAbstract:AbstractWolbachia is one of the most common symbionts of arthropods. Its establishment requires lateral transfer to and successful transmission within novel host species. However, Wolbachia performs poorly when introduced into new host species, and models predict that Wolbachia should seldom be able to establish from low initial frequencies. Recently, various symbionts, including Wolbachia, have been shown to protect their hosts from Natural enemies. Hence, Wolbachia invasion may be facilitated by the dynamic interaction between it, its host, and a Natural Enemy. We model such an interaction whereby Wolbachia induces either complete resistance, partial resistance, or tolerance to a host-specific pathogen and also induces the common manipulation phenotype of cytoplasmic incompatibility (CI). We show that the presence of the pathogen greatly facilitates Wolbachia invasion from rare and widens the parameter space in which “imperfect” Wolbachia strains can invade. Furthermore, positive frequency-dependent sel...
Nicolas Desneux - One of the best experts on this subject based on the ideXlab platform.
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Characterization of the Natural Enemy community attacking cotton aphid in the bt cotton ecosystem in northern china
Scientific Reports, 2016Co-Authors: Abid Ali, Nicolas Desneux, Bing LiuAbstract:Planting Bt cotton in China since 1997 has led to important changes in the Natural Enemy communities occurring in cotton, however their specific effect on suppressing the cotton aphids (being notorious in conventional cotton ecosystem) has not been fully documented yet. We observed strong evidence for top-down control of the aphid population, e.g. the control efficiency of Natural enemies on cotton aphid increased significantly in open field cages compared to exclusion cages, accounted for 60.2, 87.2 and 76.7% in 2011, 2012 and 2013 season, respectively. The cotton aphid populations peaked in early June to late July (early and middle growth stages) in open field cotton survey from 2011 to 2013. The population densities of cotton aphids and Natural enemies were highest on middle growth stage while lowest densities were recorded on late stage for aphids and on early plant stage for Natural enemies. Aphid parasitoids (Trioxys spp., Aphidius gifuensis), coccinellids and spiders were key Natural enemies of cotton aphid. Briefly, Natural enemies can suppress aphid population increase from early to middle plant growth stages by providing biocontrol services in Chinese Bt cotton.
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Natural Enemy mediated indirect interactions among prey species potential for enhancing biocontrol services in agroecosystems
Pest Management Science, 2014Co-Authors: Anais Chailleux, Emily K Mohl, Mickael Teixeira Alves, Gerben J. Messelink, Nicolas DesneuxAbstract:Understanding how arthropod pests and their Natural enemies interact in complex agroecosystems is essential for pest management programmes. Theory predicts that prey sharing a predator, such as a biological control agent, can indirectly reduce each other's density at equilibrium (apparent competition). From this premise, we (i) discuss the complexity of indirect interactions among pests in agroecosystems and highlight the importance of Natural Enemy-mediated indirect interactions other than apparent competition, (ii) outline factors that affect the nature of Enemy-mediated indirect interactions in the field and (iii) identify the way to manipulate Enemy-mediated interactions for biological control. We argue that there is a need to increase the link between community ecology theory and biological control to develop better agroecological methods of crop protection via conservation biological control. In conclusion, we identify (i) interventions to be chosen depending on agroecosystem characteristics and (ii) several lines of research that will improve the potential for Enemy-mediated indirect interactions to be applied to biological control. © 2014 Society of Chemical Industry
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Natural Enemy‐mediated indirect interactions among prey species: potential for enhancing biocontrol services in agroecosystems
Pest management science, 2014Co-Authors: Anais Chailleux, Emily K Mohl, Mickael Teixeira Alves, Gerben J. Messelink, Nicolas DesneuxAbstract:Understanding how arthropod pests and their Natural enemies interact in complex agroecosystems is essential for pest management programmes. Theory predicts that prey sharing a predator, such as a biological control agent, can indirectly reduce each other's density at equilibrium (apparent competition). From this premise, we (i) discuss the complexity of indirect interactions among pests in agroecosystems and highlight the importance of Natural Enemy-mediated indirect interactions other than apparent competition, (ii) outline factors that affect the nature of Enemy-mediated indirect interactions in the field and (iii) identify the way to manipulate Enemy-mediated interactions for biological control. We argue that there is a need to increase the link between community ecology theory and biological control to develop better agroecological methods of crop protection via conservation biological control. In conclusion, we identify (i) interventions to be chosen depending on agroecosystem characteristics and (ii) several lines of research that will improve the potential for Enemy-mediated indirect interactions to be applied to biological control.
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Natural Enemy-mediated indirect interactions among prey species: potential for enhancing biocontrol services in agroecosystems
Pest Management Science, 2014Co-Authors: Anais Chailleux, Emily K Mohl, Gerben J. Messelink, Mickaël Teixeira Alves, Nicolas DesneuxAbstract:Understanding how arthropod pests and their Natural enemies interact in complex agroecosystems is essential for pest management programmes. Theory predicts that prey sharing a predator, such as a biological control agent, can indirectly reduce each other's density at equilibrium (apparent competition). From this premise, we (i) discuss the complexity of indirect interactions among pests in agroecosystems and highlight the importance of Natural Enemy-mediated indirect interactions other than apparent competition, (ii) outline factors that affect the nature of Enemy-mediated indirect interactions in the field and (iii) identify the way to manipulate Enemy-mediated interactions for biological control. We argue that there is a need to increase the link between community ecology theory and biological control to develop better agroecological methods of crop protection via conservation biological control. In conclusion, we identify (i) interventions to be chosen depending on agroecosystem characteristics and (ii) several lines of research that will improve the potential for Enemy-mediated indirect interactions to be applied to biological control.
Andy Fenton - One of the best experts on this subject based on the ideXlab platform.
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solving the wolbachia paradox modeling the tripartite interaction between host wolbachia and a Natural Enemy
The American Naturalist, 2011Co-Authors: Andy Fenton, Karyn N Johnson, Jeremy C Brownlie, Gregory D D HurstAbstract:AbstractWolbachia is one of the most common symbionts of arthropods. Its establishment requires lateral transfer to and successful transmission within novel host species. However, Wolbachia performs poorly when introduced into new host species, and models predict that Wolbachia should seldom be able to establish from low initial frequencies. Recently, various symbionts, including Wolbachia, have been shown to protect their hosts from Natural enemies. Hence, Wolbachia invasion may be facilitated by the dynamic interaction between it, its host, and a Natural Enemy. We model such an interaction whereby Wolbachia induces either complete resistance, partial resistance, or tolerance to a host-specific pathogen and also induces the common manipulation phenotype of cytoplasmic incompatibility (CI). We show that the presence of the pathogen greatly facilitates Wolbachia invasion from rare and widens the parameter space in which “imperfect” Wolbachia strains can invade. Furthermore, positive frequency-dependent sel...
Alexandra-maria Klein - One of the best experts on this subject based on the ideXlab platform.
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Diversity and specificity of host-Natural Enemy interactions in an urban-rural interface
Ecological Entomology, 2016Co-Authors: Maria Helena Pereira-peixoto, Gesine Pufal, Michael Staab, Celso Feitosa Martins, Alexandra-maria KleinAbstract:1. Urbanisation and agricultural intensification cause the replacement of Natural ecosystems but might also create novel habitats in urban and rural ecosystems promoting some insect communities by providing food and nesting resources. 2. This study investigated how host–Natural Enemy communities change in urban and rural landscapes and their transitional zone, the urban–rural interface, by using trap nests for cavity-nesting Hymenoptera in gardens and rapeseed fields that were either isolated or paired in the urban–rural interface. 3. Host dynamics were important for Natural Enemy occurrence, species richness and parasitism rates, and landscape effects were evident for Natural Enemy variables except for the richness of bee Natural enemies. The number of parasitised brood cells was at its highest in the urban–rural interface, but the highest parasitism rates of bees were observed in isolated gardens. Parasitism rates of bees were negatively affected by host abundance, while parasitism rates of wasps were positively affected. 4. Higher specialisation and lower connectivity of host–Natural Enemy interactions were found in paired habitats than in isolated habitats. This indicates that paired habitats comprise more specific Natural enemies and vulnerable interactions, while isolated habitats comprise more generalist Natural enemies, and thus interactions appear more stable. 5. These results confirm that host dynamics play an essential role in the abundance and richness of Natural enemies and drive parasitism. However, high habitat heterogeneity found in the urban–rural interface can also have an effect on host–Natural Enemy communities. This highlights that the provisioning of resources in the urban–rural interface can benefit insect communities in these areas.
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Natural Enemy diversity reduces temporal variability in wasp but not bee parasitism
Oecologia, 2010Co-Authors: Dorthe Veddeler, Jason M Tylianakis, Teja Tscharntke, Alexandra-maria KleinAbstract:Biodiversity may enhance and stabilise ecosystem functioning, but little evidence exists for diversity–function relationships involving multitrophic interactions in real landscapes. In multitrophic communities diversity may vary at different trophic levels, with either synergistic or antagonistic effects on ecosystem functioning. Intensification of land-use systems is often found to reduce diversity, which in turn may lead to reduced associated ecological functions in Natural food webs, such as host-parasite interactions. In this study we investigated the relationship between the number of Natural Enemy and host species and the mean rate and temporal variability of parasitism (inverse of stability), along an intensification gradient of coffee agroforests in Ecuador. We used standardised trap nests for bees and wasps and their Natural enemies in 14 agroforests, and evaluated these monthly over a period of 17 months. We found that parasitism rates of wasps and bees increased with increasing number of Enemy species and decreased with increasing number of host species. Temporal variability in parasitism rates decreased with increasing number of Enemy species and increased with temporal variability in Enemy species richness; however, these effects were restricted to wasp hosts. Intensification of agroforests did not significantly affect species richness of hosts or enemies or their relation to parasitism and its temporal variability. We conclude that high Enemy diversity may enhance parasitism rates and that high host diversity may provide resistance against consumption. Furthermore, we show that a diverse and stable Enemy community may also have a stabilizing effect on parasitism rates. However, these effects may be host-guild specific, as these relations were restricted to wasps.
Douglas A Landis - One of the best experts on this subject based on the ideXlab platform.
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harvesting biofuel grasslands has mixed effects on Natural Enemy communities and no effects on biocontrol services
Journal of Applied Ecology, 2017Co-Authors: Tania N Kim, Douglas A Landis, Aaron F Fox, Bill D Wills, Timothy D Meehan, Claudio GrattonAbstract:Summary Perennial bioenergy systems, such as switchgrass and restored prairies, are alternatives to commonly used annual monocultures such as maize. Perennial systems require lower chemical input, provide greater ecosystem services such as carbon storage, greenhouse gas mitigation and support greater biodiversity of beneficial insects. However, biomass harvest will be necessary in managing these perennial systems for bioenergy production, and it is unclear how repeated harvesting might affect ecosystem services. In this study, we examined how repeated production-scale harvesting of diverse perennial grasslands influences vegetation structure, Natural Enemy communities (arthropod predators and parasitoids), and Natural biocontrol services in two states (Wisconsin and Michigan, USA) over multiple years. We found that repeated biomass harvest reduced litter biomass and increased bare ground cover. Some Natural Enemy groups, such as ground-dwelling arthropods, decreased in abundance with harvest, whereas others such as foliar-dwelling arthropods increased in abundance. The disparity in responses is likely due to how different taxonomic groups utilize vegetation and differences in dispersal abilities. At the community level, biomass harvest altered community composition, increased total arthropod abundance and decreased evenness but did not influence species richness, diversity or biocontrol services. Harvest effects varied with time, diminishing in strength both within the season (for total abundance and evenness), across seasons (for evenness) or were consistent throughout the duration of the study (for community composition). Greater functional redundancy and compensatory responses of the different taxonomic groups may have buffered against the potentially negative effects of harvest on biocontrol services. Synthesis and applications. Our results show that in the short-term, repeated harvesting of perennial grasslands (when insect activity is low) consistently altered vegetation structure but had mixed effects on Natural Enemy communities and no discernible effects on biocontrol services. However, the long-term effects of repeated harvesting on vegetation structure, Natural enemies and other arthropod-derived ecosystem services such as pollination and decomposition remain largely unknown.
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the role of Natural Enemy foraging guilds in controlling cereal aphids in michigan wheat
PLOS ONE, 2014Co-Authors: Shahlo Safarzoda, Christine A Bahlai, Aaron F Fox, Douglas A LandisAbstract:Insect Natural enemies (predators and parasitoids) provide important ecosystem services by suppressing populations of insect pests in many agricultural crops. However, the role of Natural enemies against cereal aphids in Michigan winter wheat (Triticum aestivum L.) is largely unknown. The objectives of this research were to characterize the Natural Enemy community in wheat fields and evaluate the role of different Natural Enemy foraging guilds (foliar-foraging versus ground-dwelling predators) in regulating cereal aphid population growth. We investigated these objectives during the spring and summer of 2012 and 2013 in four winter wheat fields on the Michigan State University campus farm in East Lansing, Michigan. We monitored and measured the impact of Natural enemies by experimentally excluding or allowing their access to wheat plants infested with Rhopalosiphum padi (L.) and Sitobion avenae (F.) (Hemiptera: Aphidae). Our results indicate that the Natural Enemy community in the wheat fields consisted mostly of foliar-foraging and ground-dwelling predators with relatively few parasitoids. In combination, these Natural Enemy groups were very effective at reducing cereal aphid populations. We also investigated the role of each Natural Enemy foraging guild (foliar-foraging versus ground-dwelling predators) independently. Overall, our results suggest that, in combination, Natural enemies can almost completely halt early-season aphid population increase. Independently, ground-dwelling predators were more effective at suppressing cereal aphid populations than foliar-foraging predators under the conditions we studied. Our results differ from studies in Europe and the US Great Plains where foliar foraging predators and parasitoids are frequently more important cereal aphid Natural enemies.
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the role of Natural Enemy guilds in aphis glycines suppression
Biological Control, 2008Co-Authors: Alejandro C Costamagna, Douglas A Landis, Michael J BrewerAbstract:Generalist Natural Enemy guilds are increasingly recognized as important sources of mortality for invasive agricultural pests. However, the net contribution of different species to pest suppression is conditioned by their biology and interspecific interactions. The soybean aphid, Aphis glycines (Hemiptera: Aphididae), is widely attacked by generalist predators, but the relative impacts of different Natural Enemy guilds remains poorly understood. Moreover, low levels of A. glycines parasitism suggest that resident parasitoids may be limited through intraguild predation. During 2004 and 2005, we conducted field experiments to test the impact of different guilds of Natural enemies on A. glycines. We contrasted aphid abundance on field cages with ambient levels of small predators (primarily Orius insidiosus) and parasitoids (primarily Braconidae), sham cages and open controls exposed to large predators (primarily coccinellids), and cages excluding all Natural enemies. We observed strong aphid suppression (86- to 36-fold reduction) in treatments exposed to coccinellids, but only minor reduction due to small predators and parasitoids, with aphids reaching rapidly economic injury levels when coccinellids were excluded. Three species of resident parasitoids were found attacking A. glycines at very low levels (<1% parasitism), with no evidence that intraguild predation by coccinellids attenuated parasitoid impacts. At the plant level, coccinellid impacts resulted in a trophic cascade that restored soybean biomass and yield, whereas small Natural enemies provided only minor protection against yield loss. Our results indicate that within the assemblage of A. glycines Natural enemies in Michigan, coccinellids are critical to maintain aphids below economic injury levels.
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Plant Characteristics Associated with Natural Enemy Abundance at Michigan Native Plants
Environmental entomology, 2007Co-Authors: Anna K. Fiedler, Douglas A LandisAbstract:Habitat management is a type of conservation biological control that focuses on increasing Natural Enemy populations by providing them with plant resources such as pollen and nectar. Insects are known to respond to a variety of plant characteristics in their search for plant-provided resources. A better understanding of the specific characteristics used by Natural Enemy insects in selecting these resources could greatly improve efficiency in screening plants for habitat management. We examined 5 previously tested and widely recommended resource plants and 43 candidate plants to test whether the number and type of Natural enemies and herbivores at each plant were predicted by plant characteristics including: period of peak bloom, floral area, maximum flower height, hue, chroma, and corolla size. Natural Enemy abundance increased with week of peak bloom and greater floral area across all plants tested. Ordination of plant characteristics indicated that increasing floral area, period of peak bloom, maximum flower height, and decreasing corolla width grouped together into a single principal component. Both Natural Enemy and herbivore abundance increased significantly with the principal component for this set of characteristics, but the relationship with herbivore abundance was weaker. These results indicate that, for a given time of the season, selection of plants with the largest floral area has potential to increase Natural Enemy abundance in habitat management plantings and streamline plant selection for habitat management.