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Jaimie T. A. Dick - One of the best experts on this subject based on the ideXlab platform.
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The Effect of the Alternative Prey, Paramecium caudatum (Peniculida: Parameciidae), on the Predation of Culex pipiens (Diptera: Culicidae) by the Copepods Macrocyclops albidus and Megacyclops viridis (Cyclopoida: Cyclopidae).
Journal of medical entomology, 2018Co-Authors: Ross N. Cuthbert, Amanda Callaghan, Jaimie T. A. DickAbstract:Biological control can be an effective tool to combat public health risks associated with mosquito-borne disease. However, target impacts of biological control agents may be reduced by biotic contexts such as the presence of alternative prey. In turn, this can impede our ability to realistically assess biocontrol agent efficacy. Here, we examine the effects of alternative ciliate prey on the predation potential of two Cyclopoid copepods, Macrocyclops albidus Jurine (Cyclopoida: Cyclopidae) and Megacyclops viridis Jurine (Cyclopoida: Cyclopidae), toward larvae of the West Nile virus vector mosquito Culex pipiens Linnaeus (Diptera: Culicidae). Using functional responses (FRs; resource use under different resource densities), we demonstrate that both copepods exhibit potentially destabilizing type II FRs toward mosquito prey. However, where the alternative prey was present, we observed species-specific modulations to FR form and magnitude. For M. albidus, FRs remained type II where ciliate prey were present, however, maximum feeding rates on mosquito larvae were reduced. Conversely, for M. viridis, FRs moved toward more stabilizing type III, while maximum feeding rates on mosquito larvae were not significantly reduced. While both species of Cyclopoid copepod were able to effectively target and consume larval mosquitoes in the presence of alternative prey, we demonstrate that overall efficacies may be reduced in aquatic habitats which contain multiple prey types. We thus advocate that biotic contexts such as prey selectivity should be integrated into predatory biocontrol agent examinations for mosquitoes which vector pathogens and parasites, to more holistically assess their efficacy.
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biological control agent selection under environmental change using functional responses abundances and fecundities the relative control potential rcp metric
Biological Control, 2018Co-Authors: Ross N. Cuthbert, Amanda Callaghan, Jaimie T. A. Dick, James W E DickeyAbstract:Abstract We currently lack the capacity to rapidly and reliably predict the efficacy of biological control agents due to inadequate consistency in derivations of functional and numerical responses and potential effects of context-dependencies. Here, we propose and apply a novel metric, Relative Control Potential (RCP), which combines the functional response (FR, per capita effect) with proxies for the numerical response (NR, agent population response) to compare agent efficacies, where RCP = FR × abundance (or other proxies e.g. fecundity). The RCP metric is a comparative ratio between potential biocontrol agents, where values > 1 indicate higher relative control efficacy. Further, RCP can compare the efficacy of agents under environmental contexts, such as temperature change. We thus derived the RCP for two predatory Cyclopoid copepods, Macrocyclops albidus (Cyclopoida: Cyclopidae) and Megacyclops viridis (Cyclopoida: Cyclopidae), towards larvae of the mosquito Culex pipiens (Diptera: Culicidae) under temperatures representative of current and future climate. Both copepods exhibited potentially population destabilising Type II FRs, with increasing temperatures inducing greater magnitude FRs through increased attack rates and decreased handling times. Attack rates by M. albidus were higher than M. viridis, yet handling times and maximum feeding rates were similar between the species across all temperatures. The inclusion of abundance data drives an elevated RCP of M. albidus and the integration of fecundity drives greater RCP of M. albidus at peak temperatures. Q10 values are indicative of increased feeding activity by both copepods with temperature increases, however relative feeding level increases of M. viridis slowed towards the peak temperature. We present RCP calculations and biplots that represent the comparative efficacies of the two biological control agents across temperatures. The Relative Control Potential (RCP) metric thus provides a new tool for practitioners to better assess the potential efficacy of biocontrol agents before their integration into management approaches for pests, vectors and invasive species.
Rita Adrian - One of the best experts on this subject based on the ideXlab platform.
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calanoid Cyclopoid interactions evidence from an 11 year field study in a eutrophic lake
Freshwater Biology, 1997Co-Authors: Rita AdrianAbstract:1. The interactions between calanoid and Cyclopoid copepods were examined in an 11-year field study of a eutrophic lake (Heiligensee, Berlin, Germany). 2. A diminishing ratio of calanoids to Cyclopoids was observed. The responses, however, were species specific. While two Cyclopoid species responded with increased populations (Cyclops vicinus, Thermocyclops oithonoides), one species exhibited marked declines (C. kolensis). Other species extended the duration of their pelagic phase (Mesocyclops leuckarti, Diacyclops bicuspidatus, T. oithonoides, C. vicinus), leading to higher population overlaps. Eudiaptomus graciloides and E. gracilis, which used to be present throughout the year, were more frequently absent. 3. These changes coincided with a series of mild winters during which prey availability (algae and rotifers) was high. 4. Enhanced prey availability, in conjunction with a flexible diapausing strategy, are hypothesized to underly the increased success of C. vicinus. Predatory losses due to early occurrence and enhanced abundances of C. vicinus, rather than competition for the same food resources, are hypothesized to be responsible for the declines of C. kolensis and Eudiaptomus. 5. Summer species tended to develop higher abundances early in the season, which led to enhanced seasonal means during spring. These changes cannot be explained by the interaction between calanoids and Cyclopoids alone, but were probably a result of changes in fish predation.
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Calanoid–Cyclopoid interactions: evidence from an 11‐year field study in a eutrophic lake
Freshwater Biology, 1997Co-Authors: Rita AdrianAbstract:1. The interactions between calanoid and Cyclopoid copepods were examined in an 11-year field study of a eutrophic lake (Heiligensee, Berlin, Germany). 2. A diminishing ratio of calanoids to Cyclopoids was observed. The responses, however, were species specific. While two Cyclopoid species responded with increased populations (Cyclops vicinus, Thermocyclops oithonoides), one species exhibited marked declines (C. kolensis). Other species extended the duration of their pelagic phase (Mesocyclops leuckarti, Diacyclops bicuspidatus, T. oithonoides, C. vicinus), leading to higher population overlaps. Eudiaptomus graciloides and E. gracilis, which used to be present throughout the year, were more frequently absent. 3. These changes coincided with a series of mild winters during which prey availability (algae and rotifers) was high. 4. Enhanced prey availability, in conjunction with a flexible diapausing strategy, are hypothesized to underly the increased success of C. vicinus. Predatory losses due to early occurrence and enhanced abundances of C. vicinus, rather than competition for the same food resources, are hypothesized to be responsible for the declines of C. kolensis and Eudiaptomus. 5. Summer species tended to develop higher abundances early in the season, which led to enhanced seasonal means during spring. These changes cannot be explained by the interaction between calanoids and Cyclopoids alone, but were probably a result of changes in fish predation.
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Filtering and feeding rates of Cyclopoid copepods feeding on phytoplankton
Hydrobiologia, 1991Co-Authors: Rita AdrianAbstract:The algal biomass ingested by omnivorous Cyclopoid copepods (Cyclops kolensis and C. vicinus) was measured by two methods in the hypertrophic Heiligensee in Berlin (West Germany). The clearance and ingestion rates inferred from measurements of natural populations of 14C labelled phytoplankton were compared with those obtained from chlorophyll a determinations using the presence/absence method (observed chlorophyll a content of natural lake phytoplankton with and without addition of Cyclopoids). Both methods gave similar results. Nevertheless, the radio tracer method is preferred, mainly because the short feeding duration excludes high variations in both the food composition and food concentration that limit the presence/absence method.
Ross N. Cuthbert - One of the best experts on this subject based on the ideXlab platform.
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The Effect of the Alternative Prey, Paramecium caudatum (Peniculida: Parameciidae), on the Predation of Culex pipiens (Diptera: Culicidae) by the Copepods Macrocyclops albidus and Megacyclops viridis (Cyclopoida: Cyclopidae).
Journal of medical entomology, 2018Co-Authors: Ross N. Cuthbert, Amanda Callaghan, Jaimie T. A. DickAbstract:Biological control can be an effective tool to combat public health risks associated with mosquito-borne disease. However, target impacts of biological control agents may be reduced by biotic contexts such as the presence of alternative prey. In turn, this can impede our ability to realistically assess biocontrol agent efficacy. Here, we examine the effects of alternative ciliate prey on the predation potential of two Cyclopoid copepods, Macrocyclops albidus Jurine (Cyclopoida: Cyclopidae) and Megacyclops viridis Jurine (Cyclopoida: Cyclopidae), toward larvae of the West Nile virus vector mosquito Culex pipiens Linnaeus (Diptera: Culicidae). Using functional responses (FRs; resource use under different resource densities), we demonstrate that both copepods exhibit potentially destabilizing type II FRs toward mosquito prey. However, where the alternative prey was present, we observed species-specific modulations to FR form and magnitude. For M. albidus, FRs remained type II where ciliate prey were present, however, maximum feeding rates on mosquito larvae were reduced. Conversely, for M. viridis, FRs moved toward more stabilizing type III, while maximum feeding rates on mosquito larvae were not significantly reduced. While both species of Cyclopoid copepod were able to effectively target and consume larval mosquitoes in the presence of alternative prey, we demonstrate that overall efficacies may be reduced in aquatic habitats which contain multiple prey types. We thus advocate that biotic contexts such as prey selectivity should be integrated into predatory biocontrol agent examinations for mosquitoes which vector pathogens and parasites, to more holistically assess their efficacy.
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biological control agent selection under environmental change using functional responses abundances and fecundities the relative control potential rcp metric
Biological Control, 2018Co-Authors: Ross N. Cuthbert, Amanda Callaghan, Jaimie T. A. Dick, James W E DickeyAbstract:Abstract We currently lack the capacity to rapidly and reliably predict the efficacy of biological control agents due to inadequate consistency in derivations of functional and numerical responses and potential effects of context-dependencies. Here, we propose and apply a novel metric, Relative Control Potential (RCP), which combines the functional response (FR, per capita effect) with proxies for the numerical response (NR, agent population response) to compare agent efficacies, where RCP = FR × abundance (or other proxies e.g. fecundity). The RCP metric is a comparative ratio between potential biocontrol agents, where values > 1 indicate higher relative control efficacy. Further, RCP can compare the efficacy of agents under environmental contexts, such as temperature change. We thus derived the RCP for two predatory Cyclopoid copepods, Macrocyclops albidus (Cyclopoida: Cyclopidae) and Megacyclops viridis (Cyclopoida: Cyclopidae), towards larvae of the mosquito Culex pipiens (Diptera: Culicidae) under temperatures representative of current and future climate. Both copepods exhibited potentially population destabilising Type II FRs, with increasing temperatures inducing greater magnitude FRs through increased attack rates and decreased handling times. Attack rates by M. albidus were higher than M. viridis, yet handling times and maximum feeding rates were similar between the species across all temperatures. The inclusion of abundance data drives an elevated RCP of M. albidus and the integration of fecundity drives greater RCP of M. albidus at peak temperatures. Q10 values are indicative of increased feeding activity by both copepods with temperature increases, however relative feeding level increases of M. viridis slowed towards the peak temperature. We present RCP calculations and biplots that represent the comparative efficacies of the two biological control agents across temperatures. The Relative Control Potential (RCP) metric thus provides a new tool for practitioners to better assess the potential efficacy of biocontrol agents before their integration into management approaches for pests, vectors and invasive species.
Winfried Lampert - One of the best experts on this subject based on the ideXlab platform.
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subitaneous eggs of freshwater copepods pass through fish guts survival hatchability and potential ecological implications
Limnology and Oceanography, 2005Co-Authors: Silvia Bartholme, Laryssa Samchyshyna, Barbara Santer, Winfried LampertAbstract:We measured the survival of subitaneous eggs of two calanoid (Eudiaptomus gracilis, E. graciloides ) and two Cyclopoid (Cyclops abyssorum, Macrocyclops albidus ) freshwater copepods after they had been consumed by fish. Unexpectedly, over 80% of the calanoid eggs and 30‐59% of the Cyclopoid eggs were morphologically intact in fish feces. Subitaneous eggs of E. graciloides showed similar proportions of gut passage as dormant resting eggs. About 70‐80% of the calanoid eggs and 35‐50% of the Cyclopoid eggs released nauplii within 3 d. Hence, a total of 50‐70% of the calanoid eggs and 11‐29% of the Cyclopoid eggs survived ingestion and gut passage. Survival was slightly higher because of shorter gut passage time when the fish had been prefed natural plankton compared with hungry fish. We interpret digestion resistance of subitaneous eggs in copepods as an adaptation to fish predation on egg-carrying females.
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Summer diapause in Cyclopoid copepods: adaptive response to a food bottleneck?
The Journal of Animal Ecology, 1995Co-Authors: Barbara Santer, Winfried LampertAbstract:Summer diapause in freshwater Cyclopoid copepods is often regarded as an adaptation to avoid fish predation. We tested the alternative hypothesis that the ultimate reason for fourth instar copepodites to enter the sediment during summer is to avoid a food bottleneck for herbivorous juvenile stages caused by the grazing of competing cladocerans. Seasonal life cycles of three co-existing Cyclopoid copepod species, Cyclops kolensis, C. vicinus and C. abyssorum, which spend the summer in anoxic sediments, were studied in a eutrophic lake. All three species undergo an ontogenetic shift in their feeding habits from herbivory in the naupliar stages to omnivory in the later juvenile and adult stages. Nauplii depend on flagellates as food. Copepods were cultured in the laboratory without a diapause. Nauplii were subjected to lake water containing seston that was freshly collected during the different seasons, and their growth and development was recorded. Nauplii developed quickly into copepodites in lake water that was drawn in late winter (February/March), when they were abundant in the lake. In late spring and early summer, when cladocerans dominated the plankton, lake water did not support naupliar growth. Development of C. abyssorum was retarded and nauplii from the other two species died before they reached the first copepodite stage. However, all species developed nearly optimally during spring and summer if the water was supplemented with flagellates. We conclude that all species must pass a serious bottleneck as they need high concentrations of flagellates for their naupliar development. Hence, summer diapause may be an adaptation to avoid poor food conditions for nauplii. Fish predation may be important for shaping the timing of diapause in C. abyssorum, as this is the largest species and is least affected by food limitation. This hypothesis is supported by a comparison of diapause behaviour of Cyclopoids in lakes of varying trophy.
Fernandez-leborans Gregorio - One of the best experts on this subject based on the ideXlab platform.
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Occurrence of Epistylis anastatica (Linnaeus, 1767) (Ciliophora: Peritrichia) on Mesocyclops isabellae Dussart & Fernando (Crustacea: Copepoda: Cyclopoida) in India, with an annotated checklist of species of Epistylis reported as Epibionts of Cyclopo
2016Co-Authors: Clamp, John C., Chatterjee Tapas, Fernandez-leborans GregorioAbstract:Clamp, John C., Chatterjee, Tapas, Fernandez-Leborans, Gregorio (2016): Occurrence of Epistylis anastatica (Linnaeus, 1767) (Ciliophora: Peritrichia) on Mesocyclops isabellae Dussart & Fernando (Crustacea: Copepoda: Cyclopoida) in India, with an annotated checklist of species of Epistylis reported as Epibionts of Cyclopoid Copepods and resources for their identification. Zootaxa 4168 (3): 525-540, DOI: http://doi.org/10.11646/zootaxa.4168.3.
