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Lennart Persson - One of the best experts on this subject based on the ideXlab platform.

Arne Janssen - One of the best experts on this subject based on the ideXlab platform.

  • Ontogenetic stage-specific reciprocal Intraguild Predation
    Oecologia, 2018
    Co-Authors: Morgana Maria Fonseca, Angelo Pallini, Eraldo Lima, Arne Janssen
    Abstract:

    The size or stage of interacting individuals is known to affect the outcome of ecological interactions and can have important consequences for population dynamics. This is also true for Intraguild Predation (the killing and eating of potential competitors), where the size or ontogenetic stage of an individual determines whether it is the Intraguild predator or the Intraguild prey. Studying size- or stage-specific interactions is therefore important, but can be challenging in species with complex life histories. Here, we investigated predatory interactions of all feeding stages of the two predatory mite species Neoseiulus californicus and Phytoseiulus macropilis , both of which have complex life cycles, typical for predatory arthropods. Populations of these two species compete for two-spotted spider mites, their prey. We evaluated both the capacity to kill stages of the other predator species and the capacity to benefit from feeding on these stages, both prerequisites for the occurrence of Intraguild Predation. Ontogeny played a critical role in the occurrence of Intraguild Predation. Whereas the juveniles of P. macropilis developed from larva until adulthood when feeding on N. californicus eggs, interestingly, adult female P. macropilis did not feed on the smaller stages of the other species. We furthermore show that Intraguild Predation was reciprocal: both juveniles and adult females of N. californicus preyed on the smallest stages of P. macropilis . These results suggest that a proper analysis of the interactions between pairs of species involved in Intraguild Predation should start with an inventory of the interactions among all ontogenetic stages of these species.

  • Reciprocal Intraguild Predation and predator coexistence.
    Ecology and evolution, 2018
    Co-Authors: Renata Vieira Marques, Angelo Pallini, Renato De Almeida Sarmento, Adriana Gonçalves Oliveira, Diego De Macedo Rodrigues, Madelaine Venzon, Marçal Pedro-neto, Arne Janssen
    Abstract:

    Intraguild Predation is a mix of competition and Predation and occurs when one species feeds on another species that uses similar resources. Theory predicts that Intraguild Predation hampers coexistence of species involved, but it is common in nature. It has been suggested that increasing habitat complexity and the presence of alternative food may promote coexistence. Reciprocal Intraguild Predation limits possibilities for coexistence even further. Habitat complexity and the presence of alternative food are believed to promote coexistence. We investigated this using two species of predatory mites, Iphiseiodes zuluagai and Euseius concordis, by assessing co-occurrence in the field and on arenas differing in spatial structure in the laboratory. The predators co-occured on the same plants in the field. In the laboratory, adults of the two mites fed on juveniles of the other species, both in the presence and the absence of a shared food source, showing that the two species are involved in reciprocal Intraguild Predation. Adults of I. zuluagai also attacked adults of E. concordis. This suggests limited possibilities for coexistence of the two species. Indeed, E. concordis invariably went extinct extremely rapidly on arenas without spatial structure with populations consisting of all stages of the two predators and with a shared resource. Coexistence was prolonged on host plant leaves with extra food sources, but E. concordis still went extinct. On small, intact plants, coexistence of the two species was much longer, and ended with the other species, I. zuluagai, often going extinct. These results suggest that spatial structure and the presence of alternative food increase the coexistence period of Intraguild predators.

  • How to evaluate the potential occurrence of Intraguild Predation
    Experimental and Applied Acarology, 2017
    Co-Authors: Morgana Maria Fonseca, Marta Montserrat, Angelo Pallini, Celeste Guzmán, Inmaculada Torres-campos, Arne Janssen
    Abstract:

    Intraguild Predation is the combination of exploitative competition and Predation among potential competitors that use similar resources. It has the potential to shape population dynamics and community structure. Although there is much empirical evidence for the occurrence of Intraguild Predation in natural ecosystems, the study of its effects is mainly limited to short-term microcosm experiments. There is, therefore, certain skepticism about its actual significance in nature. A relevant concern is that there is no consensus regarding criteria to evaluate the possible occurrence of Intraguild Predation in short-term experiments, and methodological differences may therefore underlie apparent inconsistencies among studies. Our purpose here was to evaluate existing criteria to offer guidance for the design of experiments to determine whether two species may potentially engage in Intraguild Predation. The criteria are based on the condition that Intraguild predators need to experience immediate energetic gains when feeding on the Intraguild prey. Thus, a relevant experimental design must quantify Predation but also fitness benefits of feeding on the other species, i.e. increases in reproduction, somatic growth, or survival.

  • Leaf domatia reduce Intraguild Predation among predatory mites
    Ecological Entomology, 2011
    Co-Authors: João A. M. Ferreira, Angelo Pallini, Maurice W. Sabelis, Dalyson F. S. Cunha, Arne Janssen
    Abstract:

    1. Although theory suggests that Intraguild Predation destabilises food webs and may result in exclusion of species, empirical observations of food webs reveal that it is a common interaction. It has been proposed that habitat structure reduces the interaction strength of Intraguild Predation, thus facilitating the coexistence of species. 2. This was tested using acarodomatia, tiny structures on plant leaves, and predatory mites, which usually reside in these domatia. Sweet pepper plants (Capsicum annuum L.) were used, which possess domatia consisting of tufts of hair, and coffee plants (Coffea arabica L.) with pit-shaped domatia. 3. On sweet pepper, the predatory mites Neoseiulus cucumeris Oudemans and Iphiseius degenerans Berl. feed on each other's juveniles. Larvae of each of the species were therefore used as Intraguild prey with adult females of the other species as Intraguild predators. On coffee, a similar set-up was used, with larvae and adult females of Amblyseius herbicolus Chant and Iphiseiodes zuluagai Denmark & Muma as Intraguild prey and Intraguild predators, respectively. 4. Domatia on detached, isolated sweet pepper and coffee leaves were either closed with glue or left open, after which larvae and adult predators were released. As a control, larvae were released on leaves with open or closed domatia without an adult predator. 5. Survival of larvae was high in the absence of the adult (Intraguild) predator. In the presence of the Intraguild predator, survival was significantly higher on leaves with open domatia than on leaves with closed domatia. 6. This shows that even such tiny structures as plant domatia may significantly affect the interaction strength of Intraguild Predation.

  • habitat structure affects Intraguild Predation
    Ecology, 2007
    Co-Authors: Arne Janssen, Marta Montserrat, Sara Magalhães, Maurice W. Sabelis, Tessa Van Der Hammen
    Abstract:

    Intraguild Predation is thought to be ubiquitous in natural food webs. Yet, theory on Intraguild Predation predicts the Intraguild prey to persist only under limited conditions. This gap between theory and empirical observations needs scrutiny. One reason might be that theory has focused on equilibrium dynamics and a limited set of species (usually three) that interact in well-mixed populations in unstructured habitats, and these assumptions will often not hold in natural systems. In this review, we focus on the effects of habitat structure on Intraguild Predation. Habitat structure could reduce encounter rates between predators and prey and could create refuges for prey. In both cases, habitat structure could reduce the strength of Intraguild interactions, thereby facilitating species coexistence. A meta-analysis of studies on manipulation of habitat structure shows that Intraguild prey indeed suffer less from Intraguild Predation in structured habitats. This was further confirmed by a meta-analysis in which studies on Intraguild Predation were classified according to habitat structure. Intraguild Predation reduced densities of the Intraguild prey significantly more in habitats with little structure than in habitats rich in structure. The effect of Intraguild Predation on the shared prey was negative, and not significantly affected by habitat structure. We conclude that habitat structure may increase persistence of the Intraguild prey by decreasing the strength of the interaction between Intraguild predator and Intraguild prey.

André M. De Roos - One of the best experts on this subject based on the ideXlab platform.

  • Exclusive juvenile predator resource promotes coexistence in a size-structured Intraguild Predation system
    2015
    Co-Authors: Birte Reichstein, Lennart Persson, André M. De Roos
    Abstract:

    Coexistence in size-structured Intraguild Predation systems is limited, and is predicted to occur when the IG predator exhibits a complete ontogenetic niche shift, has a similar asymptotic size as ...

  • Habitat complexity does not promote coexistence in a size-structured Intraguild Predation system
    The Journal of animal ecology, 2012
    Co-Authors: Birte Reichstein, Lennart Persson, Arne Schröder, André M. De Roos
    Abstract:

    Size-dependent interactions and habitat complexity have been identified as important factors affecting the persistence of Intraguild Predation (IGP) systems. Habitat complexity has been suggested t ...

  • The role of Predation and competition in a stage-structured Intraguild Predation system
    2010
    Co-Authors: Vincent Hin, André M. De Roos, T. Schellekens, Lennart Persson
    Abstract:

    Omnivorous species can simultaneously prey on and compete with other species, a type of interaction referred to as Intraguild Predation (IGP). Theory predicts that coexistence in IGP systems requir ...

  • Intraguild Predation USUALLY DOES NOT DISRUPT BIOLOGICAL CONTROL
    Progress in Biological Control, 1
    Co-Authors: Arne Janssen, Marta Montserrat, Angelo Pallini, Reinier Hillerislambers, André M. De Roos, Maurice W. Sabelis
    Abstract:

    Intraguild Predation is claimed to be ubiquitous in nature. It also occurs among natural enemies in biological control systems, where one natural enemy (the Intraguild predator) attacks another species of natural enemy (the Intraguild prey), whereas they also compete for the same pest. We review the theory of Intraguild Predation and its consequences for biological control for two different scenarios. 1. The Intraguild predator is the superior natural enemy ($i.e.$ reduces the pest population the most). In this case, the Intraguild predator will exclude the Intraguild prey, thus there will be no Intraguild Predation in the long term. 2. The Intraguild prey is the superior natural enemy. In this case, the Intraguild predator and Intraguild prey may coexist or the Intraguild predator can exclude the Intraguild prey. Theory predicts for this scenario that pest numbers will always be lowest when only the Intraguild prey is present. Hence, the occurrence of Intraguild Predation in cropping systems would never result in increased control, but can result in decreased control. We subsequently review experimental tests of the effect of Intraguild Predation among natural enemies on the population dynamics of pests. Contrary to expectations, we find that Intraguild Predation often did not result in an increase of pest populations, even when the Intraguild predator was the inferior natural enemy. Often, the presence of the Intraguild predator had no effect or even resulted in a decrease of pest populations. Although the number of studies was limited, we scanned the literature to identify possible causes for the discrepancy of experimental results with theoretical predictions. We specifically evaluated trends in the effects with respect to the length of the study period, the spatial scale at which experiments were carried out, the number of species involved in the studies and the spatial complexity of the experimental arenas. There was a slight trend towards experiments of longer duration showing less positive effects on pest densities, but no clear effect of spatial scale. All studies that showed positive effects on pest densities were studies with 3 species, but the number of studies with more than 3 species was small. Spatial complexity had mixed effects on experimental results. In conclusion, it is clear that Intraguild Predation most often does not increase pest densities as was predicted from theory, but more research is needed to reveal why theory does not meet practice.

Birte Reichstein - One of the best experts on this subject based on the ideXlab platform.

Robert F Denno - One of the best experts on this subject based on the ideXlab platform.

  • Spatial refuge from Intraguild Predation: implications for prey suppression and trophic cascades
    Oecologia, 2006
    Co-Authors: Deborah L. Finke, Robert F Denno
    Abstract:

    The ability of predators to elicit a trophic cascade with positive impacts on primary productivity may depend on the complexity of the habitat where the players interact. In structurally-simple habitats, trophic interactions among predators, such as Intraguild Predation, can diminish the cascading effects of a predator community on herbivore suppression and plant biomass. However, complex habitats may provide a spatial refuge for predators from Intraguild Predation, enhance the collective ability of multiple predator species to limit herbivore populations, and thus increase the overall strength of a trophic cascade on plant productivity. Using the community of terrestrial arthropods inhabiting Atlantic coastal salt marshes, this study examined the impact of Predation by an assemblage of predators containing Pardosa wolf spiders, Grammonota web-building spiders, and Tytthus mirid bugs on herbivore populations (Prokelisia planthoppers) and on the biomass of Spartina cordgrass in simple (thatch-free) and complex (thatch-rich) vegetation. We found that complex-structured habitats enhanced planthopper suppression by the predator assemblage because habitats with thatch provided a refuge for predators from Intraguild Predation including cannibalism. The ultimate result of reduced antagonistic interactions among predator species and increased prey suppression was enhanced conductance of predator effects through the food web to positively impact primary producers. Behavioral observations in the laboratory confirmed that Intraguild Predation occurred in the simple, thatch-free habitat, and that the encounter and capture rates of Intraguild prey by Intraguild predators was diminished in the presence of thatch. On the other hand, there was no effect of thatch on the encounter and capture rates of herbivores by predators. The differential impact of thatch on the susceptibility of Intraguild and herbivorous prey resulted in enhanced top-down effects in the thatch-rich habitat. Therefore, changes in habitat complexity can enhance trophic cascades by predator communities and positively impact productivity by moderating negative interactions among predators.

  • interactions between a hunting spider and a web builder consequences of Intraguild Predation and cannibalism for prey suppression
    Ecological Entomology, 2004
    Co-Authors: Robert F Denno, Claudio Gratton, Margaret S Mitter, Gail A Langellotto, Deborah L. Finke
    Abstract:

    Abstract.  1. Antagonistic interactions among invertebrate predators such as Intraguild Predation and cannibalism have the potential to dampen top-down impacts on shared prey at lower trophic levels. Two abundant spider predators, the large wolf spider Pardosa littoralis and the small sheet-web builder Grammonota trivitatta co-occur on the salt marshes of eastern North America where they both attack planthoppers (Prokelisia spp.), the dominant herbivores on the marsh. Experiments both in the laboratory and field were used to assess the incidence of Intraguild Predation and cannibalism in these spiders and elucidate how such antagonistic interactions influence planthopper suppression. 2. Functional response experiments showed that with an increase in planthopper prey density, Grammonota captured more prey but not a higher proportion of that offered. Pardosa exhibited the same response when Grammonota were offered as Intraguild prey. Both functional responses were type I over the range of prey densities offered. 3. Grammonota is moderately cannibalistic, and the presence of planthopper prey reduced the incidence of cannibalism. 4. Factorial experiments in the laboratory showed that Pardosa but not Grammonota reduced planthopper prey populations when prey density was low. By contrast, at high prey densities, both Pardosa and Grammonota had significant adverse effects on planthopper populations. Moreover, there was an interactive effect such that Grammonota reduced planthopper populations relatively more when Pardosa was absent than when it was present. 5. There was direct evidence for the Intraguild Predation of Grammonota by Pardosa such that fewer Grammonota survived in the presence of Pardosa than when it was absent. This result occurred whether planthopper prey were abundant or not. 6. Field releases of Grammonota in open plots resulted in significant but small decreases in the density of planthopper prey, both nymphs and adults. 7. Enhancing densities of Pardosa in open plots resulted in Grammonota suppression. The Intraguild Predation of Grammonota at this enhanced Pardosa density, however, did not preclude Pardosa from significantly reducing planthopper populations. 8. Although there was evidence that Grammonota reduced planthopper populations and that the Intraguild Predation of Grammonota by Pardosa occurred, the strength of these interactions was relatively weak given the low consumption rate of planthoppers by Grammonota (< 3 day–1) and Grammonota by Pardosa (≈ 2 day−1). Thus, weak asymmetric Intraguild Predation among spiders on the marsh likely dampens but does not eliminate the ability of Pardosa to exert significant top-down control on planthopper populations.

  • DOES Intraguild Predation ENHANCE PREDATOR PERFORMANCE? A STOICHIOMETRIC PERSPECTIVE
    Ecology, 2004
    Co-Authors: Masaya Matsumura, Deborah L. Finke, Genevieve M. Trafelet-smith, Claudio Gratton, William F. Fagan, Robert F Denno
    Abstract:

    Ecological stoichiometry provides a novel context for elucidating the occurrence of Intraguild Predation. Recent data show that predators on average have a higher nitrogen content and lower C:N ratio than potential herbivorous prey. Thus, many predators may be nitrogen limited, and Intraguild Predation may allow them to increase their nitrogen intake and growth by supplementing a diet of herbivores with more nitrogen-rich Intraguild prey. We tested this hypothesis using an assemblage of salt-marsh-inhabiting arthropods. First, we determined the nitrogen content and C:N ratio of taxa in four trophic groups (plants, herbivores, omnivores, and predators). Second, we fed an Intraguild predator, the wolf spider Pardosa, one of three diets (herbivores, Intraguild prey, or an alternating mix of the two) and measured spider survival, growth, capture rate, and biomass and nitrogen intake. In general, body nitrogen content increased and C:N ratio decreased from lower to higher trophic levels for marsh-inhabiting sp...

  • Interactions between a hunting spider and a web‐builder: consequences of Intraguild Predation and cannibalism for prey suppression
    Ecological Entomology, 2004
    Co-Authors: Robert F Denno, Claudio Gratton, Margaret S Mitter, Gail A Langellotto, Deborah L. Finke
    Abstract:

    Abstract.  1. Antagonistic interactions among invertebrate predators such as Intraguild Predation and cannibalism have the potential to dampen top-down impacts on shared prey at lower trophic levels. Two abundant spider predators, the large wolf spider Pardosa littoralis and the small sheet-web builder Grammonota trivitatta co-occur on the salt marshes of eastern North America where they both attack planthoppers (Prokelisia spp.), the dominant herbivores on the marsh. Experiments both in the laboratory and field were used to assess the incidence of Intraguild Predation and cannibalism in these spiders and elucidate how such antagonistic interactions influence planthopper suppression. 2. Functional response experiments showed that with an increase in planthopper prey density, Grammonota captured more prey but not a higher proportion of that offered. Pardosa exhibited the same response when Grammonota were offered as Intraguild prey. Both functional responses were type I over the range of prey densities offered. 3. Grammonota is moderately cannibalistic, and the presence of planthopper prey reduced the incidence of cannibalism. 4. Factorial experiments in the laboratory showed that Pardosa but not Grammonota reduced planthopper prey populations when prey density was low. By contrast, at high prey densities, both Pardosa and Grammonota had significant adverse effects on planthopper populations. Moreover, there was an interactive effect such that Grammonota reduced planthopper populations relatively more when Pardosa was absent than when it was present. 5. There was direct evidence for the Intraguild Predation of Grammonota by Pardosa such that fewer Grammonota survived in the presence of Pardosa than when it was absent. This result occurred whether planthopper prey were abundant or not. 6. Field releases of Grammonota in open plots resulted in significant but small decreases in the density of planthopper prey, both nymphs and adults. 7. Enhancing densities of Pardosa in open plots resulted in Grammonota suppression. The Intraguild Predation of Grammonota at this enhanced Pardosa density, however, did not preclude Pardosa from significantly reducing planthopper populations. 8. Although there was evidence that Grammonota reduced planthopper populations and that the Intraguild Predation of Grammonota by Pardosa occurred, the strength of these interactions was relatively weak given the low consumption rate of planthoppers by Grammonota (

  • Intraguild Predation diminish in complex-structured vegetation: Implications for prey supression
    Ecology, 2002
    Co-Authors: Deborah L. Finke, Robert F Denno
    Abstract:

    Multiple-predator limitation of prey populations may be mediated by both predator–predator interactions and vegetation structure. Antagonistic interactions among predators, such as Intraguild Predation, can diminish the collective impact of natural enemies on prey population size. However, structurally complex vegetation may moderate such interactions by providing a refuge for predators, thereby enhancing prey suppression. Spe- cifically, we examined the combined impact of two salt-marsh-inhabiting invertebrate pred- ators, the mirid Tytthus vagus and the wolf spider Pardosa littoralis, on suppression of their shared prey, the planthopper Prokelisia dolus, in simple (thatch-free) and complex (thatch-rich) vegetation. In structurally simple habitats in the laboratory, the predators interacted antagonistically, due to the Intraguild Predation of mirids by spiders, and Predation pressure on the plant- hopper population was relaxed. However, structurally complex habitats dampened this an- tagonistic interaction by providing a refuge for mirids from spider Predation, thereby in- creasing the combined effectiveness of these predators in suppressing planthopper popu- lations. Consistent with our laboratory results, we found enhanced co-occurrence of these predators in complex habitats in the field, where mirids are apparently at lower risk from spider Predation and outbreaks of planthoppers are less likely. In contrast, in simple habitats, mirids were relatively less abundant, a finding consistent with the expectation of increased Intraguild Predation from spiders. Therefore, in this salt marsh system, complex vegetation diminished the occurrence of Intraguild Predation between mirids and spiders and increased overall enemy impact on their shared herbivore prey, demonstrating for the first time that plants can mediate enemy effects on insect herbivores by influencing predator–predator interactions.