Occurrence Of Intraguild Predation Research Articles

Diet type and prey preference of predators affect intraguild predation between Amblyseius andersoni and Neoseiulus barkeri

Amblyseius andersoni and Neoseiulus barkeri, two species of phytoseiid mites that are widely used for the control of small sucking pests, were found to co-occur on Chinese wolfberry in Inner Mongolia. We investigated the possibility of intraguild predation (IGP) between A. andersoni and N. barkeri to explore the interactions and coexistence of these two species. Predation and oviposition of the two predators on heterospecific juveniles were measured and compared with Tetranychus truncatus or Typha pollen as food, or without alternative food. The mortality rate of N. barkeri juveniles was not affected by the diet treatment, but that of A. andersoni juveniles was reduced by the presence of spider mites. The presence of spider mites also increased oviposition by A. andersoni but not by N. barkeri, and the presence of pollen had no influence on the oviposition of the two predators. Thus, according to the IGP criteria for gaining benefits from predation on heterospecific juveniles, it was concluded that IGP between A. andersoni and N. barkeri occurred, with A. andersoni as intraguild predator and N. barkeri as intraguild prey when spider mites were present. In a further choice test in which heterospecific juveniles and T. truncatus juveniles were provided for each predator, female A. andersoni preferred to prey on N. barkeri rather than on spider mites, whereas female N. barkeri preferred to feed on spider mites rather than on A. andersoni. These findings indicate that the higher preference of N. barkeri on T. truncatus might result in its lower predation on the other predator species compared with A. andersoni and, thus, increased the possibility of the coexistence of the two predator species. Therefore, the occurrence of IGP between A. andersoni and N. barkeri appears to be influenced by the availability and type of the diet and the prey preference of the predators.

Effect of ant-attendance on the occurrence of intraguild predation

Parasitoids and predators exploiting similar food resource make aphidophagous guilds especially favourable systems for studying intraguild predation, but ants as third parties protect aphids against their natural enemies and in return obtain carbohydrate-rich honeydew as a nutritional resource. A field experiment on the interrelationship among aphids, ants and predators/parasitoids was conducted on two plants (hoary cress Cardaria draba L. [Brassicaceae) and Canada thistle Cirsium arvense L. [Asteraceae]). Cardaria was infested with the aphid Acyrthosiphon gossypii Mordvilko (Homoptera: Aphididae) tended by the ant Lasius turcicus Santschi (Hymenoptera: Formicidae). Cirsium was infested with the aphid Brachycaudus cardui L. (Homoptera: Aphididae) tended by the ant Crematogaster sordidula Nylander (Hymenoptera: Formicidae). The mean number of predators per aphid colony decreased significantly when the aphids were tended by ants on both host plants. In contrast, the parasitism rate of both aphids decreased significantly without the tending ant. Thus ant attendance can affect the occurrence and intensity of intraguild predation, and consequently provide enemy free space for parasitoids. If a foraging female aphid parasitoid succeeds in ovipositing into patches with guarding ants, then its offspring could be protected from the risk of intraguild predation.

Can the Combined Use of the Mirid Predator Nesidiocoris tenuis and a Braconid Larval Endoparasitoid Dolichogenidea gelechiidivoris Improve the Biological Control of Tuta absoluta?

Simple SummaryCombining natural enemies may lead to synergistic, additive, or antagonistic effects on the control of insect pests. An investigation into the nature and outcome of the interaction between a generalist mirid predator, Nesidiocoris tenuis, and a specialist koinobiont larval endoparasitoid, Dolichogenidea gelechiidivoris, in the control of a co-shared host/prey, Tuta absoluta, was undertaken under laboratory conditions. We found that the presence of N. tenuis did not affect oviposition performance or progeny production by D. gelechiidivoris. When both natural enemies were combined, the efficacy in reducing T. absoluta populations was significantly higher than that of either natural enemy used alone. Nesidiocoris tenuis preferentially reduced the densities of T. absoluta eggs, while D. gelechiidivoris reduced the larval stages of the pest. The combined use of N. tenuis and D. gelechiidivoris could potentially help reduce the overall infestation level of T. absoluta in tomato agroecosystems.The koinobiont solitary larval endoparasitoid Dolichogenidea gelechiidivoris (Marsh) (Syn.: Apanteles gelechiidivoris) (Hymenoptera: Braconidae) and the predatory bug Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae) are important natural enemies of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), a serious pest of tomato. Although N. tenuis preferentially feeds on T. absoluta eggs, it is also recorded as a predator of first and second instar larval stages. Dolichogenidea gelechiidivoris preferentially seeks these early larval stages of T. absoluta for oviposition. The occurrence of intraguild predation between N. tenuis and D. gelechiidivoris and the consequences on the oviposition performance of D. gelechiidivoris were investigated in the laboratory. Regardless of the manner of introduction (i.e., the sequence of combinations with D. gelechiidivoris) or density (i.e., number of N. tenuis combined with D. gelechiidivoris), the presence of N. tenuis did not affect the oviposition performance of D. gelechiidivoris or the parasitoid’s progeny. Combination assays revealed that the efficacy of the combined use of N. tenuis and D. gelechiidivoris in controlling T. absoluta populations was significantly higher than that of either natural enemy alone. Our results highlight the potential of combining mirid predators and koinobiont larval endoparasitoids to control T. absoluta. The findings further contribute to data supporting the release of D. gelechiidivoris in tomato agroecosystems for the control of T. absoluta in Africa, where N. tenuis is widespread and abundant.

Intraguild Predation between Chrysoperla carnea (Neuroptera: Chrysopidae) and Hippodamia variegata (Coleoptera: Coccinellidae) at Various Extraguild Prey Densities and Arena Complexities.

Intraguild predation (IGP) is a ubiquitous, important and common interaction that occurs in aphidophagous guilds. The effects of extraguild prey (EGP, i.e., aphids) density, predator life stage combinations and duration of the interaction on the level, asymmetry and direction of intraguild predation between lacewing Chrysoperla carnea and ladybird Hippodamia variegata were examined in simple laboratory arena and more complex microcosm environment. Three initial densities of 50, 150 and 400 Aphis fabae third instar nymphs and a control without aphids were provided to six combinations of predator life stages (2nd and 3rd larval instars of lacewing and 3rd and 4th instars and adult females of ladybird). The remaining aphid density and occurrence of IGP were checked after 24, 48 and 72 h. The IGP intensity (IGP level, IL) was similar in the simple arena (reaching 0.6 between larvae in absence of EGP and 0.3 between lacewing larvae and ladybird females) and microcosm environment (0.3 without EGP). In both environments, increasing EGP density lowered IL according to negative exponential relationship. IGP was asymmetric (general average asymmetry was 0.82 in simple arena and 0.93 in microcosm, the difference was not significant) and mostly in favour of larvae of C. carnea, except in the combination of 2nd larvae of C. carnea with the 4th larvae and adults of H. variegata. The direction of IGP, but not other characteristics, partially changed during the duration of the experiment. The incidence of IGP interactions among aphid predators under real conditions and its consequences on aphid biological control are discussed.

Ontogenetic stage-specific reciprocal intraguild predation

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.

The impact of ant attendance on protecting Aphis gossypii against two aphidophagous predators and it’s role on the Intraguild Predation between them

In this study the changes in Aphis gossypii Glover populations tended by the homopteran- tending ant, Tapinoma simrothi Krausse when exposed to the natural enemies Chrysoperla carnea Stephens and Coccinellia septempunctata Mulsant was studied. We also studied the effect of ant’s attendance on the consequence of intraguild predation (IGP) between these two predators. The presence of ants T. simrothi had deterrent impact on natural enemies of A. gossypii compared to control aphid populations in absence of ants. Equally we observed that IGP between two aphid predators decreased when T. simrothi was present. The lowest IGP level was observed when both aphids and ants were present in the microcosm arena. In the microcosm arena the presence of ants had an indirect effect on the occurrence of IGP. Our results suggest that although the mutualistic ants have an indirect impact on the IGP by aphidophages predators, but their roles should not be ignored.

How to evaluate the potential occurrence of intraguild predation

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.

Interspecific and geographic variation in the diets of sympatric carnivores: dingoes/wild dogs and red foxes in south-eastern Australia.

Dingoes/wild dogs (Canis dingo/familiaris) and red foxes (Vulpes vulpes) are widespread carnivores in southern Australia and are controlled to reduce predation on domestic livestock and native fauna. We used the occurrence of food items in 5875 dingo/wild dog scats and 11,569 fox scats to evaluate interspecific and geographic differences in the diets of these species within nine regions of Victoria, south-eastern Australia. The nine regions encompass a wide variety of ecosystems. Diet overlap between dingoes/wild dogs and foxes varied among regions, from low to near complete overlap. The diet of foxes was broader than dingoes/wild dogs in all but three regions, with the former usually containing more insects, reptiles and plant material. By contrast, dingoes/wild dogs more regularly consumed larger mammals, supporting the hypothesis that niche partitioning occurs on the basis of mammalian prey size. The key mammalian food items for dingoes/wild dogs across all regions were black wallaby (Wallabia bicolor), brushtail possum species (Trichosurus spp.), common wombat (Vombatus ursinus), sambar deer (Rusa unicolor), cattle (Bos taurus) and European rabbit (Oryctolagus cuniculus). The key mammalian food items for foxes across all regions were European rabbit, sheep (Ovis aries) and house mouse (Mus musculus). Foxes consumed 6.1 times the number of individuals of threatened Critical Weight Range native mammal species than did dingoes/wild dogs. The occurrence of intraguild predation was asymmetrical; dingoes/wild dogs consumed greater biomass of the smaller fox. The substantial geographic variation in diet indicates that dingoes/wild dogs and foxes alter their diet in accordance with changing food availability. We provide checklists of taxa recorded in the diets of dingoes/wild dogs and foxes as a resource for managers and researchers wishing to understand the potential impacts of policy and management decisions on dingoes/wild dogs, foxes and the food resources they interact with.

Impact of plant architecture and extraguild prey density on intraguild predation in an agroecosystem

Several models and experimental studies conducted in confined environments have shown that intraguild predation (IGP) can modulate population abundances and structure communities. A number of ecological and abiotic factors determine the nature and frequency of IGP. This study examined the effect of plant architecture and extraguild prey density, and their interactions, on the occurrence of IGP between two species of ladybird, Harmonia axyridis (Pallas) and Propylea quatuordecimpunctata L. (both Coleoptera: Coccinellidae). Theoretical concepts predict that IGP levels would increase with a decrease of both extraguild prey density and plant structural complexity. We conducted a factorial experiment in an open soybean field into which coccinellid larvae were introduced in experimental plots for a period of 5 days. We tested two levels of soybean aphid [Aphis glycines Matsumara (Hemiptera: Aphididae)] density, low and high (100 and 1 000 aphids per plot, respectively), and two levels of plant complexity, low (by removing half of the branches from the soybean plants) and high (by leaving plants intact). We used species-specific molecular markers to detect the presence of P. quatuordecimpunctata in the digestive tract of H. axyridis. Molecular gut-content analysis of H. axyridis revealed that rates of IGP were higher (20%) at low aphid density than at high aphid density (<6%). Decreased plant complexity did not impact the frequency of IGP. In accordance with existing literature, this study demonstrates that IGP is amplified at low extraguild prey density. We conclude that considering environmental factors, such as extraguild prey density, is crucial to improve our ability to predict the impact of intraguild predation on community structure and, from an applied perspective, biological control.

Aspectos biológicos de Harmonia axyridis alimentada com duas espécies de presas e predação intraguilda com Eriopis connexa

O objetivo deste trabalho foi determinar os aspectos biológicos de Harmonia axyridis, alimentada com duas espécies de presas, e a ocorrência de predação intraguilda com Eriopis connexa. Larvas de H. axyridis foram alimentadas diariamente com ovos de Anagasta kuehniella ou com o pulgão Schizaphis graminum. Adultos da joaninha foram separados em dez casais que receberam o mesmo tipo de alimento da fase larval. Na avaliação da predação, uma larva de quarto instar de cada espécie foi mantida na presença ou ausência de abrigo e de ovos de A. kuehniella. A fase larval de H. axyridis durou 10,2 e 8,9 dias, quando alimentada com A. kuehniella e S. graminum, respectivamente. A sobrevivência do predador, em fase imatura, variou de 70 a 100%. A joaninha apresentou período de oviposição de 47,3 e 51,7 dias, com 887,6 e 822,5 ovos, ao se alimentar de A. kuehniella e S. graminum, respectivamente. A longevidade das fêmeas foi de 74,1 e 76,2 dias e a dos machos de 67,3 e 70,3 dias, em A. kuehniella e S. graminum, respectivamente. H. axyridis atuou como predador intraguilda e foi a espécie dominante na competição com E. connexa.

Stable isotope analyses document intraguild predation in wolf spiders (Araneae: Lycosidae) and underline beneficial effects of alternative prey and microhabitat structure on intraguild prey survival

Intraguild predation (IGP) is common among generalist predators and an important issue in food web theory, because IGP may destabilise communities by increasing extinction of species. Also, IGP may interfere with the effectiveness of generalist predators as biological control agents. In general, occurrence of IGP in laboratory or field studies is inferred from abundance data or direct observations only. We investigated if tracing stable isotopes allows distinction between different types of predation and confirmation of IGP. Wolf spiders were chosen as model organisms for generalist predators; IGP of third instarA. cuneataon second instarP. palustriswas investigated in a laboratory experiment. The availability of alternative prey and the complexity of the microhabitat were manipulated, since both factors are thought to facilitate coexistence of predators.Stable isotope analysis documented predation ofA. cuneataonP. palustrisand predation on alternative prey by both juveniles. Both the presence of alternative prey and the availability of shelter reduced mortality of juvenileP. palustrisduring the first week. During the second week mortality increased in complex structure without alternative prey presumably due to enhanced activity and cannibalism among starvingP. palustris. Thus, microhabitat complexity and prey abundance may foster coexistence of wolf spiders in the field.In conclusion, stable isotope analysis was proven a powerful tool to investigate animal behaviour without direct observation. The method allowed disentangling predator feeding behaviour when more than one type of prey was present.