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Paulo S. Oliveira - One of the best experts on this subject based on the ideXlab platform.
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Indirect effects of mutualism: ant–Treehopper associations deter pollinators and reduce reproduction in a tropical shrub
Oecologia, 2018Co-Authors: Javier Ibarra-isassi, Paulo S. OliveiraAbstract:Animal-pollinated plants can be susceptible to changes in pollinator availability. Honeydew-producing Treehoppers frequently occur on inflorescences, potentially enhancing ant-mediated negative effects on pollination services. However, the effect of ant-attended, honeydew-producing insects on plant reproduction remains uncertain. We recorded the abundance of Treehoppers and ants on Byrsonima intermedia (Malpighiaceae), and monitored floral visitors in a Brazilian cerrado savanna. We manipulated the presence of ants and ant–Treehopper associations on inflorescences to assess their effect on pollination and fruit formation. We used dried ants pinned to inflorescences to evaluate the effect of ant presence and ant identity on potential pollinators. Results show that the presence of Treehoppers increases ant abundance on flowers and disrupts pollination by oil-collecting bees, decreasing the frequency and duration of floral visits and reducing fruit and seed set. Treehopper herbivory has no direct effect on fruit or seed production, which are independent of Treehopper density. Pinned ants promote avoidance by floral visitors, reducing the number of visits. Ant identity mediates visitation decisions, with Ectatomma brunneum causing greater avoidance by floral visitors than Camponotus rufipes . Field videos show that pollinating bees are harassed by ants near flowers, prompting avoidance behavior by the bees. This is the first demonstration of indirect effects by honeydew-gathering ants, via disrupted pollination, on plant reproduction in tropical cerrado savanna. Our results highlight the importance of studying other interactions near flowers, in addition to just observing pollinators, for a proper understanding of plant reproduction.
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Indirect effects of mutualism: ant-Treehopper associations deter pollinators and reduce reproduction in a tropical shrub.
Oecologia, 2017Co-Authors: Javier Ibarra-isassi, Paulo S. OliveiraAbstract:Animal-pollinated plants can be susceptible to changes in pollinator availability. Honeydew-producing Treehoppers frequently occur on inflorescences, potentially enhancing ant-mediated negative effects on pollination services. However, the effect of ant-attended, honeydew-producing insects on plant reproduction remains uncertain. We recorded the abundance of Treehoppers and ants on Byrsonima intermedia (Malpighiaceae), and monitored floral visitors in a Brazilian cerrado savanna. We manipulated the presence of ants and ant–Treehopper associations on inflorescences to assess their effect on pollination and fruit formation. We used dried ants pinned to inflorescences to evaluate the effect of ant presence and ant identity on potential pollinators. Results show that the presence of Treehoppers increases ant abundance on flowers and disrupts pollination by oil-collecting bees, decreasing the frequency and duration of floral visits and reducing fruit and seed set. Treehopper herbivory has no direct effect on fruit or seed production, which are independent of Treehopper density. Pinned ants promote avoidance by floral visitors, reducing the number of visits. Ant identity mediates visitation decisions, with Ectatomma brunneum causing greater avoidance by floral visitors than Camponotus rufipes. Field videos show that pollinating bees are harassed by ants near flowers, prompting avoidance behavior by the bees. This is the first demonstration of indirect effects by honeydew-gathering ants, via disrupted pollination, on plant reproduction in tropical cerrado savanna. Our results highlight the importance of studying other interactions near flowers, in addition to just observing pollinators, for a proper understanding of plant reproduction.
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myrmecophilous butterflies utilise ant Treehopper associations as visual cues for oviposition
Ecological Entomology, 2016Co-Authors: Luísa L. Mota, Paulo S. OliveiraAbstract:1. Selection of a safe oviposition site is important for herbivorous insects whose immature stages have limited mobility. Female herbivores rely on environmental cues for this choice, and presence of natural enemies or mutualistic partners may be important in this process. 2. Some butterflies have mutualistic interactions with ants (myrmecophily), in which caterpillars offer a nutritional liquid and gain protection against natural enemies. Participants in butterfly–ant mutualisms may utilise signals to initiate interactions, but the use of visual cues by ovipositing myrmecophilous butterflies remains uncertain. 3. Larvae of facultatively myrmecophilous Parrhasius polibetes (Lycaenidae) feed on Schefflera vinosa, and females prefer to oviposit near aggregations of the ant-tended Treehopper Guayaquila xiphias, where caterpillars survive better due to increased ant attendance. Given the conspicuousness of ant–Treehopper associations, it was investigated whether butterflies use them as visual cues for oviposition and, if so, which participants of the association are used as cues: ants, Treehoppers, or both. 4. Experiments using dried insects on paired branches revealed that females visually recognise ants and ant–Treehopper associations, using them for egg-laying decisions. However, presence of a Treehopper aggregation alone had no effect on oviposition choices. 5. This is a first insight into the importance of visual discrimination for ovipositing myrmecophilous butterflies. The results show that facultative mutualisms can be important enough to promote a behavioural adaptation (visual detection of ants) reinforcing the interaction. Our research highlights the importance of the behavioural interface within complex multispecies systems.
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Myrmecophilous butterflies utilise ant–Treehopper associations as visual cues for oviposition
Ecological Entomology, 2016Co-Authors: Luísa L. Mota, Paulo S. OliveiraAbstract:1. Selection of a safe oviposition site is important for herbivorous insects whose immature stages have limited mobility. Female herbivores rely on environmental cues for this choice, and presence of natural enemies or mutualistic partners may be important in this process. 2. Some butterflies have mutualistic interactions with ants (myrmecophily), in which caterpillars offer a nutritional liquid and gain protection against natural enemies. Participants in butterfly–ant mutualisms may utilise signals to initiate interactions, but the use of visual cues by ovipositing myrmecophilous butterflies remains uncertain. 3. Larvae of facultatively myrmecophilous Parrhasius polibetes (Lycaenidae) feed on Schefflera vinosa, and females prefer to oviposit near aggregations of the ant-tended Treehopper Guayaquila xiphias, where caterpillars survive better due to increased ant attendance. Given the conspicuousness of ant–Treehopper associations, it was investigated whether butterflies use them as visual cues for oviposition and, if so, which participants of the association are used as cues: ants, Treehoppers, or both. 4. Experiments using dried insects on paired branches revealed that females visually recognise ants and ant–Treehopper associations, using them for egg-laying decisions. However, presence of a Treehopper aggregation alone had no effect on oviposition choices. 5. This is a first insight into the importance of visual discrimination for ovipositing myrmecophilous butterflies. The results show that facultative mutualisms can be important enough to promote a behavioural adaptation (visual detection of ants) reinforcing the interaction. Our research highlights the importance of the behavioural interface within complex multispecies systems.
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trade offs underlying polyphagy in a facultative ant tended florivorous butterfly the role of host plant quality and enemy free space
Oecologia, 2010Co-Authors: Daniela Rodrigues, André V. L. Freitas, Lucas A. Kaminski, Paulo S. OliveiraAbstract:The underlying mechanisms mediating the use of multiple host plants were investigated in Parrhasius polibetes (Lycaenidae), a florivorous and facultative myrmecophilous butterfly. Plant traits such as presence of ant–Treehopper associations as a source of enemy-free space, flower bud dimensions, toughness, thickness, trichomes, and the corresponding performance and wear of P. polibetes mandibles were examined for three natural hosts: Schefflera vinosa (Araliaceae), Pyrostegia venusta (Bignoniaceae) and Luehea grandiflora (Malvaceae). Parasitism levels of larvae found on the three hosts were also determined. Almost all Luehea had ant–Treehopper associations, and all larvae found on this host were non-parasitized. Parasitism was low in larvae found on Schefflera, half of which hosted ant–Treehopper associations. No ant–Treehopper association was found on Pyrostegia, where parasitism was significantly higher compared to other hosts. In the laboratory, P. polibetes performed well on Schefflera, followed by Pyrostegia. No larvae survived when fed with Luehea. Flower buds of Luehea were thicker and tougher than those of Schefflera and Pyrostegia. Indeed, mandibles of larvae reared on Luehea showed substantial wear, whereas those reared either on Schefflera or Pyrostegia presented no significant damage. Additionally, we suggest that co-occurrence with ant–Treehopper associations on a plant provides parasitoid-free space for P. polibetes larvae. Our results support the hypothesis that ecological trade-offs among host plants (i.e., food quality and enemy-free space) promote polyphagy in natural populations of P. polibetes. Host morphological traits seem to play a relevant role in P. polibetes performance. To our knowledge, this is the first report showing the costs of polyphagy in a myrmecophilous butterfly.
Kleber Del-claro - One of the best experts on this subject based on the ideXlab platform.
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Conditional outcomes in a neotropical Treehopper-ant association: temporal and species-specific variation in ant protection and homopteran fecundity.
Oecologia, 2000Co-Authors: Kleber Del-claro, Paulo S. OliveiraAbstract:We studied the association between the honeydew-producing membracid Guayaquila xiphias and its tending ants in the cerrado savanna of Brazil, during 1992 and 1993. Results showed that ants attack potential enemies of G. xiphias, and that increased ant density near the Treehoppers affects the spatial distribution of parasitoid wasps on the host plant, keeping them away from brood-guarding G. xiphias females. Controlled ant-exclusion experiments revealed that ant presence (seven species) reduces the abundance of G. xiphias’ natural enemies (salticid spiders, syrphid flies, and parasitoid wasps) on the host plant. The data further showed that ant-tending not only increased homopteran survival, but also conferred a direct reproductive benefit to G. xiphias females, which may abandon the first brood to ants and lay an additional clutch next to the original brood. Two years of experimental manipulations, however, showed that the degree of protection conferred by tending ants varies yearly, and that at initially high abundance of natural enemies the ant species differ in their effects on Treehopper survival. Ant effects on Treehopper fecundity also varied with time, and with shifts in the abundance of natural enemies. This is the first study to simultaneously demonstrate conditionality in ant-derived benefits related to both protection and fecundity in an ant-tended Membracidae, and the first to show the combined action of these effects in the same system.
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Ant‐Homoptera Interactions in a Neotropical Savanna: The Honeydew‐Producing Treehopper, Guayaquila xiphias (Membracidae), and its Associated Ant Fauna on Didymopanax vinosum (Araliaceae)1
Biotropica, 1999Co-Authors: Kleber Del-claro, Paulo S. OliveiraAbstract:We investigate the ant fauna associated with the Neotropical Treehopper, Guayaquila xiphias, on shrubs of Didymopanax vinosum in the cerrado (savanna) of SE Brazil. Treehoppers infested plants at the border of the cerrado almost exclusively and preferably fed near the apical meristem. During the reproductive phase of the host plant, however, the vast majority of the Treehoppers aggregated on the inflorescences. We found 21 ant species harvesting honeydew at G. xiphias aggregations, the most frequent being Camponotus rufipes, Ectatomma edentatum, C. crassus, and C. renggeri. Such a taxonomic diversity of ants tending G. xiphias aggregations in the cerrado is far greater than that reported for any other ant-homopteran system. Daily turnover of ant species at a given Treehopper aggregation was observed on 29 percent (64 out of 222) of the G. xiphias aggregations recorded on D. vinosum shrubs. Species replacements probably reflect distinct humidity and temperature ranges tolerated by the species, and may ultimately reduce interspecific competition at homopteran aggregations. Since predation and parasitism on G. xiphias can be severe, and tending ants protect the homopterans against predators and parasitoids, the round-the-clock activity by ants at G. xiphias aggregations is regarded as crucial for the survival of these Treehoppers in the cerrado.
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Honeydew flicking by Treehoppers provides cues to potential tending ants
Animal Behaviour, 1996Co-Authors: Kleber Del-claro, Paulo S. OliveiraAbstract:The honeydew-producing Treehopper, Guayaquila xiphias, is frequently tended by ants on shrubs of Didymopanax vinosum in the Brazilian savannah. Field experiments showed that the flicking of accumulated honeydew by untended Treehoppers provides cues to ground-dwelling ants. Upon finding scattered honeydew droplets on the ground, the ants climb onto the host plant and start tending activity. Honeydew-soaked filter papers placed beneath unoccupied host plants induced significantly more ants to climb onto the plant than water-soaked papers. Because predation and parasitism on G. xiphiascan be severe at early stages, and tending ants protect the homopterans against predators and parasitoids, the capacity to attract ants early in life can be crucial for Treehopper survival. ? 1996 The Association for the Study of Animal Behaviour Phloem-feeding Homoptera (primarily aphids, membracids and scales) are commonly tended by ants that harvest their energy-rich honeydew (Auclair 1963; Way 1963). Homopteran honey- dew is generally regarded as an ant attractant (Sudd 1987), and tending ants can provide a range of benefits to homopterans, including protection from natural enemies (Buckley 1987a, b, and ci- tations therein). Ant colonies may simultaneously tend many homopteran aggregations, and intra- and interspecific competition for the services of ants can adversely aVect homopteran fitness through reduced tending levels (Cushman & Addicott 1989; Cushman & Whitham 1991). Pre- dation pressure on homopteran aggregations can be severe at early developmental stages, and ant tending can greatly increase the number of surviv- ing nymphs (Bristow 1983; Cushman & Whitham 1989). Therefore, the capacity to attract ants early in life can be crucial for the survival of ant-tended homopterans, especially under low ant densities (Cushman & Addicott 1989).
Manuel A. Morales - One of the best experts on this subject based on the ideXlab platform.
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Mechanisms of aggregation in an ant-tended Treehopper: Attraction to mutualists is balanced by conspecific competition.
PloS one, 2017Co-Authors: Manuel A. Morales, Andrew G. ZinkAbstract:Understanding the spatial structure of populations and communities has been a dominant focus of ecological research, and spatial structure is increasingly seen as critical for understanding population dynamics. Habitat (or host) preference is a proximate mechanism that can generate aggregation or overdispersion, lending insight into the ultimate consequences of observed spatial distributions. Publilia concava is a univoltine phloem-feeding insect that forms mutualistic associations with ants, which consume honeydew and protect Treehoppers from predation. Treehopper adults and nymphs are aggregated at the scale of goldenrod plant stems, and previous studies have suggested that this aggregation is an adaptive response that increases feeding performance or maximizes benefits of ant-tending. Previous studies have also shown experimentally that individual Treehoppers preferentially oviposit on plants with ants present, but a complimentary hypothesis that Treehoppers prefer to oviposit near conspecifics (e.g., to take advantage of density-dependent ant attraction) remains untested. We show that, as expected, the probability of Treehopper oviposition increases with ant-presence and relative ant abundance. However, we also find that Treehopper oviposition decreases with increasing Treehopper density. Thus our results are inconsistent with the hypothesis that Treehopper aggregation is a socially cooperative strategy to attract ants; we suggest that aggregation is a form of conflict and an unavoidable by-product of individual responses to ant-tending levels.
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Parameter estimates and significance estimates at the two NY sites for the probability of oviposition by female Treehoppers as a function of per-capita ant-tending level and Treehopper density on a plant.
2017Co-Authors: Manuel A. Morales, Andrew G. ZinkAbstract:Parameter estimates and significance estimates at the two NY sites for the probability of oviposition by female Treehoppers as a function of per-capita ant-tending level and Treehopper density on a plant.
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Appendix C. ANOVA table of the natural log of ant-tending as a function of the natural log of Treehopper density, year, and season; and a table showing model parameters for Eq. 9 estimated from survivorship data.
2016Co-Authors: Manuel A. MoralesAbstract:ANOVA table of the natural log of ant-tending as a function of the natural log of Treehopper density, year, and season; and a table showing model parameters for Eq. 9 estimated from survivorship data
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Model selection analysis of temporal variation in benefit for an ant-tended Treehopper
Ecology, 2011Co-Authors: Manuel A. MoralesAbstract:Recent studies of mutualism have emphasized both that the net benefit to participants depends on the ecological context and that the density-dependent pattern of benefit is key to understanding the population dynamics of mutualism. Indeed, changes in the ecological context are likely to drive changes in both the magnitude of benefit and the density-dependent pattern of benefit. Despite the close linkage between these two areas of research, however, few studies have addressed the factors underlying variation in the density-dependent pattern of benefit. Here I use model selection to evaluate how variation in the benefits of a mutualism drives temporal variation in the density-dependent pattern of net benefit for the ant-tended Treehopper Publilia concava. In the interaction between ants and Treehoppers in the genus Publilia, ants collect the sugary excretions of Treehoppers as a food resource, and Treehoppers benefit both directly (e.g., by feeding facilitation) and indirectly (e.g., by predator protection). Results presented here show that temporal changes in the relative magnitude of direct and indirect benefit components of ant tending, especially the effectiveness of predator protection by ants, qualitatively change the overall pattern of density-dependent benefit between years with maximum benefit shifting from Treehoppers in small to large aggregations. These results emphasize the need for empirical studies that evaluate the long-term dynamics of mutualism and theoretical studies that consider the population dynamics consequences of variation in the density-dependent pattern of benefit.
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Acoustic alarm signalling facilitates predator protection of Treehoppers by mutualist ant bodyguards.
Proceedings of The Royal Society B: Biological Sciences, 2008Co-Authors: Manuel A. Morales, Jennifer L Barone, Charles S. HenryAbstract:Mutualism is a net positive interaction that includes varying degrees of both costs and benefits. Because tension between the costs and benefits of mutualism can lead to evolutionary instability, identifying mechanisms that regulate investment between partners is critical to understanding the evolution and maintenance of mutualism. Recently, studies have highlighted the importance of interspecific signalling as one mechanism for regulating investment between mutualist partners. Here, we provide evidence for interspecific alarm signalling in an insect protection mutualism and we demonstrate a functional link between this acoustic signalling and efficacy of protection. The Treehopper Publilia concava Say (Hemiptera: Membracidae) is an insect that provides ants with a carbohydrate-rich excretion called honeydew in return for protection from predators. Adults of this species produce distinct vibrational signals in the context of predator encounters. In laboratory trials, putative alarm signal production significantly increased following initial contact with ladybeetle predators (primarily Harmonia axyridis Pallas, Coleoptera: Coccinellidae), but not following initial contact with ants. In field trials, playback of a recorded Treehopper alarm signal resulted in a significant increase in both ant activity and the probability of ladybeetle discovery by ants relative to both silence and Treehopper courtship signal controls. Our results show that P. concava Treehoppers produce alarm signals in response to predator threat and that this signalling can increase effectiveness of predator protection by ants.
Arvind Varsani - One of the best experts on this subject based on the ideXlab platform.
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ICTV Virus Taxonomy Profile: Geminiviridae
Journal of General Virology, 2017Co-Authors: F. Murilo Zerbini, Rob W Briddon, Ali M. Idris, Darren P. Martin, Philippe Roumagnac, Rafael F. Rivera-bustamante, Enrique Moriones, Jesús Navas-castillo, Arvind VarsaniAbstract:The geminiviruses are a family of small, non-enveloped viruses with single-stranded, circular DNA genomes of 2500–5200 bases. Geminiviruses are transmitted by various types of insect (whiteflies, leafhoppers, Treehoppers and aphids). Members of the genus Begomovirus are transmitted by whiteflies, those in the genera Becurtovirus, Curtovirus, Grablovirus, Mastrevirus and Turncurtovirus are transmitted by specific leafhoppers, the single member of the genus Topocuvirus is transmitted by a Treehopper and one member of the genus Capulavirus is transmitted by an aphid. Geminiviruses are plant pathogens causing economically important diseases in most tropical and subtropical regions of the world. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of the Geminiviridae which is available at www.ictv.global/report/geminiviridae.
F. Murilo Zerbini - One of the best experts on this subject based on the ideXlab platform.
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ICTV Virus Taxonomy Profile: Geminiviridae
Journal of General Virology, 2017Co-Authors: F. Murilo Zerbini, Rob W Briddon, Ali M. Idris, Darren P. Martin, Philippe Roumagnac, Rafael F. Rivera-bustamante, Enrique Moriones, Jesús Navas-castillo, Arvind VarsaniAbstract:The geminiviruses are a family of small, non-enveloped viruses with single-stranded, circular DNA genomes of 2500–5200 bases. Geminiviruses are transmitted by various types of insect (whiteflies, leafhoppers, Treehoppers and aphids). Members of the genus Begomovirus are transmitted by whiteflies, those in the genera Becurtovirus, Curtovirus, Grablovirus, Mastrevirus and Turncurtovirus are transmitted by specific leafhoppers, the single member of the genus Topocuvirus is transmitted by a Treehopper and one member of the genus Capulavirus is transmitted by an aphid. Geminiviruses are plant pathogens causing economically important diseases in most tropical and subtropical regions of the world. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of the Geminiviridae which is available at www.ictv.global/report/geminiviridae.
