A systematic review of invasive non-native freshwater bivalves.

The introduction of invasive species has become an increasing environmental problem in freshwater ecosystems due to the high economic and ecological impacts it has generated. This systematic review covers publications from 2010 to 2020, focusing on non-native invasive freshwater bivalves, a particularly relevant and widespread introduced taxonomic group in fresh waters. We collected information on the most studied species, the main objectives of the studies, their geographical location, study duration, and type of research. Furthermore, we focused on assessing the levels of ecological evidence presented, the type of interactions of non-native bivalves with other organisms and the classification of their impacts. A total of 397 publications were retrieved. The studies addressed a total of 17 species of non-native freshwater bivalves; however, most publications focused on the species Corbicula fluminea and Dreissena polymorpha, which are recognised for their widespread distribution and extensive negative impacts. Many other non-native invasive bivalve species have been poorly studied. A high geographical bias was also present, with a considerable lack of studies in developing countries. The most frequent studies had shorter temporal periods, smaller spatial extents, and more observational data, were field-based, and usually evaluated possible ecological impacts at the individual and population levels. There were 94 publications documenting discernible impacts according to the Environmental Impact Classification for Alien Taxa (EICAT). However, 41 of these publications did not provide sufficient data to determine an impact. The most common effects of invasive bivalves on ecosystems were structural alterations, and chemical and physical changes, which are anticipated due to their role as ecosystem engineers. Despite a considerable number of studies in the field and advances in our understanding of some species over the past decade, long-term data and large-scale studies are still needed to understand better the impacts, particularly at the community and ecosystem levels and in less-studied geographic regions. The widespread distribution of several non-native freshwater bivalves, their ongoing introductions, and high ecological and economic impacts demand continued research. Systematic reviews such as this are essential for identifying knowledge gaps and guiding future research to enable a more complete understanding of the ecological implications of invasive bivalves, and the development of effective management strategies.

Indirect and direct drivers of floristic condition in a threatened temperate woodland.

Almost half of Earth's surface is threatened by agriculture, which has extensively degraded ecosystems and resulted in significant biodiversity loss. Remnant ecosystems in fragmented agricultural landscapes are threatened by past and present grazing and land-clearing. Declines in native diversity are common in these ecosystems, and their restoration is a key conservation goal globally. Understanding the drivers of change in floristic condition, reflecting continuity in floristic composition towards native plant communities, is fundamental to inform effective restoration practice. Previous investigations have demonstrated abiotic and biotic drivers of floristic condition independently. However, few consider the combined influence of these drivers on floristic condition, or the interactions between them, which may mediate indirect effects (e.g. plant-soil interactions). Despite this, ecological interactions may underpin changes in floristic condition, and provide critical insights needed to inform restoration. Here, we use structural equation modelling to disentangle the relationships between plants, soils and grass and litter biomass (leaf litter and fine woody debris) to elucidate the direct and indirect drivers of floristic condition in some of the most degraded landscapes globally: the critically endangered box-gum grassy woodlands in south-eastern Australia. We identify divergent plant-soil interactions between native versus exotic plants to key soil properties including soil nitrate and phosphorus. Specifically, native plants were negatively associated with increasing soil fertility, which favored exotic species. We also found evidence of indirect effects on floristic condition, mediated through interactions between litter biomass, soils and the basal area of overstorey trees. Our findings highlight the major role of soils in shaping floristic condition through direct and indirect pathways, and the role of multivariate interactions in mediating these pathways in a highly degraded, critically endangered ecosystem. Effective restoration must therefore consider the multivariate direct and indirect drivers of ecological condition to maximise positive outcomes in these landscapes and those similar.

On formal limitations of causal ecological networks.

Causal multivariate time-series analysis, combined with network theory, provide a powerful tool for studying complex ecological interactions. However, these methods have limitations often underestimated when used in graphical modelling of ecological systems. In this opinion article, I examine the relationship between formal logic methods used to describe causal networks and their inherent statistical and epistemological limitations. I argue that while these methods offer valuable insights, they are restricted by axiomatic assumptions, statistical constraints and the incompleteness of our knowledge. To prove that, I first consider causal networks as formal systems, define causality and formalize their axioms in terms of modal logic and use ecological counterexamples to question the axioms. I also highlight the statistical limitations when using multivariate time-series analysis and Granger causality to develop ecological networks, including the potential for spurious correlations among other data characteristics. Finally, I draw upon Gödel's incompleteness theorems to highlight the inherent limits of fully understanding complex networks as formal systems and conclude that causal ecological networks are subject to initial rules and data characteristics and, as any formal system, will never fully capture the intricate complexities of the systems they represent. This article is part of the theme issue 'Connected interactions: enriching food web research by spatial and social interactions'.

Interspecific interaction network of mites associated with mango trees.

Direct and indirect ecological interactions, environmental factors, and the phenology of host plants can shape the way mites interact. These relationships interfere with species occurrence and consequently alter the structure and stability of the intraplant community. As predatory mites act as regulators of herbivorous mites, we hypothesized that these mites may occupy a central position in a network of interactions among mite species associated with mango trees, and the occurrence of these species is mediated by environmental variables and the phenological stage of the host plant. We evaluated the global structure of the interaction network of mites associated with individual Mangifera indica plants and analyzed the interspecific relationships of the species using an undirected Bayesian network approach. Additionally, we observed a correlation between mite population density and plant phenological stage. Environmental variables, such as average monthly temperature, monthly precipitation, and average monthly relative humidity at different sampling date were used in the correlation analysis. The modularity at the mite-plant network level showed a low specialization index H2 = 0.073 (generalist) and high robustness (R = 0.93). Network analysis revealed that Amblyseius largoensis, Bdella ueckermanni, Parapronematus acaciae, and Tuckerella ornata occupied central positions in the assembly of mites occurring on mango trees. Environmental variables, average monthly temperature, and monthly precipitation were correlated with the occurrence of Brachytydeus formosa, Cisaberoptus kenyae, Oligonychus punicae, T. ornata, and Vilaia pamithus. We also observed a correlation between the plant phenological stage and population densities of Neoseiulus houstoni, O. punicae, P. acaciae, and V. pamithus.

Hyperparasitism in bat flies (Diptera: Streblidae): new records and interaction networks in the Neotropics.

Hyperparasitism is defined as the interaction where one parasite is infected by another parasite. In bat flies (Streblidae and Nycteribiidae), both hyperparasites and microparasites (bacteria, viruses, fungi, and arthropods such as mites) have been documented. Fungi belonging to the order Laboulbeniales are microscopic parasites of a wide diversity of arthropod hosts. Three genera exclusively target bat flies: Arthrorhynchus, which parasitizes species within Nycteribiidae in the Eastern Hemisphere, while genus Gloeandromyces and Nycteromyces parasitize Streblidae in the Western Hemisphere. Among the hyperparasitic arthropods, mites of family Neothrombidiidae, particularly the monospecific genus Monunguis, are known to parasitize bat flies. Here we present the first records of the hyperparasites Monunguis streblida and Gloeandromyces pageanus f. polymorphus parasitizing Streblidae bat flies in Colombia and a summary of these hyperparasitic interactions in the Neotropics. We detected fungi and mites parasitizing bat flies that were collected in the Magdalena River Basin, Colombia, in field expeditions in 2018, 2022, and 2023. We identified 17 bat flies and two species of hyperparasites, specifically M. streblida and the fungi Gloeandromyces. Our search for reports of these interactions in the Neotropics revealed that seven species of Trichobius (Streblidae) are parasitized by M. streblida, whereas Paratrichobius longicrus (Streblidae) is parasitized by Gloeandromyces pageanus f. polymorphus. These interactions have been reported in 11 countries, but our records are the first of M. streblida and Laboulbeniales fungi parasitizing bat flies in Colombia. So far, a total of 14 species of fungi and one species of mite have been associated with 19 species of bat flies, which in turn, are linked to 15 species of Neotropical bats.

Extracting secondary data from citizen science images reveals host flower preferences of the Mexican grass-carrying wasp Isodontia mexicana in its native and introduced ranges.

We investigated the plant-pollinator interactions of the Mexican grass-carrying wasp Isodontia mexicana-native to North America and introduced in Europe in the 1960s-through the use of secondary data from citizen science observations. We applied a novel data exchange workflow from two global citizen science platforms, iNaturalist and Pl@ntNet. Images from iNaturalist of the wasp were used to query the Pl@ntNet application to identify possible plant species present in the pictures. Simultaneously, botanists manually identified the plants at family, genus and species levels and additionally documented flower color and biotic interactions. The goals were to calibrate Pl@ntNet's accuracy in relation to this workflow, update the list of plant species that I. mexicana visits as well as its flower color preferences in its native and introduced ranges. In addition, we investigated the types and corresponding frequencies of other biotic interactions incidentally captured on the citizen scientists' images. Although the list of known host plants could be expanded, identifying the flora from images that predominantly show an insect proved difficult for both experts and the Pl@ntNet app. The workflow performs with a 75% probability of correct identification of the plant at the species level from a score of 0.8, and with over 90% chance of correct family and genus identification from a score of 0.5. Although the number of images above these scores may be limited due to the flower parts present on the pictures, our approach can help to get an overview into species interactions and generate more specific research questions. It could be used as a triaging method to select images for further investigation. Additionally, the manual analysis of the images has shown that the information they contain offers great potential for learning more about the ecology of an introduced species in its new range.

Determining the plant-pollinator network in a culturally significant food and medicine garden in the Great Lakes region.

Understanding the interactions between plants and pollinators within a system can provide information about pollination requirements and the degree to which species contribute to floral reproductive success. Past research has focused largely on interactions within monocultured agricultural systems and only somewhat on wild pollination networks. This study focuses on the culturally significant Three Sisters Garden, which has been grown and tended by many Indigenous peoples for generations in the Great Lakes Region. Here, the plant-pollinator network of the traditional Three Sisters Garden with the inclusion of some additional culturally significant plants was mapped. Important visitors in this system included the common eastern bumble bee, Bombus impatiens Cresson (Hymenoptera: Apidae), and the hoary squash bee, Xenoglossa pruinosa (Say) (Hymenoptera: Apidae), as determined by their abundances and pollinator service index (PSI) values. Understanding the key pollinators in the Three Sisters Garden links biological diversity to cultural diversity through the pollination of culturally significant plants. Further, this information could be of use in supporting Indigenous food sovereignty by providing knowledge about which wild pollinators could be supported to increase fruit and seed set within the Three Sisters Garden. Our findings can also lead to more effective conservation of important wild pollinator species.

The MTIST platform: a microbiome time series inference standardized test.

The human gut microbiome is a promising therapeutic target, but interventions are hampered by our limited understanding of microbial ecosystems. Here, we present a platform to develop, evaluate, and score approaches to learn ecological interactions from microbiome time series data. The microbiome time series inference standardized test (MTIST) comprises: a simulation framework for the in silico generation of microbiome study data akin to what is obtained with quantitative next-generation sequencing approaches, a compilation of a large curated data set generated by the simulation framework representing 648 simulated microbiome studies containing 18,360 time series, with a total of 2,182,800 species abundance measurements, and a scoring method to rank ecological inference algorithms. We use the MTIST platform to rank five implementations of microbiome inference approaches, revealing that while all algorithms performed well on ecosystems with few species (3 and 10), all algorithms failed to infer most interaction in a large ecosystem with 100 member species. However, we do find that the strongest interactions within a large ecosystem are inferred with higher success by all algorithms. Finally, we use the MTIST platform to compare different microbiome study designs, characterizing tradeoffs between samples per subject and number of subjects. Interestingly, we find that when only few samples can be collected per subject, ecological inference is most successful when these samples are collected with highest feasible temporal frequency. Taken together, we provide a computational tool to aid the development of better microbiome ecosystem inference approaches, which will be crucial towards the development of reliable and predictable therapeutic approaches that target the microbiome ecosystem.

Potential effects of brown howler monkey extinction on dispersal services in fragmented forests void of large dispersers.

The dispersal of large-seeded species strongly depends on medium-sized and large frugivores, such as primates, which are highly susceptible to population declines. In the Atlantic Forest, brown howler monkeys Alouatta guariba are medium-sized folivorous-frugivorous species that are likely to occur in small to large fragments where the largest frugivores are extinct. However, populations of this primate have been suffering from forest fragmentation, habitat loss, hunting, and the direct and indirect effects of yellow fever outbreaks, which increase the importance of understanding their role as seed dispersers and the impacts of their potential loss. The richness and abundance of large-seeded species might also be reduced in smaller fragments, which could directly affect the magnitude of the potential impact of disperser extinction on plant recruitment. Here, we tested the following mutually exclusive predictions on the effect of fragment size on plant richness and relative density of medium- and large-seeded species consumed by brown howler monkeys in fragments smaller than 1500 ha: the number and the relative density of plant species potentially affected by the local extinction of these monkeys will be (1) directly related to forest fragment size, or (2) not related to forest fragment size. Plant richness and the relative density of large- and medium-sized seed species consumed by brown howler monkeys did not vary with fragment size, corroborating our second prediction. Thus, the local extinction of brown howler monkeys would have a similar potentially negative impact on plant regeneration for the range of tested fragment sizes. We discuss the limitations of our results and suggest other lines of enquiry for the refinement of our conclusions.

Different currencies for calculating resource phenology result in opposite inferences about trophic mismatches.

Shifts in phenology are among the key responses of organisms to climate change. When rates of phenological change differ between interacting species they may result in phenological asynchrony. Studies have found conflicting patterns concerning the direction and magnitude of changes in synchrony, which have been attributed to biological factors. A hitherto overlooked additional explanation are differences in the currency used to quantify resource phenology, such as abundance and biomass. Studying an insectivorous bird (the sanderling) and its prey, we show that the median date of cumulative arthropod biomass occurred, on average, 6.9 days after the median date of cumulative arthropod abundance. In some years this difference could be as large as 21 days. For 23 years, hatch dates of sanderlings became less synchronized with the median date of arthropod abundance, but more synchronized with the median date of arthropod biomass. The currency-specific trends can be explained by our finding that mean biomass per arthropod specimen increased with date. Using a conceptual simulation, we show that estimated rates of phenological change for abundance and biomass can differ depending on temporal shifts in the size distribution of resources. We conclude that studies of trophic mismatch based on different currencies for resource phenology can be incompatible with each other.

Local people enhance our understanding of Afrotropical frugivory networks.

Afrotropical forests are undergoing massive change caused by defaunation, i.e., the human-induced decline of animal species,1 most of which are frugivorous species.1,2,3 Frugivores' depletion and their functional disappearance are expected to cascade on tree dispersal and forest structure via interaction networks,4,5,6,7 as the majority of tree species depend on frugivores for their dispersal.8 However, frugivory networks remain largely unknown, especially in Afrotropical areas,9,10,11 which considerably limits our ability to predict changes in forest dynamics and structures using network analysis.12,13,14,15 While the academic workforce may be inadequate to fill this knowledge gap before it is too late, local ecological knowledge appears as a valuable source of ecological information and could significantly contribute to our understanding of such crucial interactions for tropical forests.16,17,18,19,20,21 To investigate potential synergies between local ecological knowledge and academic knowledge,20,21 we compiled frugivory interactions linking 286 trees to 100 frugivore species from the academic literature and local ecological knowledge coming from interviews of Gabonese forest-dependent people. Here, we showed that local ecological knowledge on frugivory interactions was substantial and original, with 39% of these interactions unknown by science. We demonstrated that combining academic and local ecological knowledge affects the functional relationship linking frugivore body mass to seed size, as well as the network structure. Our results highlight the benefits of bridging knowledge systems between academics and local communities for a better understanding of the functioning and response to perturbations of Afrotropical forests.

A matter of choice: Understanding the interactions between epiphytic foraminifera and their seagrass host Halophila stipulacea.

In sub/tropical waters, benthic foraminifera are among the most abundant epiphytic organisms inhabiting seagrass meadows. This study explored the nature of the association between foraminifera and the tropical seagrass species H. stipulacea, aiming to determine whether these interactions are facilitative or random. For this, we performed a "choice" experiment, where foraminifera could colonize H. stipulacea plants or plastic "seagrasses" plants. At the end of the experiment, a microbiome analysis was performed to identify possible variances in the microbial community and diversity of the substrates. Results show that foraminifera prefer to colonize H. stipulacea, which had a higher abundance and diversity of foraminifera than plastic seagrass plants, which increased over time and with shoot age. Moreover, H. stipulacea leaves have higher epiphytic microbial community abundance and diversity. These results demonstrate that seagrass meadows are important hosts of the foraminifera community and suggest the potential facilitative effect of H. stipulacea on epiphytic foraminifera, which might be attributed to a greater diversity of the microbial community inhabiting H. stipulacea.

Predator-driven behavioural shifts in a common lizard shape resource-flow from marine to terrestrial ecosystems.

Foraging decisions shape the structure of food webs. Therefore, a behavioural shift in a single species can potentially modify resource-flow dynamics of entire ecosystems. To examine this, we conducted a field experiment to assess foraging niche dynamics of semi-arboreal brown anole lizards in the presence/absence of predatory ground-dwelling curly-tailed lizards in a replicated set of island ecosystems. One year after experimental translocation, brown anoles exposed to these predators had drastically increased perch height and reduced consumption of marine-derived food resources. This foraging niche shift altered marine-to-terrestrial resource-flow dynamics and persisted in the diets of the first-generation offspring. Furthermore, female lizards that displayed more risk-taking behaviours consumed more marine prey on islands with predators present. Our results show how predator-driven rapid behavioural shifts can alter food-web connectivity between oceanic and terrestrial ecosystems and underscore the importance of studying behaviour-mediated niche shifts to understand ecosystem functioning in rapidly changing environments.

Harvesting pollen with vibrations: towards an integrative understanding of the proximate and ultimate reasons for buzz pollination.

Buzz pollination, a type of interaction in which bees use vibrations to extract pollen from certain kinds of flowers, captures a close relationship between thousands of bee and plant species. In the last 120 years, studies of buzz pollination have contributed to our understanding of the natural history of buzz pollination, and basic properties of the vibrations produced by bees and applied to flowers in model systems. Yet, much remains to be done to establish its adaptive significance and the ecological and evolutionary dynamics of buzz pollination across diverse plant and bee systems. Here, we review for bees and plants the proximate (mechanism and ontogeny) and ultimate (adaptive significance and evolution) explanations for buzz pollination, focusing especially on integrating across these levels to synthesize and identify prominent gaps in our knowledge. Throughout, we highlight new technical and modelling approaches and the importance of considering morphology, biomechanics and behaviour in shaping our understanding of the adaptive significance of buzz pollination. We end by discussing the ecological context of buzz pollination and how a multilevel perspective can contribute to explain the proximate and evolutionary reasons for this ancient bee-plant interaction.

Evolutionary plant-pollinator responses to anthropogenic land-use change: impacts on ecosystem services.

Agricultural intensification at field and landscape scales, including increased use of agrochemicals and loss of semi-natural habitats, is a major driver of insect declines and other community changes. Efforts to understand and mitigate these effects have traditionally focused on ecological responses. At the same time, adaptations to pesticide use and habitat fragmentation in both insects and flowering plants show the potential for rapid evolution. Yet we lack an understanding of how such evolutionary responses may propagate within and between trophic levels with ensuing consequences for conservation of species and ecological functions in agroecosystems. Here, we review the literature on the consequences of agricultural intensification on plant and animal evolutionary responses and interactions. We present a novel conceptualization of evolutionary change induced by agricultural intensification at field and landscape scales and emphasize direct and indirect effects of rapid evolution on ecosystem services. We exemplify by focusing on economically and ecologically important interactions between plants and pollinators. We showcase available eco-evolutionary theory and plant-pollinator modelling that can improve predictions of how agricultural intensification affects interaction networks, and highlight available genetic and trait-focused methodological approaches. Specifically, we focus on how spatial genetic structure affects the probability of propagated responses, and how the structure of interaction networks modulates effects of evolutionary change in individual species. Thereby, we highlight how combined trait-based eco-evolutionary modelling, functionally explicit quantitative genetics, and genomic analyses may shed light on conditions where evolutionary responses impact important ecosystem services.

Insects and spiders on Acacia mangium (Fabaceae) saplings as bioindicators for the recovery of tropical degraded areas

Abstract Acacia mangium is a pioneer species with fast growth and frequently used in the recovery of degraded areas. The objectives were to evaluate insects and spiders, their ecological indices and interactions on A. mangium saplings in a tropical degraded area in recovering process. The experimental design was completely randomized with 24 replications, with treatments represented by the first and second years after A. mangium seedling planted. Numbers of leaves/branch, branches/sapling, and ground cover by A. mangium saplings, Hemiptera: Phenacoccus sp. and Pachycoris torridus; Hymenoptera: Tetragonisca angustula and Trigona spinipes, Brachymyrmex sp., Camponotus sp. and Cephalotes sp.; Blattodea: Nasutitermes sp. and Neuroptera: Chrysoperla sp.; abundance, species richness of pollinating insects, tending ants, and the abundance of Sternorrhyncha predators were greatest in the second year after planting. Numbers of Hemiptera: Aethalium reticulatum, Hymenoptera: Camponotus sp., Cephalotes sp., Polybia sp., T. angustula, T. spinipes, tending ants, pollinating insects, Sternorrhyncha predators and species richness of tending ants were highest on A. mangium saplings with greatest numbers of leaves or branches. The increase in the population of arthropods with ground cover by A. mangium saplings age increase indicates the positive impact by this plant on the recovery process of degraded areas.

Resumo Acacia mangium é uma espécie pioneira, de rápido crescimento e utilizada na recuperação de áreas degradadas. Os objetivos foram avaliar insetos e aranhas, seus índices ecológicos e interações com plantas de A. mangium em área tropical degradada em processo de recuperação. O delineamento experimental foi inteiramente casualizado com 24 repetições, com os tratamentos representados pelos primeiro e segundo anos após a plantio de A. mangium. Os números de folhas/galhos, galhos/plantas e cobertura do solo por plantas de A. mangium, de Hemiptera: Phenacoccus sp. e Pachycoris torridus; Hymenoptera: Tetragonisca angustula e Trigona spinipes, Brachymyrmex sp., Camponotus sp. e Cephalotes sp.; Blattodea: Nasutitermes sp. e Neuroptera: Chrysoperla sp.; a abundância, riqueza de espécies de insetos polinizadores, formigas cuidadoras e a abundância de predadores de Sternorrhyncha foram maiores no segundo ano após o plantio. Os números de Hemiptera: Aethalium reticulatum, Hymenoptera: Camponotus sp., Cephalotes sp., Polybia sp., T. angustula, T. spinipes, formigas cuidadoras, insetos polinizadores, predadores de Sternorrhyncha e a riqueza de espécies de formigas cuidadoras foram maiores em plantas de A. mangium com maior altura e número de folhas ou galhos. O aumento populacional de artrópodes e da cobertura do solo com o processo de envelhecimento das plantas de A. mangium indicam impacto positivo dessa planta na recuperação de áreas degradadas.

Monocrotaline presence in the Crotalaria (Fabaceae) plant genus and its influence on arthropods in agroecosystems

Abstract Crotalaria (Fabaceae) occurs abundantly in tropical and subtropical regions and has about 600 known species. These plants are widely used in agriculture, mainly as cover plants and green manures, in addition to their use in the management of phytonematodes. A striking feature of these species is the production of pyrrolizidine alkaloids (PAs), secondary allelochemicals involved in plant defense against herbivores. In Crotalaria species, monocrotaline is the predominant PA, which has many biological activities reported, including cytotoxicity, tumorigenicity, hepatotoxicity and neurotoxicity, with a wide range of ecological interactions. Thus, studies have sought to elucidate the effects of this compound to promote an increase in flora and fauna (mainly insects and nematodes) associated with agroecosystems, favoring the natural biological control. This review summarizes information about the monocrotaline, showing such effects in these environments, both above and below ground, and their potential use in pest management programs.

Resumo Crotalaria (Linnaeus, 1753) (Fabaceae) ocorre abundantemente em regiões tropicais e subtropicais e tem cerca de 600 espécies conhecidas. Estas plantas são amplamente utilizadas na agricultura, principalmente como cobertura e adubos verdes, além da sua utilização no manejo de fitonematoides. Uma característica marcante destas espécies é a produção de alcalóides pirrolizidinicos (APs), aleloquímicos secundários envolvidos na defesa das plantas contra os herbívoros. Nas espécies de Crotalaria, a monocrotalina é a AP predominante, que tem muitas atividades biológicas relatadas, incluindo citotoxicidade, tumorigenicidade, hepatotoxicidade e neurotoxicidade, além de uma vasta gama de interações ecológicas. Assim, estudos têm procurado elucidar os efeitos desse composto para promover um incremento na flora e fauna (principalmente insetos e nematoides) associados aos agroecossistemas, favorecendo o controle biológico natural. Esta revisão compila informações sobre a monocrotalina, mostrando tais efeitos nesses ambientes, tanto acima como abaixo do solo e a sua potencial utilização em programas de manejo de pragas.

Insects and spiders on Acacia mangium (Fabaceae) saplings as bioindicators for the recovery of tropical degraded areas / Insetos e aranhas em plantas de Acacia mangium (Fabaceae) como bioindicadores na recuperação de área tropical degradada

Abstract Acacia mangium is a pioneer species with fast growth and frequently used in the recovery of degraded areas. The objectives were to evaluate insects and spiders, their ecological indices and interactions on A. mangium saplings in a tropical degraded area in recovering process. The experimental design was completely randomized with 24 replications, with treatments represented by the first and second years after A. mangium seedling planted. Numbers of leaves/branch, branches/sapling, and ground cover by A. mangium saplings, Hemiptera: Phenacoccus sp. and Pachycoris torridus; Hymenoptera: Tetragonisca angustula and Trigona spinipes, Brachymyrmex sp., Camponotus sp. and Cephalotes sp.; Blattodea: Nasutitermes sp. and Neuroptera: Chrysoperla sp.; abundance, species richness of pollinating insects, tending ants, and the abundance of Sternorrhyncha predators were greatest in the second year after planting. Numbers of Hemiptera: Aethalium reticulatum, Hymenoptera: Camponotus sp., Cephalotes sp., Polybia sp., T. angustula, T. spinipes, tending ants, pollinating insects, Sternorrhyncha predators and species richness of tending ants were highest on A. mangium saplings with greatest numbers of leaves or branches. The increase in the population of arthropods with ground cover by A. mangium saplings age increase indicates the positive impact by this plant on the recovery process of degraded areas.

Resumo Acacia mangium é uma espécie pioneira, de rápido crescimento e utilizada na recuperação de áreas degradadas. Os objetivos foram avaliar insetos e aranhas, seus índices ecológicos e interações com plantas de A. mangium em área tropical degradada em processo de recuperação. O delineamento experimental foi inteiramente casualizado com 24 repetições, com os tratamentos representados pelos primeiro e segundo anos após a plantio de A. mangium. Os números de folhas/galhos, galhos/plantas e cobertura do solo por plantas de A. mangium, de Hemiptera: Phenacoccus sp. e Pachycoris torridus; Hymenoptera: Tetragonisca angustula e Trigona spinipes, Brachymyrmex sp., Camponotus sp. e Cephalotes sp.; Blattodea: Nasutitermes sp. e Neuroptera: Chrysoperla sp.; a abundância, riqueza de espécies de insetos polinizadores, formigas cuidadoras e a abundância de predadores de Sternorrhyncha foram maiores no segundo ano após o plantio. Os números de Hemiptera: Aethalium reticulatum, Hymenoptera: Camponotus sp., Cephalotes sp., Polybia sp., T. angustula, T. spinipes, formigas cuidadoras, insetos polinizadores, predadores de Sternorrhyncha e a riqueza de espécies de formigas cuidadoras foram maiores em plantas de A. mangium com maior altura e número de folhas ou galhos. O aumento populacional de artrópodes e da cobertura do solo com o processo de envelhecimento das plantas de A. mangium indicam impacto positivo dessa planta na recuperação de áreas degradadas.

Monocrotaline presence in the Crotalaria (Fabaceae) plant genus and its influence on arthropods in agroecosystems / Presença de monocrotalina em plantas do gênero Crotalaria (Fabaceae) e a sua influência sobre artrópodes nos agroecossistemas

Abstract Crotalaria (Fabaceae) occurs abundantly in tropical and subtropical regions and has about 600 known species. These plants are widely used in agriculture, mainly as cover plants and green manures, in addition to their use in the management of phytonematodes. A striking feature of these species is the production of pyrrolizidine alkaloids (PAs), secondary allelochemicals involved in plant defense against herbivores. In Crotalaria species, monocrotaline is the predominant PA, which has many biological activities reported, including cytotoxicity, tumorigenicity, hepatotoxicity and neurotoxicity, with a wide range of ecological interactions. Thus, studies have sought to elucidate the effects of this compound to promote an increase in flora and fauna (mainly insects and nematodes) associated with agroecosystems, favoring the natural biological control. This review summarizes information about the monocrotaline, showing such effects in these environments, both above and below ground, and their potential use in pest management programs.

Resumo Crotalaria (Linnaeus, 1753) (Fabaceae) ocorre abundantemente em regiões tropicais e subtropicais e tem cerca de 600 espécies conhecidas. Estas plantas são amplamente utilizadas na agricultura, principalmente como cobertura e adubos verdes, além da sua utilização no manejo de fitonematoides. Uma característica marcante destas espécies é a produção de alcalóides pirrolizidinicos (APs), aleloquímicos secundários envolvidos na defesa das plantas contra os herbívoros. Nas espécies de Crotalaria, a monocrotalina é a AP predominante, que tem muitas atividades biológicas relatadas, incluindo citotoxicidade, tumorigenicidade, hepatotoxicidade e neurotoxicidade, além de uma vasta gama de interações ecológicas. Assim, estudos têm procurado elucidar os efeitos desse composto para promover um incremento na flora e fauna (principalmente insetos e nematoides) associados aos agroecossistemas, favorecendo o controle biológico natural. Esta revisão compila informações sobre a monocrotalina, mostrando tais efeitos nesses ambientes, tanto acima como abaixo do solo e a sua potencial utilização em programas de manejo de pragas.