Caterpillars and fungal pathogens: two co-occurring parasites of an ant-plant mutualism

In mutualisms, each interacting species obtains resources from its partner that it would obtain less efficiently if alone, and so derives a net fitness benefit. In exchange for shelter (domatia) and food, mutualistic plant-ants protect their host myrmecophytes from herbivores, encroaching vines and fungal pathogens. Although selective filters enable myrmecophytes to host those ant species most favorable to their fitness, some insects can by-pass these filters, exploiting the rewards supplied whilst providing nothing in return. This is the case in French Guiana for Cecropia obtusa (Cecropiaceae) as Pseudocabima guianalis caterpillars (Lepidoptera, Pyralidae) can colonize saplings before the installation of their mutualistic Azteca ants. The caterpillars shelter in the domatia and feed on food bodies (FBs) whose production increases as a result. They delay colonization by ants by weaving a silk shield above the youngest trichilium, where the FBs are produced, blocking access to them. This probable temporal priority effect also allows female moths to lay new eggs on trees that already shelter caterpillars, and so to occupy the niche longer and exploit Cecropia resources before colonization by ants. However, once incipient ant colonies are able to develop, they prevent further colonization by the caterpillars. Although no higher herbivory rates were noted, these caterpillars are ineffective in protecting their host trees from a pathogenic fungus, Fusarium moniliforme (Deuteromycetes), that develops on the trichilium in the absence of mutualistic ants. Therefore, the Cecropia treelets can be parasitized by two often overlooked species: the caterpillars that shelter in the domatia and feed on FBs, delaying colonization by mutualistic ants, and the fungal pathogen that develops on old trichilia. The cost of greater FB production plus the presence of the pathogenic fungus likely affect tree growth

The Lancet Countdown: tracking progress on health and climate change.

Published onlineReviewJournal ArticleThis is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.The Lancet Countdown: tracking progress on health and climate change is an international, multidisciplinary research collaboration between academic institutions and practitioners across the world. It follows on from the work of the 2015 Lancet Commission, which concluded that the response to climate change could be "the greatest global health opportunity of the 21st century". The Lancet Countdown aims to track the health impacts of climate hazards; health resilience and adaptation; health co-benefits of climate change mitigation; economics and finance; and political and broader engagement. These focus areas form the five thematic working groups of the Lancet Countdown and represent different aspects of the complex association between health and climate change. These thematic groups will provide indicators for a global overview of health and climate change; national case studies highlighting countries leading the way or going against the trend; and engagement with a range of stakeholders. The Lancet Countdown ultimately aims to report annually on a series of indicators across these five working groups. This paper outlines the potential indicators and indicator domains to be tracked by the collaboration, with suggestions on the methodologies and datasets available to achieve this end. The proposed indicator domains require further refinement, and mark the beginning of an ongoing consultation process-from November, 2016 to early 2017-to develop these domains, identify key areas not currently covered, and change indicators where necessary. This collaboration will actively seek to engage with existing monitoring processes, such as the UN Sustainable Development Goals and WHO's climate and health country profiles. The indicators will also evolve over time through ongoing collaboration with experts and a range of stakeholders, and be dependent on the emergence of new evidence and knowledge. During the course of its work, the Lancet Countdown will adopt a collaborative and iterative process, which aims to complement existing initiatives, welcome engagement with new partners, and be open to developing new research projects on health and climate change.The Lancet Countdown would like to thank the Wellcome Trust for its financial and technical support—without which, this research collaboration would not be possible. While carrying out its work, the Lancet Countdown received invaluable technical advice and input from a number of individuals, including Ari Bernstein (Harvard University), Victoria Bignet (Stockholm Resilience Centre), Sarah Chaytor (University College London), Niheer Dasandi (University of Birmingham), Victor Galaz (Stockholm Resilience Centre), Janie Maxwell (University of Melbourne), Slava Mikhaylov (University College London), Neil Morisetti (University College London), Steve Pye (University College London), George Smeeton (Energy and Climate Intelligence Unit), Olivia Stevenson (University College London), Rebecca Taylor (University College London), and Koko Warner (UN Framework Convention on Climate Change). Administrative and communications support was provided by Richard Black (Energy and Climate Intelligence Unit), Pete Chalkley (Energy and Climate Intelligence Unit), Tom Fern (European Climate Foundation), Jack Fisher (Lancet Countdown), and Sarah Hurtes (European Climate Foundation). Researchers at Tsinghua University (YB, PG, YL, BX, JY, YY, and CY) wish to express their gratitude to the Cyrus Tang Foundation for financial support

Corrigendum: Translating planetary health principles into sustainable primary care services.

[This corrects the article DOI: 10.3389/fpubh.2022.931212.]

Divergent Chemical Cues Elicit Seed Collecting by Ants in an Obligate Multi-Species Mutualism in Lowland Amazonia

In lowland Amazonian rainforests, specific ants collect seeds of several plant species and cultivate them in arboreal carton nests, forming species-specific symbioses called ant-gardens (AGs). In this obligate mutualism, ants depend on the plants for nest stability and the plants depend on ant nests for substrate and nutrients. AG ants and plants are abundant, dominant members of lowland Amazonian ecosystems, but the cues ants use to recognize the seeds are poorly understood. To address the chemical basis of the ant-seed interaction, we surveyed seed chemistry in nine AG species and eight non-AG congeners. We detected seven phenolic and terpenoid volatiles common to seeds of all or most of the AG species, but a blend of the shared compounds was not attractive to the AG ant Camponotus femoratus. We also analyzed seeds of three AG species (Anthurium gracile, Codonanthe uleana, and Peperomia macrostachya) using behavior-guided fractionation. At least one chromatographic fraction of each seed extract elicited retrieval behavior in C. femoratus, but the active fractions of the three plant species differed in polarity and chemical composition, indicating that shared compounds alone did not explain seed-carrying behavior. We suggest that the various AG seed species must elicit seed-carrying with different chemical cues

Climate change and health: time for action!

Abstract Issue For several weeks, prophylactic messages against the extension of Covid-19 have saturated the public space. To protect populations, efficient measures have been rapidly put to limit the movement of people and manufactured goods. These policies have reduced global greenhouse gas emissions as well as air pollution, especially in China. Problem If climate change were an epidemic, we would probably have already restored it. But it results directly from the thermo-industrial activities linked to the consumption society. For Friel (Lancet, 2020), the dramatic consequences of this disturbances have to be considered as an essential health issue. She advocates for 'climate change and health alliances'. Results Within such alliances, health professionals have the responsibility (1) to describe the morbidity inherent in our thermo-industrial societies (2) to alert populations, and (3) to work with allies to tackle climate change and protect human populations, starting with the most vulnerable. This type of alliance is underway in the battle against air pollution, as it has been for years for fighting smoking. Alliances are intended to extend to all population health issues, with a complete decompartmentalization of minds and practices at large scale. Lessons Health professionals have to be mindful not to cause any harm while practicing. The health system alone produces up to 8% of global greenhouse gas in developed countries (Pichler, 2019; HCWH, 2019). There is room for action. Since 2009, the British health care system (NHS) has adopted an efficient decarbonation policy, reducing global emission from 8 to 4%, but this outstanding initiative remains an exception worldwide. Key messages A review of public health strategies is necessary to meet the energy, environmental and health issues, both in terms of health risks due to climate change and of decarbonation of care activities. Health professionals have the responsibility to alert populations and to work with allies to tackle climate change and protect human populations. </jats:sec