Diana Obregon

Proximity to natural habitat is known to enhance pollination services in large‐scale agriculture, but it remains unclear whether this holds in tropical smallholder farms. These systems are embedded in ecologically complex landscapes, central to global food security, and depend heavily on biodiversity‐derived ecosystem services. We conducted a systematic review and meta‐analysis of 35 studies assessing the relationship between distance to natural habitat and pollinator abundance, species richness, and crop fruit set in tropical smallholder farms. We found no consistent patterns in pollinator abundance and crop fruit set with increasing distance, with relationships highly variable across studies. Similarly variable, yet slightly negative, was the relationship between distance and pollinator species richness. Our findings suggest limited support for the ‘proximity to natural habitat’ hypothesis in tropical smallholder farms, indicating that the inherent complexity of these landscapes may buffer negative effects of distance on pollination. This underscores the importance of maintaining and restoring landscape complexity to sustain biodiversity and ecosystem services such as crop pollination. We also highlight the need for greater methodological consistency and publicly available raw data in future studies to strengthen the evidence base and support management strategies for safeguarding pollination services in tropical smallholder farms.

Deforestation rapidly increases in tropical regions, primarily driven by converting natural habitats into pastures for extensive cattle ranching. This landscape transformation, coupled with pesticide use, are key drivers of bee population decline. Here, we investigate the impact of pasture-dominated landscapes on colony performance, pesticide exposure, and insecticide sensitivity of the stingless bee Tetragonisca angustula. We monitored 16 colonies located in landscapes with varying proportions of pasture. We collected bee bread for pesticide and palynological analysis. We found a positive correlation between pollen diversity and colony growth, with no effect of the proportion of pasture in the landscape. In contrast, we detected prevalent and hazardous concentrations of the insecticide abamectin (9.6–1,856 µg/kg) in bee bread, which significantly increased with a higher proportion of pasture. Despite the abamectin exposure, the bee colonies displayed no adverse effects on their growth, indicating a potential tolerance response. Further investigations revealed that bees from sites with higher proportions of pasture showed significantly reduced mortality when exposed to a lethal concentration of abamectin (0.021 µg/µL) after 48 h. Since abamectin is scarcely used in the study area, we designed an experiment to track ivermectin, a closely related antiparasitic drug used in cattle. Our findings uncovered a new exposure route of bees to pesticides, wherein ivermectin excreted by cattle is absorbed and biotransformed into abamectin within flowering plants in the pastures. These results highlight that unexplained exposure routes of bees to pesticides remain to be described while also revealing that bees adapt to changing landscapes.

A major challenge in sustainable agriculture is finding solutions to manage crop-damaging pests such as herbivores while protecting beneficial organisms such as pollinators. Squash is a highly pollinator-dependent crop that is also attractive to herbivores like the striped cucumber beetle. While synthetic insecticides can provide control of insect pests, they can also affect non-target organisms such as pollinators. Thus, growers need to balance pest management with pollinator protection to ensure optimal yield. Thiamethoxam is a commonly used systemic insecticide that translocates throughout plants, leaving residues in nectar and pollen. The aim of this study was to evaluate whether there are uses of this insecticide that provides efficient pest control while minimizing pesticide pollinator exposure. Specifically, we tested how different prophylactic application methods (seed treatments, in-furrow applications, and early foliar sprays) of commercially available thiamethoxam products impact pest control, bee visitation, yield, and pesticide residues in flowers of squash crops. We found that among the different methods of thiamethoxam application, in-furrow application best prevented defoliation and resulted in the highest fruit weight and number. However, it also produced the most frequent and highest concentrations of thiamethoxam in nectar and pollen, reaching lethal levels for squash bees. Our study provides evidence that under current application methods, thiamethoxam does not provide a sustainable solution for squash growers and further research is required on more efficient pesticide delivery methods, as well as non-pesticide pest control measurements.

Land-use change and pesticides have been identified as two of the main causes behind pollinator decline. Understanding how these factors affect crop pollinator communities is crucial to inform practices that generate optimal pollination and ensure sustainable food production. In this study, we investigated the effects of landscape composition and pesticide residues on bee communities and their pollination services in Solanum quitoense “lulo” crops in Colombia. On 10 farms, located along a gradient of landscape complexity that varied from 0.15 to 0.62 in their natural habitat proportion, we characterized the bee community visiting the crop, and carried out pollination experiments with bagged and open inflorescences to later estimate fruit set, weight, and diameter at every site. Additionally, we performed pesticide analysis on collected anthers through liquid chromatography to estimate pesticide risk coming from the crop fields using hazard quotients (HQ). Bee abundance and species richness decreased with increased HQ, but these negative pesticide effects were less detrimental in farms with higher natural habitat proportions. However, this buffer effect was lost at sites with very high HQs. Imidacloprid was frequently found in the anthers and there were extremely high concentrations in some farms (0.6 to 13063 μg/kg), representing the molecule of greater risk for bees in this context. Pollinator’s importance to crop yield was demonstrated in the exclusion experiments, where we found a reduction in fruit set (51%), weight (39%), and diameter (25%). We found a significant effect of bee richness on fruit set, while landscape composition and HQ had no significant effect on fruit set, suggesting that the last two factors do not affect yield directly, but indirectly through a decrease in pollinator diversity. Our results provide novel evidence that the natural habitat loss due to the expansion of pastures for cattle ranching and pesticide residues in anthers reduce bee diversity and abundance in this Andean cropping system, but strategies to protect and restore natural habitat can help to buffer, until certain levels, these negative effects. Highlights: - We explored how landscape composition and pesticide residues impact bee communities and pollination services in Solanum quitoense crops. - As the proportion of natural habitat in the landscape increased, bee richness also increased. While as pesticide hazard quotients in S. quitoense anthers increased, bee diversity and abundance decreased. - The natural habitat surrounding farms mitigates the negative pesticide effects on bees when hazard quotients are low/medium, but not when they are high. - S. quitoense crops are highly dependent on bees for optimum yield.

En el año 2008, la Organización Mundial de la Salud publicó un informe llamado Subsanar las desigualdades en una generación: Alcanzar la equidad sanitaria actuando sobre los determinantes sociales de la salud. Se trata de un estudio relevante sobre la salud pública mundial que apareció quince años después que el Banco Mundial publicara, en 1993, su informe histórico, Invertir en salud que marcó el paso del liderazgo de la OMS al Banco Mundial. En este artículo, examino la relación entre esos dos informes en el contexto del tercermundismo, de las políticas del desarrollo (1950-1980) y de la globalización (1980-2008). Aunque las ideas tras el Informe de 2008 no son nuevas, tal como lo reconoce la Comisión sobre Determinantes Sociales de la Salud (CDSS), creada por la OMS y autora del documento, este informe marca un regreso crucial a la retórica sobre la Atención Primaria de Salud, como ya lo había hecho la OMS en 1978, cuando introdujo su “Salud para todos en el año 2000”. El Informe se distancia del estudio del Banco Mundial de 1993 y de las políticas neoliberales que lo siguieron. Sin embargo, la nueva retórica sobre la salud dirigida hacia el desarrollo y la reducción de la pobreza dista mucho de ser crítica con tales políticas neoliberales y es, más bien, coherente con el giro más reciente que, con respecto a las políticas globales, han tomado el Banco Mundial y el Fondo Monetario Internacional (FMI).

La badea es una fruta exótica muy apetecida, que ha encontrado barreras para ampliar su comercialización en fresco debido a la fragilidad de su cáscara y alto contenido de agua, por lo que una alternativa a este inconveniente es la venta de la fruta procesada. En este estudio se evaluó el impacto de la remoción de la semilla y el escaldado sobre las características fisicoquímicas (acidez, pH, grados Brix) y microbiológicas (unidades formadoras de colonia) de la pulpa en congelamiento durante 12 días. Como resultado se encontró que el escaldado y la remoción de las semillas ayudan a mantener las características originales de la pulpa y reducen el riesgo de contaminación con microorganismos

La mayoría de las pasifloráceas cultivadas presentan algún tipo de autoincompatiblidad en su reproducción, por tanto, requieren de polinización cruzada. Este servicio es prestado por abejas solitarias de gran tamaño, de los géneros Xylocopa, Centris y Epicharis, sin embargo, estas abejas no solo se alimentan de las flores del cultivo, sino que requieren de una variedad de recursos florales para mantener sus poblaciones y ofrecer un servicio óptimo de polinización. En este trabajo se investigaron las fuentes florales complementarias que usan los polinizadores en cultivos de badea, cholupa y maracuyá en Yopal, Casanare, con el fin de promover la conservación de estas plantas claves. Para ello, las abejas fueron capturadas para remover el polen corporal, que luego fue acetolizado e identificado en el microscopio, así se encontró que, para los tres géneros de abejas, la planta Chrysobalanus icaco es una importante fuente de alimento; también la familia Fabaceae con Gliricida sepium, Vigna spp. y Cassia spp, para Centris, también es fundamental plantas de la familia Malpighiaceae, por ser una especie recolectora de aceites florales de estas plantas

Since the 1920s, the medical community realized that the strategy of leprosy control based on segregation and persecution of patients was inefficient and expensive. In the 1930s the new liberal government incorporated leprosy within the general sanitary institutions, by merging the Bureau of Lazarettos and the National Department of Hygiene. The disease-apart approach started to be replaced by a more general public health strategy, which involved controlling other illnesses. Prevention and research played a more influential role, and the new sanitary officials saw leprosy in the light of the economic rationality of expenditures, placing more emphasis on therapies and making them mandatory for all patients. Improvements in leprosy treatment became widely known and available. However, the image of leprosy as a special condition and the practice of segregation were deeply entrenched within the Colombian culture and institutions. The rhetoric changed, but to break with several decades of persecution was a difficult task