Understanding the factors that drive community‐wide assembly of plant‐pollinator systems along environmental gradients has considerable evolutionary, ecological, and applied significance. Variation in thermal environments combined with intrinsic differences among pollinators in thermal biology have been proposed as drivers of community‐wide pollinator gradients, but this suggestion remains largely speculative. We test the hypothesis that seasonality in bee pollinator composition in Mediterranean montane habitats of southeastern Spain, which largely reflects the prevalence during the early flowering season of mining bees (Andrena), is a consequence of the latter's thermal biology. Quantitative information on seasonality of Andrena bees in the whole plant community (275 plant species) and their thermal microenvironment was combined with field and laboratory data on key aspects of the thermal biology of 30 species of Andrena (endothermic ability, warming constant, relationships of body temperature with ambient and operative temperatures). Andrena bees were a conspicuous, albeit strongly seasonal component of the pollinator assemblage of the regional plant community, visiting flowers of 153 different plant species (57% of total). The proportion of Andrena relative to all bees reached a maximum among plant species which flowered in late winter and early spring, and declined precipitously from May onward. Andrena were recorded only during the cooler segment of the annual range of air temperatures experienced at flowers by the whole bee assemblage. These patterns can be explained by features of Andrena's thermal biology: null to weak endothermy; ability to forage at much lower body temperature than strongly endothermic bees (difference ~ 10°C); low upper tolerable limit of body temperature, beyond which thermal stress presumably precluded foraging at the warmest period of year; weak thermoregulatory capacity; and high warming constant enhancing ectothermic warming. Our results demonstrate the importance of lineage‐specific pollinator traits as drivers of seasonality in community‐wide pollinator composition; show that exploitation of cooler microclimates by bees does not require strong endothermy; and suggest that intense endothermy and precise thermoregulation probably apply to a minority of bees. Medium‐ and large‐sized bees with low upper thermal limits and weak thermoregulatory ability can actually be more adversely affected by climate warming than large, hot‐blooded, extremely endothermic species.

Understanding the factors that drive community-wide assembly of plant-pollinator systems along environmental gradients has considerable evolutionary, ecological and applied significance. Variation in thermal environments combined with intrinsic differences among pollinators in thermal biology (tolerance limits, thermal optima, thermoregulatory ability) have been proposed as drivers of community-wide pollinator gradients, but this suggestion remains largely speculative. We test the hypothesis that seasonality in bee pollinator composition in montane habitats of southeastern Spain, which largely reflects the prevalence during the early flowering season of mining bees (Andrena), is a consequence of the latter's thermal biology. Quantitative information on seasonality of Andrena bees in the whole plant community (275 plant species) was combined with field and laboratory data on key aspects of the thermal biology of 30 species of Andrena (endothermic ability, warming constant, relationships of body temperature with ambient and operative temperatures). Andrena bees were a conspicuous, albeit strongly seasonal component of the pollinator assemblage of the regional plant community, visiting flowers of 153 different plant species (57% of total). Proportion of Andrena relative to all bees reached a maximum among plant species which flowered in late winter and early spring, and declined precipitously from May onwards. Andrena were recorded only during the cooler segment of the annual range of air temperatures experienced at flowers by the whole bee assemblage. These patterns can be explained by features of Andrena's thermal biology: null or negligible endothermy; ability to forage at much lower body temperature than endothermic bees (difference ~10 C); low upper tolerable limit of body temperature, beyond which thermal stress presumably precluded foraging at the warmest period of year; weak thermoregulatory capacity; and high warming constant enhancing ectothermic warming. Our results demonstrate the importance of lineage-specific pollinator traits as drivers of seasonality in community-wide pollinator composition; show that exploitation of cooler microclimates by bees does not require endothermy; falsify the frequent assumption that endothermy and thermoregulation apply to all bees; and suggest that medium- and large-sized ectothermic bees with low upper thermal limits and weak thermoregulatory ability can actually be more adversely affected by climate warming than large endothermic species.

1. Intensification of agricultural landscapes to fulfil increased global food demands has dramatically impacted biodiversity and ecosystem services.Several pollinator groups, which are vital for the maintenance of pollinatordependent crops, have been severely affected by this intensification process. Management tools, such as the implementation of agri-environmental schemes, have been widely proposed to improve pollinator's communities and pollination services, although the effectiveness of wildflower strips in comparison to existing natural or semi-natural habitats and the impact on yield has not been fully demonstrated.2. Here, we aimed to assess the effect of flower strips implementation near sunflower fields in two intensive agricultural regions and to quantify their impact on visitation rates and sunflower productivity. Data were obtained in two regions in Spain (Burgos and Cuenca) in sunflower fields with associated semi-natural vegetation (SNVs), with implemented wildflower strips (WFSs) and without vegetation structures (NonVs). Visitation rates were monitored over 2 years by direct observations, and both sunflower seed production and weight were assessed in 52 fields per year.3. Our results revealed regional and inter-annual variation in visitation rates, likely driven by structural differences in the landscapes studied. In Cuenca, characterized by more heterogeneous and floral resources-richer landscapes, the effects of WFSs were significant in the second year of implementation, with higher visitation rates and productivity values in fields with implemented wildflower strips compared to those without. In contrast, in Burgos, no consistent effects among field treatments between years were observed.

Las abejas son un grupo extremadamente diverso con más de 1000 especies descritas en la península ibérica. Además, son excelentes polinizadores y aportan numerosos servicios ecosistémicos fundamentales para la mayoría de ecosistemas terrestres. Debido a los diversos cambios ambientales inducidos por el ser humano, existen evidencias del declive de algunas de sus poblaciones para ciertas especies. Sin embargo, conocemos muy poco del estado de conservación de la mayoría de especies y de muchas de ellas ignoramos cuál es su distribución en la península ibérica. En este trabajo presentamos un esfuerzo colaborativo para crear una base de datos de ocurrencias de abejas que abarca la península ibérica e islas Baleares que permitirá resolver cuestiones como la distribución de las diferentes especies, preferencia de hábitat, fenología o tendencias históricas. En su versión actual, esta base de datos contiene un total de 87 684 registros de 923 especies recolectados entre 1830 y 2022, de los cuales un 87% presentan información georreferenciada. Para cada registro se incluye información relativa a la localidad de muestreo (89%), identificador y colector de la especie (64%), fecha de captura (54%) y planta donde se recolectó (20%). Creemos que esta base de datos es el punto de partida para conocer y conservar mejor la biodiversidad de abejas en la península ibérica e Islas Baleares. Se puede acceder a estos datos a través del siguiente enlace permanente: https://doi.org/10.5281/zenodo.6354502

La polinización del chirimoyo (Annona cherimola Miller) es uno de los aspectos más críticos de este cultivo debido a la dicogamia protogínica. Estudios muestran que el chirimoyo es polinizado por insectos silvestres, principalmente coleópteros. Sin embargo, en países donde el chirimoyo no crece naturalmente la polinización natural es deficiente. Por lo tanto, se realiza polinización manual la cual representa hasta un 50% de los costos operacionales del cultivo. El principal objetivo de este estudio fue caracterizar los visitantes florales del chirimoyo en Chile central. Los muestreos se realizaron durante la floración del chirimoyo ocurrida en enero y febrero de 2018, en tres huertos comerciales manejados con poda baja y una cubierta de herbáceas en la comuna de Quillota, Región de Valparaíso, Chile central. Se encontraron adultos del género Melanophthalma Motschulsky dentro de las flores de chirimoyo. Varios de esos individuos portaban polen de dicha especie vegetal adherido a diversas estructuras de su cuerpo, lo que posiciona a especies de este género como posibles polinizadores del cultivo de chirimoyo en Chile central.