Maureen Murúa

Pollinator diversity is declining worldwide, mainly due to agricultural habitat loss, threatening wild plant reproduction and crop pollination. Although natural habitat supports pollination services in agricultural landscapes, the amount needed remains unclear. We assessed how the percentage of natural habitat (NH) and distance from the orchard edge (DFE) influence pollinator richness and abundance in sweet cherry and apple orchards in Mediterranean central Chile. Twenty‐seven orchards of each crop were sampled over 2 years, classified by NH within a 1‐km buffer (70%). Pan traps surveyed pollinators at three distances from the orchard edge to the crop interior (0, 70 and 140 m). Both crops were modelled jointly, as crop identity did not affect pollinator richness, abundance, or honey bee abundance. Wild pollinator richness and abundance were higher with more surrounding natural habitat and decreased with distance from the edge. This decline was steeper in orchards with less natural habitat, buffering the edge effect. Honey bee abundance was unaffected by NH or DFE, and both wild pollinator and honey bee metrics were lower in the second year. Species composition differed significantly among NH categories, crops and years, although crop‐ and year‐related differences were each driven by only a small subset of taxa. Most species contributing to compositional differences among NH categories increased in abundance with NH, and none were more abundant in orchards with less than 35% NH. Our results suggest that landscapes with at least 35% of NH may better maintain wild pollinator diversity, although this value should not be interpreted as a biological threshold.

Biological invasions are a major driver of biodiversity loss. Invasive pollinators can reshape native plant-pollinator networks. This study, taking Chile as an example, is divided into two parts. First, we assessed the impacts of three non-native pollinator species ( Apis mellifera , Bombus terrestris and Bombus ruderatus ) using over 2,100 records from scientific literature (including historical data) and citizen-science databases. Interactions were classified by plant origin (native or non-native) and analysed to characterise species roles. We found that B. terrestris dominated the interactions (73%), primarily with non-native plants and all three species exhibited generalist interaction patterns. Then, we evaluated the impact of B. terrestris on bee-plant interactions by building bipartite networks representing periods before and after 2005, when B. terrestris began to be used in open fields. We analysed network metrics including nestedness, specialisation, modularity and core-periphery structure, revealing that B. terrestris increased interaction frequency, displaced native species such as Bombus dahlbomii and contributed to a more nested, but less specialised network. Overall, our findings reveal that invasive bees silently, but profoundly reshape pollination networks – displacing native pollinators, reducing interaction specialisation and shifting systems towards homogenised structures that threaten native plant-pollinator mutualisms.

Sweet cherry production relies heavily on managed and wild insect pollinators. Pollination success depends not only on the presence of flower visitors but also on their behaviour and traits. Although Chile is among the world's leading cherry producers, information on the diversity and pollination roles of insect visitors in its orchards remains scarce. In this study, we used video monitoring to assess the foraging behaviour of floral visitors in 16 conventional orchards in central Chile. In 2023, we recorded 3012 insect visits. Bees comprised 65% of visits, with honey bees ( Apis mellifera ) alone accounting for 64% and fewer than 1% for wild bees. Besides, 33% of the visits were attributed to flies—mainly Dilophus sp. (Bibionidae) and several syrphid species—and 2% to beetles. Bees spent the shortest time per flower, exhibited greater inter‐floral movement and contacted the stigma most frequently, behaviours associated with high pollination potential. In contrast, flies and beetles typically remained longer on flowers, moved little between them and often consumed floral resources without making contact with the stigma. These behavioural patterns suggest that hymenopterans are the most effective pollinators in these systems. Nevertheless, the high abundance of flies in the orchards may partly compensate for their limited pollination efficiency. Additionally, we found a significant positive relationship between body size and the likelihood of stigma contact, highlighting a key morphological trait associated with pollination effectiveness. The overall low diversity and small size of floral visitors in these conventional cherry orchards may explain why few of the species present have the potential to be effective pollinators. Promoting practices that enhance bee floral visitor diversity could increase the presence of alternative pollinators, reduce reliance on managed honeybees and contribute to more stable cherry yields.

Although Syrphidae is an essential family of flies because they provide key ecosystem services like pollination and pest control, their richness and abundance respond negatively to urbanisation, even when high‐quality green spaces are present. These are the conclusions of many studies from the northern hemisphere; however, there are shortfalls in our knowledge of flower fly ecology in Neotropical megacities. We used a 10‐year dataset obtained from a long‐term citizen science program devoted to flies to test whether the richness, total number of records (as a proxy of abundance) and diversity of flower flies could be influenced by green space predictors such as total surface and percentage of green areas, the quality of public squares and parks indices and greenness index (NDVI) across 34 municipalities in Greater Santiago. Furthermore, we described for the first time an interaction network exclusively for flower flies within the city. We analysed 1084 records and 607 interactions of 29 flower fly species. We found that the north‐east municipalities have more flower fly species. Based on the richness and abundance, the two‐way Jaccard analysis grouped the municipalities into three major clades: (a) those municipalities with more than 10 flower fly species, (b) those between five and 10 species and (c) those with fewer than five species. Generalised linear mixed models associated positively and significantly the flower fly richness, abundance and diversity, mainly with the quality of public squares and the mean NDVI value. The structure of our interaction network between flower flies and plant species showed low values for connectance and specialisation, but a significant value for interaction diversity. The quality of green spaces and NDVI information could help local decision‐makers improve the management of the municipality's green spaces, enhance the flower fly biodiversity inside the cities and provide potential ecosystem services such as pollination or pest control.

Rapid adaptation during invasion has historically been considered limited and unpredictable. We leverage whole-genome sequencing of >2600 plants across six continents to investigate the relative roles of colonization history and adaptation during the worldwide invasion of Trifolium repens. Introduced populations contain high levels of genetic variation with independent colonization histories evident on different continents. Five large structural variants on three chromosomes exist as standing genetic variation within the native range, and exhibit strong signatures of parallel climate-associated adaptation across continents. Common gardens in the native and introduced ranges demonstrate that three structural variants exhibit patterns of selection consistent with local adaptation across each range. Our results provide strong evidence that rapid and parallel adaptation during invasion is caused by large-effect structural variants introduced throughout the world. Significance Statement Biological invasions occur over short timescales and introductions are often hypothesized to include limited genetic diversity, making the role of adaptation in invasion success controversial. We demonstrate that the invasion of a human-commensal species, Trifolium repens, likely stems from multiple, diverse introductions with significant evidence of climate-associated adaptation following introduction. The genetic basis of adaptation is most strongly linked to five chromosomal rearrangements that each span hundreds of genes – matching theoretical predictions that large-effect variants are key to the initial stages of adaptation to novel environments. Chromosomal rearrangements have remarkably parallel signatures of adaptation across different introductions despite initial colonization from different areas of Europe. Our study highlights the impact of globalization and rapid adaptation for the invasion success of human commensal species.

Characterizing insect communities in pollinator-dependent crops helps determine the potential pollinator effectiveness and their effects on crop yield. Few studies have examined pollinator communities and their services to crops in South America. Furthermore, optimal sampling methods for these communities in the crop habitat have received little attention. Pan traps are one of the simplest and most widely used sampling methods to assess insect diversity. We compared different pan trap arrangements to describe potential pollinator communities in two commercial crops (blueberry and canola) in Southern Chile. We compared communities in the crops and assessed how sampling position (border or center) and pan trap color (blue, white, or yellow) affected sample composition. Species composition was significantly different between crops. Furthermore, trap color affected sample composition in blueberry, but trap position did not, whereas color had no significant effect on canola, but trap position did. In all cases, yellow pans captured the largest number of species. Hymenoptera explained most of the differences in sampling efficiency because of the differential responses across species. We suggest that pan trap assessments of the diversity in potential pollinator insects depend on crop characteristics, including planting configuration and floral morphology. Therefore, comparative studies should include pans of different colors positioned at various locations within the crop.