The diversity and abundance of wild insect pollinators have declined in many agricultural landscapes. Whether such declines reduce crop yields, or are mitigated by managed pollinators such as honey bees, is unclear. We found universally positive associations of fruit set with flower visitation by wild insects in 41 crop systems worldwide. In contrast, fruit set increased significantly with flower visitation by honey bees in only 14% of the systems surveyed. Overall, wild insects pollinated crops more effectively; an increase in wild insect visitation enhanced fruit set by twice as much as an equivalent increase in honey bee visitation. Visitation by wild insects and honey bees promoted fruit set independently, so pollination by managed honey bees supplemented, rather than substituted for, pollination by wild insects. Our results suggest that new practices for integrated management of both honey bees and diverse wild insect assemblages will enhance global crop yields.

Wild and managed bees are well documented as effective pollinators of global crops of economic importance. However, the contributions by pollinators other than bees have been little explored despite their potential to contribute to crop production and stability in the face of environmental change. Non-bee pollinators include flies, beetles, moths, butterflies, wasps, ants, birds, and bats, among others. Here we focus on non-bee insects and synthesize 39 field studies from five continents that directly measured the crop pollination services provided by non-bees, honey bees, and other bees to compare the relative contributions of these taxa. Non-bees performed 25-50% of the total number of flower visits. Although non-bees were less effective pollinators than bees per flower visit, they made more visits; thus these two factors compensated for each other, resulting in pollination services rendered by non-bees that were similar to those provided by bees. In the subset of studies that measured fruit set, fruit set increased with non-bee insect visits independently of bee visitation rates, indicating that non-bee insects provide a unique benefit that is not provided by bees. We also show that non-bee insects are not as reliant as bees on the presence of remnant natural or seminatural habitat in the surrounding landscape. These results strongly suggest that non-bee insect pollinators play a significant role in global crop production and respond differently than bees to landscape structure, probably making their crop pollination services more robust to changes in land use. Non-bee insects provide a valuable service and provide potential insurance against bee population declines.unmanaged pollinator | insect pollinator | fly | bee | beetle

Ecological intensification, or the improvement of crop yield through enhancement of biodiversity, may be a sustainable pathway toward greater food supplies. Such sustainable increases may be especially important for the 2 billion people reliant on small farms, many of which are undernourished, yet we know little about the efficacy of this approach. Using a coordinated protocol across regions and crops, we quantify to what degree enhancing pollinator density and richness can improve yields on 344 fields from 33 pollinator-dependent crop systems in small and large farms from Africa, Asia, and Latin America. For fields less than 2 hectares, we found that yield gaps could be closed by a median of 24% through higher flower-visitor density. For larger fields, such benefits only occurred at high flower-visitor richness. Worldwide, our study demonstrates that ecological intensification can create synchronous biodiversity and yield outcomes.

The genus Aristolochia presents conserved features in its basic structural plan of trap flowers and in its pollination syndrome. Visitors, usually flies, are attracted to the rotting-meat scented flowers and remain trapped until the second day, when the protogynous flowers release them. Aristolochia gigantea Mart. and Zucc showed many of these floral traits but display a citronella-like odour, giving the opportunity to study the reproductive ecology in this atypical species. Characteristics and behavior of pollinators, coupled with the distances between individual plants and populations, are important factors in patterns of genetic diversity. Thus, our objectives were to study the flower visitors, reproductive success, and gene flow in A. gigantea in the Chapada Diamantina, Bahia, Brazil. Results suggest that pollination by flies remains as a conserved interaction within the genus Aristolochia. The main pollinators appeared to be Megaselia spp. (Phoridae), evidenced primarily by the frequency of their occurrence within flowers and the transference of compatible pollen. On the other hand, the moderate to low levels of intrapopulation genetic variability found in A. gigantea, combined with low effective pollination and its reproductive dependence on biotic vectors, indicate that this species may be suffering gene erosion in the remaining populations located at Chapada Diamantina.Résumé : Le genre Aristolochia comporte des particularités conservées dans son plan structural de base de fleurs pièges et dans son syndrome de pollinisation. Les visiteurs, habituellement des mouches, sont attirés vers les fleurs à odeur de viande pourrie et demeurent piégées pendant deux jours, avant que les fleurs protogynes les relâchent. L'Aristolochia gigantea Mart. et Zucc montre plusieurs de ces traits floraux, mais dispense une odeur rappelant la citronnelle, ce qui ouvre la possibilité d'étudier l'écologie reproductive de cette espèce atypique. Les caractéristiques et le comportement des pollinisateurs, couplées avec les distances entre les plantes individuelles et les populations, constituent d'importants facteurs pour le patron de diversité génétique. Ainsi, les objectifs du groupe ont consisté à étudier les visiteurs des fleurs, le succès reproductif et le flux de gènes chez l'A. gigantea, dans la région de Chapada Diamantina, Bahia, au Brésil. Les résultats suggèrent que la pollinisation par les mouches fait l'objet d'une interaction conservée dans le genre Aristolochia. Les principaux pollinisateurs semblent appartenir au genre Megaselia (Phoridae), ce que supporte principalement la fréquence de leur présence dans les fleurs ainsi que le transfert de pollen compatible. En plus, le degré faible à modéré de variabilité génétique intrapopulation retrouvé chez l'A. gigantea, combiné avec le faible degré réel de pollinisation ainsi que sa dépendance reproductive sur des vecteurs biotiques, indique que cette espèce pourrait souffrir d'une érosion génétique chez les populations résiduelles du Chapada Diamantina.

Apesar da manga (Mangifera indica L.) ser uma fruteira amplamente cultivada nas regiões tropicais com alto valor econômico, ainda há muitas lacunas no conhecimento acerca de sua biologia e ecologia da polinização, que podem levar a um manejo inadequado e perda na produtividade. Nesse contexto, o presente estudo visa contribuir para a redução dessas lacunas ao investigar aspectos da morfologia e biologia floral, sistemas sexuais, mecanismos de polinização e potenciais polinizadores da variedade Tommy Atkins, na Bahia. As investigações foram realizadas no vale do São Francisco, no município de Juazeiro, maior pólo de fruticultura tropical do país. A manga é uma espécie andromonóica com flores heteromorfas, sendo as monoclinas maiores que as estaminadas. A longevidade floral de três dias permite que a planta disponibilize néctar a uma grande diversidade de visitantes. Na base das inflorescências, as flores estaminadas encontram-se em maior número, sugerindo a viabilidade da polinização por gravidade. A variedade se apresentou apomítica e sem barreiras para a autopolinização, contudo devido ao alto índice de aborto, sugere-se que a polinização cruzada, mediada por vetores de pólen, seja favorecida. Dentre os visitantes florais os potenciais polinizadores são moscas, devido, principalmente, à convergência funcional entre a morfologia das flores da manga e do aparelho bucal desses insetos. Palavras-chave: Mangifera indica; biologia floral; visitantes florais. ABSTRACT MANGO POLLINATION (Mangifera indica L.-ANACARDIACEAE) TOMMY ATKINS VARIETY, AT SÃO FRANCISCO VALLEY, BAHIA. Although mango (Mangifera indica L.) is widely distributed crop in tropical regions with great economic importance, there are still many gaps in knowledge about its pollination biology and ecology, which can lead to inadequate management and consequent loss in productivity. In that context, this study will contribute to reduce these gaps by investigating the morphology and floral biology, sexual systems, pollination mechanisms and potential pollinators of the variety Tommy Atkins, in Bahia. The investigation was developed at the São Francisco valley, Juazeiro, Bahia, the largest center for tropical fruit in the country. Mango is an andromonoic specie with heteromorphic flowers, the bisexual ones are larger than the staminate. The three days longevity provides nectar to a wide variety of visitors. At the base of the inflorescences, the staminate flowers are found in greater numbers, suggesting the viability of pollination by gravity. This variety is apomictic and has no barriers to self-pollination. However due to the high rate of abortion, it is suggested that cross-pollination, mediated by pollen vectors, is favored. Among the flower visitors the potential pollinators are flies, mainly due to the convergence between the functional morphology of the flowers of mango and the mouthparts of these insects.

Seventy five percent of fruit production of the major global crops benefit from insect pollination. Hence, there has been increased interest in how global change drivers impact this critical ecosystem service. Because standardized data on crop pollination are rarely available, we are limited in our capacity to understand the variation in pollination benefits to crop yield, as well as to anticipate changes in this service, develop predictions, and inform management actions. Here, we present CropPol, a dynamic, open and global database on crop pollination. It contains measurements recorded from 189 crop studies, covering 3,216 field observations, 2,421 yield measurements (i.e. berry weight, number of fruits and kg per hectare, among others), and 46,262 insect records from 49 commercial crops distributed around the globe. CropPol comprises 32 of the 87 leading global crops and commodities that are pollinator dependent. Malus domestica is the most represented crop (25 studies), followed by Brassica napus (22 studies), Vaccinium corymbosum (13 studies), and Citrullus lanatus (12 studies). The most abundant pollinator guilds recorded are honey bees (33.12% counts), bumblebees (18.65%), flies other than Syrphidae and Bombyliidae (13.76%), other wild bees (13.51%), beetles (11.47%), Syrphidae (4.86%), and Bombyliidae (0.06%). Locations comprise 32 countries distributed among European (70 studies), Northern America (59), Latin America and the Caribbean (27), Asia (22), Oceania (10), and Africa (7). Sampling spans three decades and is concentrated on 2001-05 (21 studies), 2006-10 (38), 2011-15 (87), 2016-20 (40). This is the most comprehensive open global data set on measurements of crop flower visitors, crop pollinators and pollination to date and we encourage researchers to add more datasets to this database in the future. No copyright restrictions are associated with the use of this dataset. Please cite this data paper when the data are used in publications and cite individual studies when appropriate.

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Males of some groups of bees have to find a place outside the nests to sleep, sometimes forming “male sleeping aggregations”. Here we report the first record of “dense” male sleeping aggregation of two different genera of Eucerini bees observed in Bahia, Brazil. We discuss the possible aim of this kind of aggregation as well the plant utilized on aggregate.