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The ecological aspects, distribution, and possible conservation of a syrphid hoverfly, Axona chalcopyga (Wiedemann, 1839) is poorly known due to their rare records. Three female individuals of A. chalcopyga were discovered in the Gelam forests of Terengganu state, which is the first record in Peninsular Malaysia. Here, we provided a pictorial description of the female. We also noted the functional role of the hoverfly as a potential pollinator candidate for the Gelam trees by visiting its flowers. [ABSTRACT FROM AUTHOR]

The ecological aspects, distribution, and possible conservation of a syrphid hoverfly, Axona chalcopyga (Wiedemann, 1839) is poorly known due to their rare records. Three female individuals of A. chalcopyga were discovered in the Gelam forests of Terengganu state, which is the first record in Peninsular Malaysia. Here, we provided a pictorial description of the female. We also noted the functional role of the hoverfly as a potential pollinator candidate for the Gelam trees by visiting its flowers.

Summary: Shifts in pollinator occurrence and their pollen transport effectiveness drive the evolution of mating systems in flowering plants. Understanding the genomic basis of these changes is essential for predicting the persistence of a species under environmental changes. We investigated the genomic changes in Brassica rapa over nine generations of pollination by hoverflies associated with rapid morphological evolution toward the selfing syndrome.We combined a genotyping‐by‐sequencing (GBS) approach with a genome‐wide association study (GWAS) to identify candidate genes, and assessed their functional role in the observed morphological changes by studying mutations of orthologous genes in the model plant Arabidopsis thaliana.We found 31 candidate genes involved in a wide range of functions from DNA/RNA binding to transport. Our functional assessment of orthologous genes in A. thaliana revealed that two of the identified genes in B. rapa are involved in regulating the size of floral organs. We found a protein kinase superfamily protein involved in petal width, an important trait in plant attractiveness to pollinators. Moreover, we found a histone lysine methyltransferase (HKMT) associated with stamen length.Altogether, our study shows that hoverfly pollination leads to rapid evolution toward the selfing syndrome mediated by polygenic changes. [ABSTRACT FROM AUTHOR]

The extent to which weeds in arable land are useful to pollinators depends in part on the temporal pattern of flowering and insect flight activity. We compiled citizen science data on 54 bees and hoverflies typical of agricultural areas in southern Sweden, as well as 24 flowering weed species classified as pollinator‐friendly in the sense that they provide nectar and/or pollen to pollinators. The flight periods of the bees and hoverflies varied greatly, but there were also some consistent differences between the four groups studied. The first group to fly were the early flying solitary bees (7 species), followed by the social bees (18 species). In contrast, other solitary bees (11 species) and hoverflies (22 species) flew later in the summer. Solitary bees had the shortest flight periods, while social bees and hoverflies had longer flight periods. Flowering of weed species also varied greatly between species, with weeds classified as winter annuals (e.g., germinating in autumn) starting early together with germination generalists (species that can germinate in both autumn and spring). Summer annuals (spring germinators) and perennials started flowering about a month later. Germination generalists had a much longer flowering period than the others. Weekly pollinator records were in most cases significantly explained by weed records. Apart from early flying solitary bees, all models showed strong positive relationships. The overall best explanatory variable was the total number of weeds, with a weight assigned to each species based on its potential as a nectar/pollen source. This suggests that agricultural weeds in Sweden provide a continuous potential supply of nectar and pollen throughout the flight season of most pollinators. [ABSTRACT FROM AUTHOR]

A diverse assemblage of insect visitors can provide functional complementarity within plant pollination due to differences in characteristics such as their physical traits, visitation rate and foraging time of day or year. In a horticultural context, greater functional complementarity may play a crucial role in enhancing fruit yield and quality by improving pollination. We tested whether the identity of the crop pollinators (bumblebee Bombus terrestris and hoverfly Eupeodes corollae) independently and additively influenced commercial strawberry yield, quality, and nutritional parameters such as vitamin C and sugar concentration. Fragaria x ananassa “Malling Champion” plants received pollination treatments of either a) “control”: self-pollination where pollinators were excluded, b) “bee”: bumblebee Bombus terrestris, c) “hoverfly”: Eupeodes corollae, d) “combined”: both B. terrestris and E. corollae. Hoverflies and bumblebees exhibited distinct visitation patterns throughout the day, establishing a functional complementary relationship that enhances pollination success and crop output as well as vitamin C concentrations. Strawberries from plants receiving pollination by bumblebees, or bumblebees and hoverflies combined, had higher yields of higher marketable quality. They also had measurably higher vitamin C content than strawberries from plants pollinated by hoverflies alone, or the control (self-pollinating) plants. This study advances our understanding of niche complementarity and its impact on fruit yield and quality. By elucidating the behavioural and temporal dynamics of pollinators, we provide valuable insights for optimizing pollination strategies in agricultural contexts. Our findings highlight the significance of behavioural factors, such as handling time and number of visits, in determining fruit quality.

Merodon triangulum Vujić, Radenković & Hurkmans, 2020 is a European endemic hoverfly species belonging to Merodon constans species-group, inside albifrons-lineage. The distribution of this species is known to be mostly central Europe and Balkan peninsula and it has been categorized as Near Threatened in the European IUCN red list of hoverflies; this paper cites the species for the first time in Ukraine (western Ukraine, specifically). In the present study, the preimaginal stages of this species are described and figured using Scanning Electron Microscopy. The material used for the descriptions were larvae collected in Ukraine and Serbia feeding inside underground storage organs of the spring snowflake Leucojum vernum L., 1753. This morphological description constitutes the first one inside the constans species-group, and the sixth description of the albifrons-lineage, in which there is only one species-group left to have at least one species of the preimaginal stages described (i.e., ruficornis species-group). The descriptions were compared with the rest available of the genus, stating the diagnostical characters of the present species and the shared characters inside the lineage. The novel information provided on the trophic interaction between M. triangulum larvae and Leucojum bulbs is stated for the first time and further supports the association of the constans species-group with the underground storage organs of snowflakes and snowdrops (Galantheae) in their role as host plants. [ABSTRACT FROM AUTHOR]

Simple Summary: Hoverflies, also known as flower flies, are a highly diverse group of two-winged flies with more than 6000 known species worldwide. This group of insects plays an important role in ecosystems, providing services such as plant pollination and pest control, among others. Regarding Eumerus, this hoverfly genus is one of the most speciose in the Palaearctic region, where new species are continually being discovered. Nevertheless, the great morphological variability of some species makes their identification and classification difficult. Therefore, the main aim of the present work was to assess the variability of the species of the Eumerus barbarus group in the western Mediterranean area under an integrative study (i.e., combining different techniques and data sources). We found high levels of morphological and genetic variability in two species of this group. Based on our findings, we described a new species from the island of Sardinia and provided the most comprehensive identification key for the males of this Eumerus species group from the western Mediterranean. Comprising nearly 300 described species, Eumerus Meigen, 1822, is one of the most speciose syrphid genera worldwide, and its taxonomic diversity is remarkable in the Mediterranean basin. The Eumerus barbarus (Coquebert, 1804) group consists of four species in the western Mediterranean. Although the phenotypic variability of this species group has been commented on in previous studies, it has never been contrasted with molecular data. In the present work, the morphological variation found in 300+ specimens of this species group from the western Mediterranean is explored and tested against the COI mitochondrial DNA (mtDNA). The highest phenotypic disparity was found in E. barbarus and Eumerus sulcitibius Rondani 1868. The integrative approach has not revealed cryptic diversity within the species E. barbarus but in E. sulcitibius. As a result, a new species close to E. sulcitibius was discovered, Eumerus sardus Aguado-Aranda, Ricarte & Hauser sp. n., from Sardinia, Italy. The new insular species is here described, illustrated, and discussed. A total of twenty-three haplotypes of COI mtDNA were identified amongst the analyzed Mediterranean specimens of E. barbarus, whereas two and five haplotypes were distinguished in the Iberian specimens of E. sulcitibius and Eumerus gibbosus van Steenis, Hauser & van Zuijen, 2017, respectively. Moreover, the first known barcodes of E. gibbosus and Eumerus schmideggeri van Steenis, Hauser & van Zuijen, 2017 were obtained, and the distribution ranges of all species are mapped. An updated dichotomous key to the males of the E. barbarus group from the western Mediterranean is provided. [ABSTRACT FROM AUTHOR]

Abstract The extent to which weeds in arable land are useful to pollinators depends in part on the temporal pattern of flowering and insect flight activity. We compiled citizen science data on 54 bees and hoverflies typical of agricultural areas in southern Sweden, as well as 24 flowering weed species classified as pollinator‐friendly in the sense that they provide nectar and/or pollen to pollinators. The flight periods of the bees and hoverflies varied greatly, but there were also some consistent differences between the four groups studied. The first group to fly were the early flying solitary bees (7 species), followed by the social bees (18 species). In contrast, other solitary bees (11 species) and hoverflies (22 species) flew later in the summer. Solitary bees had the shortest flight periods, while social bees and hoverflies had longer flight periods. Flowering of weed species also varied greatly between species, with weeds classified as winter annuals (e.g., germinating in autumn) starting early together with germination generalists (species that can germinate in both autumn and spring). Summer annuals (spring germinators) and perennials started flowering about a month later. Germination generalists had a much longer flowering period than the others. Weekly pollinator records were in most cases significantly explained by weed records. Apart from early flying solitary bees, all models showed strong positive relationships. The overall best explanatory variable was the total number of weeds, with a weight assigned to each species based on its potential as a nectar/pollen source. This suggests that agricultural weeds in Sweden provide a continuous potential supply of nectar and pollen throughout the flight season of most pollinators.

One of the largest families of the order Diptera - hoverflies, are at the same time one of the most prominent insect groups, being recognized as the second most important pollinator group, bioindicator species, as well as potential biocontrol agents. Thus, raising interest in their distribution, biology and ecology is not surprising. As a contribution to the process of systematizing knowledge on these species, in this paper there are pre­sented details on the fauna of hoverflies of the eastern part of Serbia. It was done by incor­porating information on so far published findings, older, but unpublished records, as well as records collected in recent field trips across 109 localities in Eastern Serbia, all in one place. The most significant findings are Cheilosia subpictipennis Claussen, 1998 and Paragus kopdagensis Hayat & Claussen, 1997, published for the first time for Serbia, and 105 species registered for Eastern Serbia for the first time. Additionally, one potentially new hoverfly species for science is registered: Paragus aff. testaceus.

This study focuses on the avidus–nigritarsis lineage within the genus Merodon, exploring morphological, genetic, and distributional aspects of two related assemblies within this lineage: the clavipes and pruni species groups. An integrative taxonomic approach was followed to ensure comprehensive species identification and validation, using adult morphology, wing geometric morphometrics, and genetic analysis of the mtDNA COI gene. In the clavipes group, seven species were identified, including three new species: M. aenigmaticus Vujić, Radenković & Likov, sp. nov., M. latens Vujić, Radenković & Likov, sp. nov., and M. rufofemoris Vujić, Radenković & Likov, sp. nov. In the pruni group, our revision revealed a new species, M. aequalis Vujić, Radenković & Likov, sp. nov., and the revalidation of Merodon obscurus Gil Collado, 1929, stat. rev. Merodon pallidus Macquart, 1842 is redescribed. Diagnoses, identification keys to species, and distribution maps are provided, and neotypes for Syrphus clavipes Fabricius, 1781 and Merodon quadrinotatus (Sack, 1931) are designated. Additionally, the following new synonyms are proposed: M. clavipes albus syn. nov., M. clavipes ater syn. nov., M. clavipes niger syn. nov., and M. splendens syn. nov. are junior synonyms of M. clavipes; and M. velox armeniacus syn. nov. and M. velox anathema syn. nov. are junior synonyms of M. velox. [ABSTRACT FROM AUTHOR]

This study was conducted in the provinces Antalya, Afyonkarahisar, Burdur, Isparta, and Konya, located in the Lakes Region of Turkey. Adults of Syrphidae were collected in the period between April and October 2014–2016, at least twice a season. In total 113 species belonging to three subfamilies and 39 genera were identified using morphological methods. Among them, four species are new to science and awaiting description, and 11 species recorded for the first time for the Turkish fauna. Identification keys with illustrations for the genera and species are provided. [ABSTRACT FROM AUTHOR]

Simple Summary: In this paper, the Merodon avidus (Diptera, Syrphidae) species complex was revised, whereupon we discovered and described four new species for science. An integrative taxonomy approach was used to delimit species boundaries. The molecular analysis, the differences in the shape of the wings, the morphological characters of the adults and the distribution ranges successfully separated all species from the complex. In this paper, the Merodon avidus (Diptera, Syrphidae) species complex was revised, whereupon we discovered and described four new species for science: Merodon atroavidus Vujić, Radenković et Likov sp. nov., M. magnus Vujić, Kočiš Tubić et Ačanski sp. nov., M. nigroscutum Vujić, Radenković et Likov sp. nov. and M. pseudomoenium Vujić, Kočiš Tubić et Ačanski sp. nov. An integrative taxonomy approach was used to delimit species boundaries. Two molecular markers (the mitochondrial COI gene and nuclear 28S rRNA gene—newly analysed marker for the complex) and geometric morphometry of the wing shape, together with morphological data and distribution, successfully separated all species from the complex. The morphological variability of the analysed species is described and discussed and an illustrated diagnostic key for typical morpho-forms of species from the M. avidus complex is presented. A distribution map of all investigated species from the complex is provided. The level of endemicity of the M. avidus complex was discussed. [ABSTRACT FROM AUTHOR]

Grassland management under local-scale results-based agri-environmental payment schemes (RBAPSs) are designed to benefit some biodiversity groups like plants. However, it is unknown if RBAPSs affect plant-pollinator interaction networks, and whether local or landscape management is more influential. Most studies focus on traditional community structure measures like richness, neglecting the impacts management may have on network structure and stability, and thereby ecosystem function. Plant species that benefit from RBAPSs could also act as key forage plants for pollinators, but this has not been investigated.We sampled networks across 23 grasslands in the West of Ireland to investigate if grassland management at local (RBAPS) and/or landscape scale (proportion of semi-natural grassland) influence network size, connectance, nestedness, linkage density and specialization of networks. Species strength analysis was used to identify key plant species for bumblebees, solitary bees, hoverflies, and butterflies.Results indicate RBAPSs benefit network size and linkage density, where species-rich grasslands supported larger networks and higher linkage densities. Networks surrounded by higher proportions of semi-natural grassland also had larger network sizes and higher linkage densities. Nestedness was greater in landscapes with high proportions of improved grassland. Key plant species differed between pollinator groups.Our results highlight that managing grasslands to promote greater plant diversity through a local scale RBAPS positively influences the structure and stability of networks, with possible implications for pollination service delivery. However, networks are also influenced by landscape management suggesting that local-scale management by itself may not be sufficient to conserve networks. We conclude that measures aimed at pollinators should include grassland management at both spatial scales where possible and to promote the establishment of key plant species to help sustain a wider range of pollinator taxa.

Background and Aims Sexual polymorphisms of flowers have traditionally been interpreted as devices that promote cross-pollination, but they may also represent adaptations for exploiting particular pollination niches in local environments. The cross-pollination function of enantiostyly, characterized by flowers having either left- or right-deflected styles, has been uncertain in some lineages, such as the Haemodoraceae, because the positioning of stamens and styles is not always completely reciprocal among morphs. Methods We examined the floral biology of populations of the poorly known species Barberetta aurea (Haemodoraceae) across its native range in South Africa to establish the general features of its enanatiostylous reproductive system and the agents and mechanism of pollen transfer. Results We confirmed that B. aurea has a system of dimorphic enantiostyly. Style morph ratios varied among populations sampled, but with an overall tendency to being equal. Crossing experiments demonstrated that B. aurea is fully self-compatible, that intra- and inter-morph crosses are equally fertile and that it is wholly dependent on pollinator visits for seed production. Pollination is mainly by syrphid flies that transfer the sticky pollen via their wings, which contact the anthers and stigma precisely as they hover during approach and feeding. The majority of syrphid fly visitors feed on a film of highly concentrated nectar situated at the base of ultraviolet-absorbent 'nectar guides'. Because one of the three stamens is deflected in the same direction as the style, we predicted a high likelihood of intra-morph pollination, and this was corroborated by patterns of transfer of coloured dye particles in cage experiments involving syrphid flies. Conclusions Barbaretta aurea exhibits dimorphic enantiostyly and, in contrast to most enantiostylous species, which are pollinated by bees, its flowers are specialized for pollination by syrphid flies. The lack of complete reciprocity of the enantiostylous arrangement of sexual organs facilitates both inter- and intra-morph pollen transfer on the wings of these flies. [ABSTRACT FROM AUTHOR]

Syrphid flies (Diptera, Syrphidae) play important ecological roles as pollinators, pest control agents, and decomposers. Communities are influenced by environmental variables such as land use. However, these interactions are poorly studied in urban landscapes. We used pan traps in community gardens, cemeteries, and parks in Montreal, Canada, to investigate syrphid fly communities in an urban landscape and describe how site surface area and heat island cover shape these communities. We estimated the species richness of communities and the occupancy patterns of three syrphid functional groups (insectivores, terrestrial saprophagous, and aquatic saprophagous). We captured 1,791 specimens from 48 species. Species richness increased with site surface area but did not vary with the level of urbanisation. The occupancy of the three groups did not change with site surface area. Syrphid flies of the terrestrial saprophagous group were less likely to occur on sites with high urbanisation, but the occupancy of insectivore and aquatic saprophagous groups did not vary with the variable. Implications for insect conservation Our results highlight that cities can harbour diversified syrphid fly communities and that certain functional groups are tolerant to urbanisation pressures. Our study suggests that conservation measures targeting syrphid flies in cities must be adapted to functional traits and larval requirements. [ABSTRACT FROM AUTHOR]

Detection of morphologically indistinguishable cryptic species implies using an integrative taxonomic approach with a combination of molecular, contemporary morphological, ecological and other relevant analyses. Within a contemporary morphological analysis, two approaches are commonly used in hoverfly taxonomy: a geometric morphometric analysis of the wing and surstyle shape. Here, the importance of the R4+5 vein shape is tested in cryptic species delimitation within four Merodon species groups using linear and semilandmark geometric morphometric analyses. As expected, geometric morphometrics showed a stronger resolution compared to linear morphometrics. Linear morphometrics failed to detect differences related to sexual dimorphism or differences among the species M. pruni and M. obscurus. However, all cryptic species and sexes were separated with high significance based on the R4+5 vein shape. Moreover, obtained results concurred with the landmark-defined wing shape and molecular results published in previous studies. Additionally, combining two characters, the semilandmark R4+5 vein shape and the landmark-defined wing shape, provided more detailed and precise insights into the shape differences. Our results showed that the R4+5 vein shape stands out as an important character in species delimitation of hoverflies where the sinuation of this vein is present. Therefore, it can be beneficial as a single character or in combination with a landmark-based wing shape analysis.

Monitoring pollinators is crucial for the evaluation of biodiversity and potential pollination services. Yet, efficiently monitoring multiple taxa over large areas can be costly. An alternative approach is using simple species bioindicators that represent the entire pollinator community. One of the requirements of a good bioindicator is that it can be easily identified to lower taxonomic levels and be sensitive to changes in habitat. This is the case for butterflies, a taxon for which many countries have a country-wide long-term monitoring scheme. We tested whether butterfly diversity can be used to predict diversity of bees and hoverflies both spatially and temporally. We surveyed 42 transects of the Dutch Butterfly Monitoring Scheme in 2020, to record species richness and abundance of butterflies, bees and hoverflies. We also recorded flower area and richness in the pollinator transects. To test whether pollinators with similar functional traits are more closely correlated than the entire pollinator community, we categorized bee and butterfly species according to their diet breadth (polyphagous vs. non-polyphagous), nitrogen-affinity (nitrophobous vs. nitrophilous larval resources) and body size. We used the same methods to test for temporal correlations over seven years for one site in Spain. Butterfly richness was not spatially correlated with bee richness (Pearson's r = 0.13), nor were the two taxa temporally correlated (Pearson's r = 0.02). Interestingly, hoverfly richness was spatially correlated with butterfly richness (Pearson's r = 0.43) and with bee richness (Pearson's r = 0.36) in the Netherlands and, hence, hoverflies might be slightly more suitable as a bioindicator of pollinator diversity in this area. Abundance of all three taxa showed no significant inter-correlation, except for correlations between diet specialist bees and butterflies (Pearson's r = 0.39). Importantly, all three taxa were strongly correlated with flower richness, but they varied in their preferences for host plant families. This is in line with 75% of the plant-pollinator studies finding significant positive relations. For monitoring schemes to be effective in informing better pollinator conservation, they should expand to include bees and hoverflies as well as simple indicators of habitat quality such as floral resources.

Intensively managed agricultural landscapes often lack suitable habitats to support diverse wildlife, particularly harming pollinator communities. Besides mass flowering crops, remnant patches of natural and semi‐natural vegetation may play a key role in maintaining and conserving biodiversity. Yet, the effects of different natural habitats, including forests and grasslands, on different pollinator communities are poorly understood at the landscape scale.We examined the abundance, richness, and diversity of wild bees and hoverflies, two key pollinator groups, across a land‐use gradient spanning forest edges, grassland, wildflower strips, and sunflower monoculture. We also examined the distribution of hoverfly larvae trophic guilds and wild bee nesting traits across the above‐mentioned land‐use gradient. Finally, we evaluated the impact of landscape structure (forest, grassland, and water cover in the surrounding landscape) on pollinator community composition.Our results indicate that forest and grassland habitats supported a higher abundance and greater richness of pollinators than wildflower strips and sunflower monocultures. Furthermore, hoverflies were more sensitive to habitat and floristic homogenization than wild bees. Sunflower and wildflower habitats also hosted a lower diversity of larvae trophic guilds and wild bee nesting guilds as compared to forests and grasslands.Our study suggests that conserving and restoring forest and grassland habitats within agricultural mosaics may serve as the main 'refuge' for wild pollinators. [ABSTRACT FROM AUTHOR]

Grassland management under local-scale results-based agri-environmental payment schemes (RBAPSs) are designed to benefit some biodiversity groups like plants. However, it is unknown if RBAPSs affect plant-pollinator interaction networks, and whether local or landscape management is more influential. Most studies focus on traditional community structure measures like richness, neglecting the impacts management may have on network structure and stability, and thereby ecosystem function. Plant species that benefit from RBAPSs could also act as key forage plants for pollinators, but this has not been investigated. We sampled networks across 23 grasslands in the West of Ireland to investigate if grassland management at local (RBAPS) and/or landscape scale (proportion of semi-natural grassland) influence network size, connectance, nestedness, linkage density and specialization of networks. Species strength analysis was used to identify key plant species for bumblebees, solitary bees, hoverflies, and butterflies. Results indicate RBAPSs benefit network size and linkage density, where species-rich grasslands supported larger networks and higher linkage densities. Networks surrounded by higher proportions of semi-natural grassland also had larger network sizes and higher linkage densities. Nestedness was greater in landscapes with high proportions of improved grassland. Key plant species differed between pollinator groups. Our results highlight that managing grasslands to promote greater plant diversity through a local scale RBAPS positively influences the structure and stability of networks, with possible implications for pollination service delivery. However, networks are also influenced by landscape management suggesting that local-scale management by itself may not be sufficient to conserve networks. We conclude that measures aimed at pollinators should include grassland management at both spatial scales where possible and to promote the establishment of key plant species to help sustain a wider range of pollinator taxa. [ABSTRACT FROM AUTHOR]

Currently, plant invasions affect native ecosystems across the Earth. Although much attention has already been paid to their effect on local communities, we still lack basic information on the associations between alien and local species. Here, we present the results of our survey of pollinators of the invasive plant Heracleum mantegazzianum (Apiaceae) in central Europe. At 20 sites within the westernmost part of the Czech Republic, which is strongly affected by the invasion of H. mantegazzianum, pollinators on the flowers of H. mantegazzianum were examined and compared to the species composition of pollinators on native vegetation in the surrounding area. While the flowers of H. mantegazzianum were frequently visited by high abundance of insects, the communities of H. mantegazzianum pollinators were relatively species poor, and the proportion of abundances of H. mantegazzianum pollinators was very uneven, with few species of generalist Diptera and the honey bee (Apis mellifera) dominating over all other flower visitors. Significantly larger species of the family Syrphidae visited flowers of giant hogweed than of other plants. Thus, giant hogweed is not a necessary part of flower communities for flower visiting insects, and it should be eradicated because of its negative effects on other plants, landscape and humans. Our results highlight the need for more detailed studies on direct interactions between alien plant species and native pollinator communities as well as indirect interactions between alien plants and native plants through competition for pollinators. [ABSTRACT FROM AUTHOR]

Abstract Flower strips have become a prevalent measure in agricultural landscapes to counteract biodiversity loss and especially promote pollinators. Although their benefits for pollinating insects have been frequently evaluated and reported, generalized conclusions about optimal settings for effective flower strips are still difficult. From the perspective of pollinators, flower strips vary distinctly in habitat quality, and the same applies for the control sites selected for scientific studies. In this study, we used a meta‐analytic approach based on a systematic review of recent studies (2009–2020) to analyze the relationship between flower strip effectiveness for pollinators and the contrast in habitat quality between flower strips and control sites. We extracted 350 data entries from 29 of 172 studies based on available data for richness or abundance of the pollinator taxa groups Apiformes, Lepidoptera and Syrphidae as response variables, for both flower strips and control treatments. All flower strips and control treatments were assigned a habitat quality score including information on spatial dimension, floral resources and management. Moreover, we included information on landscape complexity as measured by percent cover of seminatural habitats in the studied landscape. In general, our results of meta‐analytical models showed an increasing effect size of flower strips on pollinators for higher contrasts in habitat quality between flower strips and control treatments. This relationship was consistent across pollinator taxa and different levels of landscape complexity. Altogether, in terms of pollinator habitat quality, high‐quality flower strips were more attractive than low‐quality flower strips, and the reported effectiveness of flower strips decreased from low‐quality to high‐quality control treatments. We recommend that results of future studies evaluating flower strips for pollinators are always linked with the contrast in habitat quality between selected flower strips and control treatments.

Comprising nearly 300 described species, Eumerus Meigen, 1822, is one of the most speciose syrphid genera worldwide, and its taxonomic diversity is remarkable in the Mediterranean basin. The Eumerus barbarus (Coquebert, 1804) group consists of four species in the western Mediterranean. Although the phenotypic variability of this species group has been commented on in previous studies, it has never been contrasted with molecular data. In the present work, the morphological variation found in 300+ specimens of this species group from the western Mediterranean is explored and tested against the COI mitochondrial DNA (mtDNA). The highest phenotypic disparity was found in E. barbarus and Eumerus sulcitibius Rondani 1868. The integrative approach has not revealed cryptic diversity within the species E. barbarus but in E. sulcitibius. As a result, a new species close to E. sulcitibius was discovered, Eumerus sardus Aguado-Aranda, Ricarte & Hauser sp. n., from Sardinia, Italy. The new insular species is here described, illustrated, and discussed. A total of twenty-three haplotypes of COI mtDNA were identified amongst the analyzed Mediterranean specimens of E. barbarus, whereas two and five haplotypes were distinguished in the Iberian specimens of E. sulcitibius and Eumerus gibbosus van Steenis, Hauser & van Zuijen, 2017, respectively. Moreover, the first known barcodes of E. gibbosus and Eumerus schmideggeri van Steenis, Hauser & van Zuijen, 2017 were obtained, and the distribution ranges of all species are mapped. An updated dichotomous key to the males of the E. barbarus group from the western Mediterranean is provided.

In this paper, the Merodon avidus (Diptera, Syrphidae) species complex was revised, whereupon we discovered and described four new species for science: Merodon atroavidus Vujić, Radenković et Likov sp. nov., M. magnus Vujić, Kočiš Tubić et Ačanski sp. nov., M. nigroscutum Vujić, Radenković et Likov sp. nov. and M. pseudomoenium Vujić, Kočiš Tubić et Ačanski sp. nov. An integrative taxonomy approach was used to delimit species boundaries. Two molecular markers (the mitochondrial COI gene and nuclear 28S rRNA gene—newly analysed marker for the complex) and geometric morphometry of the wing shape, together with morphological data and distribution, successfully separated all species from the complex. The morphological variability of the analysed species is described and discussed and an illustrated diagnostic key for typical morpho-forms of species from the M. avidus complex is presented. A distribution map of all investigated species from the complex is provided. The level of endemicity of the M. avidus complex was discussed.

View on Scopus Six new species of the genus Eumerus Meigen, 1822 are here described from Iran. The new species and their four related groups are as follows: E. nadoosheni Gilasian & van Steenis sp. nov. of the Eumerus barbarus group; E. pollinipedes Gilasian & van Steenis sp. nov. of the Eumerus minotaurus group; E. effossus Gilasian & van Steenis sp. nov. and E. similis Gilasian & van Steenis sp. nov. of the Eumerus obliquus group, as well as E. intermedius Gilasian & van Steenis sp. nov. and E. khiabani Gilasian & van Steenis sp. nov. of the Eumerus ornatus group. In addition, the species E. argyropus Loew, 1848 and E. torsicus Grković & Vujić, 2015 are newly recorded from Iran. The illustrations of the male genitalia and images of the new species are provided.

The decline of pollinating insects in agricultural landscapes proceeds due to intensive land use and the associated loss of habitat and food sources. The feeding of those insects depends on the spatial and temporal distribution of nectar and pollen as food resource. Hence, to protect insect biodiversity, a spatio-temporal assessment of food quantity of their habitats is necessary. Therefore, sufficient data on traits of floral resources are required.As floral resources’ traits of plants are important to quantify food availability, we present two databases, the FloRes Database (Floral Resources Database) and the raw database, from where FloRes was derived. Both databases contain the plant traits: (1) flowering period, (2) floral-unit density per day, (3) nectar volume per floral unit per day, (4) sugar content per floral unit, (5) sugar concentration in nectar, (6) pollen mass or volume per floral unit and per day, (7) protein content of pollen and (8) corolla depth. All traits were sampled from literature and online databases. The raw database consists of 702 specified plant species, 138 unspecified species 37 species (spec., sp), 22 species pluralis (spp) and, for 79, only the genus was identified) and two species complexes (agg.). Those 842 taxa belong to 488 genera and 102 families. Finally, only 27 taxa have a complete set of traits, too few for a sufficient assessment of spatio-temporal availability of floral food-resources.As information on floral resources is scattered throughout many publications with different units, we also present our multistep workflow implemented in five consecutive R-scripts. The multistep workflow standardises the trait units of the raw database to comparable entities with identical units and aggregates them on a reasonable taxonomic level into the second application database, the FloRes Database. Finally, the FloRes Database contains aggregated information of traits for 42 taxa and, when corolla depth is excluded, for 72 taxa.This is the first attempt to gather these eight traits from different literature sources into one database with a multistep workflow. The publication of the multistep workflow enables the users to extend the FloRes Database on their own demands with other literature data or newly-gathered data to improve quantification of food resources. Especially, the combination of pollen, nectar and the open flowers per square metre is, as far as we know, a novelty.The FloRes Database can be used to evaluate the quantity of food-resource habitats available for pollinators, for example, to compare seed mixtures of agri-environmental measures, such as flower strips, considering flower phenology on a daily basis.

Considering the threat of pollinator decline to seriously affect ecosystem function and food security, the conservation of pollinating insects has become of utmost importance, entailing the accurate taxa identification in order to establish a long-term monitoring strategy. In addition to pollination service, hoverflies (Diptera: Syrphidae) also have a role as habitat bioindicators, as well as in organic matter recycling and protection of cultivated plants from pests. Representing one of the most species-rich hoverfly genera, Merodon Meigen, 1803 holds numerous taxonomic challenges, especially within the monophyletic Merodon ruficornis species group, which is characterized by incongruence between morphological and molecular data. In the present study, we successfully resolved the taxonomy of the M. ruficornis group using a combination of four genetic markers (3′ and 5′ ends of the COI gene, 28S and ITS2) and demonstrate their potential as molecular tools for resolving taxonomic questions within the Merodon genus. We proved the utility of indels as valuable molecular signals for the taxa delimitation within M. ruficornis group by performing two different indels schemes—(1) excluding indels from analysis as missing data; and (2) coding indels as presence/absence character matrix. In addition to the found congruence with morphologically defined species, our results revealed intraspecific differentiation between Anatolian and Balkan populations within three species—M. loewi, M. trebevicensis and M. armipes. According to the divergence time estimates, lineage diversification within the M. ruficornis group probably took place during Pleistocene climatic changes as a consequence of the species' range alterations. [ABSTRACT FROM AUTHOR]

This study highlights the potential of urban dry grasslands for diverse pollinator communities of wild bees and hoverflies, including rare and endangered species.By using pan trap sampling on 49 study sites distributed across the urban environment, responses of wild bee and hoverfly communities to urban features at two spatial scales (urban matrix and local habitat) were examined.A total of 1246 hoverfly individuals (Syrphidae) from 31 species and 1463 bee individuals (Apoidea) from 107 species were collected. Our analysis showed that hoverflies are impacted by urban matrix features and local floral resources, whereas wild bees only respond to patch size at the local habitat scale and endangered wild bee species additionally to non‐native pollinator‐friendly plants.Given the different responses of wild bees and hoverflies to the urban environment, we recommend multi‐taxon approaches for urban conservation practice. Urban dry grasslands and the diversity of pollinator‐friendly plants, including non‐native species, should be conserved and promoted to support urban pollinator diversity. [ABSTRACT FROM AUTHOR]

New studies by the Institute for Biodiversity Information e.V. (IfBI) on the biogas flowering fields with Veitshöchheim hemp mix show the outstanding importance of perennial flowering structures. They provide a clear answer to the role of the agricultural landscape for species conservation ("Can the agricultural landscape be a habitat for wild bees?", Mandery & Müller 2019). During flowering, 408 species of pollinators from the species groups of stinging flies, hoverflies and butterflies were found in these fields used as a substitute for corn, including the highly endangered "subterranean bumblebee" Bombus subterraneus, which is rarely found elsewhere. [ABSTRACT FROM AUTHOR]

In this paper, we revise the Merodon aberrans species group of the genus Merodon Meigen, 1803 (Diptera: Syrphidae), providing morphological diagnoses and descriptions, molecular data for three species, as well as an illustrated key and a discussion of the different taxonomic characters used. We also discuss distribution patterns for this species group. The results revealed that the M. aberrans group is composed of five described species (M. aberrans Egger, 1860, M. brevis Paramonov, 1926, M. flavitibius Paramonov, 1926, M. hamifer Sack, 1913, and M. warnckei Hurkmans, 1993) and three new ones, namely M. hermonensis Vujić, Radenković et Likov sp. nov., M. petiolatus Vujić, Radenković et Rojo sp. nov., and M. retectus Vujić, Radenković et Likov sp. nov. Following a detailed study of the type material in different entomological collections, the status of several species is revised, one new synonym is proposed (subspecies M. aberrans isperensis Hurkmans, 1993 as junior synonym of M. flavitibius), lectotypes are designated for M. kneri Mik, 1867 and M. flavitibius, and paralectotypes are designated for M. hamifer and M. flavitibius. Seven out of eight species from the M. aberrans group are distributed in the Asian continent, namely all Caucasian countries, Turkey and Iran, confirming the notion about high diversity of Merodon species in these regions, but also highlighting the need for a systematic faunistic research. [ABSTRACT FROM AUTHOR]

The study was conducted in south-eastern Poland, in three apple orchards where integrated pest management was applied, and in one ecological orchard and in their surroundings. In total, 1,677 individuals of Syrphidae belonging to 37 species, 21 genera, and two subfamilies were collected in the yellow traps. The most numerous were zoophagous syrphids - they constituted 94.5% of all the collected specimens and about 70% of the noted species. Among them, one species - Episyrphus balteatus (Deg.) - was the eudominant in the orchards and their surroundings. Comparing the occurrence of Syrphidae in the three IPM apple orchards and in their surroundings, it can be stated that more syrphids were caught in the boundary vegetation than within the orchards, whereas on the ecological site, more hoverflies were collected within the apple orchard than on the neigbouring plants. In most cases, in the orchard under IPM the syrphid species abundant in the surroundings of the orchards also appeared in great numbers in the orchards themselves, which indicated their movement from the boundaries into the orchards. The study has shown that the surroundings of orchards with species-rich, flowering plants positively influenced the species richness and the abundance of hoverflies occurring in the orchards. [ABSTRACT FROM AUTHOR]

Land use change has been identified as a cause for biodiversity loss and has significant effects on pollinators and their interactions with plants. Interaction network analyses complement diversity estimators by providing information on the stability and functionality of the plant-pollinator community in an ecosystem. However, how land use changes affect insect diversity, and the structure of their plant-insect interaction networks, could depend on the intensity of the disturbance but also may be a matter of scale. Our study was carried out in a tropical highland landscape dominated by intense, yet diverse, small-scale agriculture. We studied the effects of land use, at a landscape scale, and local cover and plant ecological descriptors, at a local scale; on diversity descriptors of insect pollinator communities, the abundance of the most frequent flower visitors, and their interaction networks. Seminatural vegetation favored insect flower visitors at both scales. At the landscape scale, human settlements positively influenced bee diversity, and seminatural areas favored the abundance of frequent hoverfly and bumblebee species. At the local scale, bare soil cover negatively influenced honeybee abundance while flower-rich covers positively related to bumblebee abundance. Only local scale variables had influence on network metrics. Bare soil cover was related to higher network specialization, probably due to a low rate of honeybee interactions. Flower-rich covers negatively influenced network connectance but favored modularity. These results suggest that flower resources, provided by weed areas and flowering crops, promote a high rate of interactions between trophic levels and a non-random structure in the interaction networks that may be helping to sustain network stability. Our results highlight the role of seminatural vegetation, at both scales, in maintaining stable insect pollinator communities and interactions in heterogeneous agricultural landscapes of the tropics.

We record Aristosyrphus carpenteri (Hull, 1945) for the first time from South America. This species was previously known from Panama and Costa Rica. New specimens, collected in Pichincha Province of Ecuador, represent the first reported occurrence of this flower fly genus from the country. Images, diagnosis, and DNA barcodes are provided to help with the identification of this species. [ABSTRACT FROM AUTHOR]

Aim: Aggregated species occurrence data are increasingly accessible through public databases for the analysis of temporal trends in the geographic distributions of species. However, biases in these data present challenges for statistical inference. We assessed potential biases in data available through GBIF on the occurrences of four flower‐visiting taxa: bees (Anthophila), hoverflies (Syrphidae), leaf‐nosed bats (Phyllostomidae) and hummingbirds (Trochilidae). We also assessed whether and to what extent data mobilization efforts improved our ability to estimate trends in species' distributions. Location: The Neotropics. Methods: We used five data‐driven heuristics to screen the data for potential geographic, temporal and taxonomic biases. We began with a continental‐scale assessment of the data for all four taxa. We then identified two recent data mobilization efforts (2021) that drastically increased the quantity of records of bees collected in Chile available through GBIF. We compared the dataset before and after the addition of these new records in terms of their biases and estimated trends in species' distributions. Results: We found evidence of potential sampling biases for all taxa. The addition of newly‐mobilized records of bees in Chile decreased some biases but introduced others. Despite increasing the quantity of data for bees in Chile sixfold, estimates of trends in species' distributions derived using the postmobilization dataset were broadly similar to what would have been estimated before their introduction, albeit more precise. Main conclusions: Our results highlight the challenges associated with drawing robust inferences about trends in species' distributions using publicly available data. Mobilizing historic records will not always enable trend estimation because more data do not necessarily equal less bias. Analysts should carefully assess their data before conducting analyses: this might enable the estimation of more robust trends and help to identify strategies for effective data mobilization. Our study also reinforces the need for targeted monitoring of pollinators worldwide. [ABSTRACT FROM AUTHOR]

Agricultural intensification is debated as one of the major drivers for the decline of insect biodiversity. Agri-environmental schemes (AES) are a common measure to promote biodiversity in agriculture by granting compensational payments to farmers for environmentally friendly practices. In this study we examined the effect of buffer strips of at least 5 m width, adjacent to small watercourses and drainage ditches, on insect biomass and insect species richness in agricultural landscapes. We selected ten arable fields in each of four regions in lower and upper Bavaria, Southern Germany. 25 out of 40 sites had a buffer strip between arable crops and watercourse. Insects were sampled at three time periods (May/June, June/July and August/September) for two weeks each. In each period two samples were collected (one per week). On each site Malaise traps were set up in 5 and 80 m distance to the embankment of the watercourse. Half of the samples was then subjected to metabarcoding and the other half was classified into different insect groups by morphological identification and the number of the individuals for each group was counted. For hoverflies (Syrphidae), individuals were identified at species-level. Data on vegetation structure (cover of grasses and herbs) in the studied riparian buffer strips was collected and correlated with number of species, abundances and biomass of flying insects. The five taxonomic orders with the highest species richness and individual numbers were: Diptera, Hymenoptera, Coleoptera, Lepidoptera and Hemiptera. Diptera dominated hereby with 34% of all species and 81% of all individuals. On average, mixed models indicated 31% higher insect biomass, 15% higher species richness and 29% higher individual numbers of flying insects in buffer strips at 5 m distance to the watercourse compared to sites with no buffer strip. The effect was even stronger for butterflies (32% higher species species richness, 70% more individuals) and hoverflies (24% higher species richness, 51% more individuals). In the presence of a buffer strip significantly higher numbers were found for total individuals, Diptera, Hymenoptera and Coleoptera. In 80 m distance to the watercourse, the samples of flying insects were not significantly influenced by a riparian buffer strip. This study highlights the importance of buffer strips in agricultural regions and their multifunctional potential in fostering biodiversity additionally to their acknowledged use for water protection. Ideally, buffer strips are rich in herbs and inflorescences and are therefore beneficial for the insect fauna by serving as valuable habitat with high potential connectivity at landscape level. • 31% higher biomass on average of flying insects in riparian buffer strips compared to agriculturally used fields. • 15% higher species richness on average of flying insects in riparian buffer strips compared to agriculturally used fields. • 29% higher individual numbers on average of flying insects in riparian buffer strips compared to agriculturally used fields. [ABSTRACT FROM AUTHOR]

Three new species of Myolepta Newman, 1838 are described from Thailand (M. iota sp. nov.), Laos (M. diaphora sp. nov.) and Indonesia (M. geras sp. nov. from Java), and new records of Myolepta petiolata Thompson, 1971 from Thailand are also provided. Diagnoses, illustrations and known distributional data are given. In addition, the generic affinities and subdivision of Myolepta are discussed based on these newly described taxa.

Research into pollinators in managed landscapes has recently combined approaches of pollination ecology and landscape ecology, because key stressors are likely to interact across wide areas. While laboratory and field experiments are valuable for furthering understanding, studies are required to investigate the interacting drivers of pollinator health and diversity across a broader range of landscapes and a wider array of taxa. Here, we use a network of 96 study landscapes in six topographically diverse regions of Britain, to test the combined importance of honeybee density, insecticide loadings, floral resource availability and habitat diversity to pollinator communities. We also explore the interactions between these drivers and the cover and proximity of semi-natural habitat. We found that among our four drivers, only honeybee density was positively related to wild pollinator abundance and diversity, and the positive association between abundance and floral resources depended on insecticide loadings and habitat diversity. By contrast, our exploratory models including habitat composition metrics revealed a complex suite of interactive effects. These results demonstrate that improving pollinator community composition and health is unlikely to be achieved with general resource enhancements only. Rather, local land-use context should be considered in fine-tuning pollinator management and conservation. This article is part of the theme issue 'Natural processes influencing pollinator health: from chemistry to landscapes'. [ABSTRACT FROM AUTHOR]

Gardens are important habitats for pollinators, providing floral resources and nesting sites. There are high levels of public support for growing 'pollinator‐friendly' plants but while plant recommendation lists are available, they are usually inconsistent, poorly supported by scientific research and target a narrow group of pollinators. In order to supply the most appropriate resources, there is a clear need to understand foraging preferences, for a range of pollinators, across the season within horticultural landscapes.Using an innovative DNA metabarcoding approach, we investigated foraging preferences of four groups of pollinators in a large and diverse, horticultural and agricultural landscape, across the flowering season and over 2 years, significantly improving on the spatial and temporal scale that can be achieved using observational studies.Bumblebees, honeybees, non‐corbiculate bees and hoverflies visited 191 plant taxa. Overall floral resources were shared between the different types of pollinators, but significant differences were seen between the plants used most abundantly by bees (Hymenoptera) and hoverflies (Diptera).Floral resource use by pollinators is strongly associated with seasonal changes in flowering plants, with pollinators relying on dominant plants found within each season, with preferences consistent across both years.The plants identified were categorised according to their native status to investigate the value of native and non‐native plants. The majority of floral resources used were of native and near‐native origin, but the proportion of horticultural and naturalised plants increased during late summer and autumn.Synthesis and applications. Plant recommendation lists for pollinators should distinguish between bees and hoverflies and provide evidence‐based floral recommendations throughout the year that include native as well as non‐native plants for use in the United Kingdom and Northern Europe. Specific management recommendations include reducing mowing to encourage plants such as dandelion Taraxacum officinale and buttercups Ranunculus spp., and reducing scrub management to encourage bramble Rubus fruticosus. [ABSTRACT FROM AUTHOR]

Simple Summary: Camellia oleifera is an important woody grain and oil plant worldwide. However, owing to a significant decline in the number of wild pollinators globally and the associated reduction in pollination services and seed production, camellia oil is in short supply. Therefore, it is important to evaluate the pollination mechanisms and efficiency of wild pollinators in C. oleifera seed production. We explored the pollination system of C. oleifera, focusing on the flower-visiting characteristics of its candidate pollinators. We found that Apis mellifera is the best candidate pollinator, but flies and hoverflies also play important roles in the pollination system. Camellia oleifera Abel. is an important woody oil plant, and its pollination success is essential for oil production. We conducted this study to select the best pollinator candidates for C. oleifera using principal component analysis and multi-attribute decision-making. Field observations of the flower-visiting characteristics of candidate pollinators were conducted at three sites. The insect species that visited flowers did not considerably differ between regions or time periods. However, the proportion of each species recorded did vary. We recorded eleven main candidates from two orders and six families at the three sites. The pollen amount carried by Apis mellifera was significantly higher than that of other insects. However, the visit frequency and body length of Apis mellifera were smaller than those of Vespa velutina. Statistical analysis showed that A. mellifera is the best candidate pollinator; Eristaliscerealis is a good candidate pollinator; Phytomia zonata, A. cerana, and V. velutina were ordinary candidate pollinators; and four fly species, Episyrphus balteatus, and Eristalinus arvorum were classified as inefficient candidate pollinators. Our study shows that flies and hoverflies play an important role in the pollination system. Given the global decline in bee populations, the role of flies should also be considered in C. oleifera seed production. [ABSTRACT FROM AUTHOR]

Cities are considered important refuges for insect pollinators. This has been shown repeatedly for wild bees, but may also be true for other diverse taxa such as hoverflies. However, our understanding of how urban environmental filters shape pollinator species communities and their traits is still limited. Here, we used wild bee and hoverfly species, communities and their functional traits to illustrate how environmental filters on the landscape and local scale shape urban species pools. The multi-taxon approach revealed that environmental filtering predominantly occurred at the landscape scale as urbanisation and 3D connectivity significantly structured the taxonomic and functional composition of wild bee (sociality, nesting, diet, body size) and hoverfly (larval food type, migratory status) communities. We identified urban winners and losers attributed to taxon-specific responses to urban filters. Our results suggest that insect pollinator conservation needs to take place primarily at the landscape level while considering species traits, especially by increasing habitat connectivity. [ABSTRACT FROM AUTHOR]

The identification of floral visitation by pollinators provides an opportunity to improve our understanding of the fine-scale ecological interactions between plants and pollinators, contributing to biodiversity conservation and promoting ecosystem health. In this review, we outline the various methods which can be used to identify floral visitation, including plant-focused and insect-focused methods. We reviewed the literature covering the ways in which DNA metabarcoding has been used to answer ecological questions relating to plant use by pollinators and discuss the findings of this research. We present detailed methodological considerations for each step of the metabarcoding workflow, from sampling through to amplification, and finally bioinformatic analysis. Detailed guidance is provided to researchers for utilisation of these techniques, emphasising the importance of standardisation of methods and improving the reliability of results. Future opportunities and directions of using molecular methods to analyse plant–pollinator interactions are then discussed. [ABSTRACT FROM AUTHOR]

Land‐use intensification is the main factor for the catastrophic decline of insect pollinators. However, land‐use intensification includes multiple processes that act across various scales and should affect pollinator guilds differently depending on their ecology. We aimed to reveal how two main pollinator guilds, wild bees and hoverflies, respond to different land‐use intensification measures, that is, arable field cover (AFC), landscape heterogeneity (LH), and functional flower composition of local plant communities as a measure of habitat quality. We sampled wild bees and hoverflies on 22 dry grassland sites within a highly intensified landscape (NE Germany) within three campaigns using pan traps. We estimated AFC and LH on consecutive radii (60–3000 m) around the dry grassland sites and estimated the local functional flower composition. Wild bee species richness and abundance was positively affected by LH and negatively by AFC at small scales (140–400 m). In contrast, hoverflies were positively affected by AFC and negatively by LH at larger scales (500–3000 m), where both landscape parameters were negatively correlated to each other. At small spatial scales, though, LH had a positive effect on hoverfly abundance. Functional flower diversity had no positive effect on pollinators, but conspicuous flowers seem to attract abundance of hoverflies. In conclusion, landscape parameters contrarily affect two pollinator guilds at different scales. The correlation of landscape parameters may influence the observed relationships between landscape parameters and pollinators. Hence, effects of land‐use intensification seem to be highly landscape‐specific. [ABSTRACT FROM AUTHOR]

Simple Summary: Hoverflies and bees play a key role in plant pollination. The increasing concern about pollinator reduction forces the planning of a sampling monitoring scheme to evaluate the change in the populations of these important insects. The present research provides baseline data about the distribution of hoverflies and bees in the Dolomiti Bellunesi National Park (Northeastern Italy). The hoverfly community shows a unimodal distribution with peak at middle elevation, while bees display a linear reduction in richness and abundance with increasing altitude. Both hoverfly and bee β-diversity at high altitude is dominated by species turnover more than by nestedness. Hoverflies (Diptera: Syrphidae) and bees (Hymenoptera: Anthophila) are two key taxa for plant pollination. In the present research, the altitudinal distribution of these taxa was studied along two gradients (elevation range: 780–2130 m) in the Dolomiti Bellunesi National Park (Northeastern Italy). Pan traps were used as a sampling device to collect both hoverflies and bees. Other than altitude, the effect of landscape complexity and plant diversity were considered as potential predictors of hoverfly and bee richness and abundance along the two gradients. A total of 68 species of hoverflies and 67 of bees were collected during one sampling year, confirming the efficacy of pan traps as a sampling device to study these taxa. Altitude was the main variable affecting both hoverfly and bee distribution. The two taxa show different distribution patterns: hoverflies have a unimodal distribution (richness and abundance) with peak at middle altitude (1500 m), while bees have a monotonic decline (richness and abundance) with increasing altitude. Both hoverfly and bee populations change with the increasing altitude, but the change in hoverflies is more pronounced than in bees. Species turnover dominates the β-diversity both for hoverflies and bees; therefore, the hoverfly and bee communities at higher altitudes are not subsamples of species at lower altitude but are characterized by different species. This poses important conservation consequences. Some rare species, typical of an alpine habitat were recorded; the present research represents important baseline data to plan a monitoring scheme aimed at evaluating the effect of climate change on pollinators in these fragile habitats. [ABSTRACT FROM AUTHOR]

Eristalinus aeneus (Scopoli) and Eristalis tenax (L.) (Diptera: Syrphidae, Eristalini) are important pollinator species that can be artificially reared and commercialised. To achieve better control over the pupal development time and adult emergence, cold storage techniques are suitable tools. Insects were reared under controlled conditions: 25 ± 1 °C, 50% r.h., and L12:D12 photoperiod. Pupae of both species were stored at 5 °C at the beginning (early treatments) or at the end (late treatments) of their development for various periods of time (5, 10, 15, 20, or 30 days). Development stopped completely at 5 °C in both treatments, but in general, pupae stored at the beginning of the pupal stage provided better results in terms of survival (adult emergence) and quality of the adults (general morphology). The cold tolerance of E. tenax was lower than that of E. aeneus, with their pupal developmental time successfully extended up to 18 and 23 days, respectively, without compromising survival and morphology. The number and types of morphological alterations due to cold storage were recorded. [ABSTRACT FROM AUTHOR]

Studies were conducted to broaden the current knowledge on seasonality, richness, abundance, and role of syrphids flies in the greenhouse pepper agroecosystem (GPA) in northwestern Argentina. In the GPA, a great richness (54 species) and abundance (517 individuals) of syrphids were found within Syrphinae (40 species; 443 individuals) and Eristalinae (14 species; 74 individuals) subfamilies. Besides, three species, Ocyptamus dimidiatus, O. gastrostactus and Toxomerus watsoni, were recorded for the first time in Argentina, and 12 species were recorded for the first time in Tucumán, expanding their geographical distribution to northwestern Argentina. Syrphid population tend to increase in spring and autumn. The environment occupation by different species showed remarkable differences since 41 were found in an open field, three in the greenhouse, and 10 in both environments. The richness and biodiversity were higher at the open field than in the greenhouse, however, these greenhouse species are important as biological control agents (BCA). Among them, the most abundant were Allograpta exotica, A. obliqua, T. duplicatus, Toxomerus sp. 1, O. dimidiatus and O. zoroaster, whose larvae were found feeding on pepper pests such as whiteflies and aphids. New plant-pest-predator associations were established, involving pepper, weeds, aphids, whiteflies, and syrphids. Four collection methods: Malaise trap, sweep net, infested plant tissues, and McPhail trap contributed to 59.2%, 70.4%, 8.6%, and 7.4% of total syrphid richness, respectively. Based on abundance, distribution in the GPA, and direct involvement in pepper pest control, A. exotica, A. obliqua, T. duplicatus, and Toxomerus sp.1 can be used as BCA for the control of whiteflies and aphids in GPA. [ABSTRACT FROM AUTHOR]

Roads and road verges can potentially have opposite impacts on organisms that move through the landscape. While road verges can be habitat for a large number of species, and have been proposed to act as dispersal corridors, roads can act as barriers to movement. This duality of roads and road verges has however rarely been assessed simultaneously, and it is unknown to what degree it depends on the amount of traffic on the road and on the habitat quality of the road verge. We used fluorescent powdered dye to track movements of flower‐visiting insects along roads with varying traffic intensity, and in verges with contrasting habitat quality (flowering plant species richness and flower density). Insect movements along road verges were more frequent than movements into the adjacent habitats, indicating that verges act as corridors. The frequency of movements that required crossing the road was lower compared to the frequency of movements that did not, suggesting that roads are barriers. The movement patterns were independent of traffic intensity, but the barrier effect was stronger when the road verge had a higher density of flower resources. The effect of roads as a barrier and of the road verges as corridors were independent of each other. Our results suggest that flower‐visiting insects tend to remain longer in road verges with high density of flowers and we therefore suggest that managing road verge habitats for an increased plant diversity will mitigate the known negative impacts of roads on insect populations. [ABSTRACT FROM AUTHOR]

The species Calaretropidia delmohardy Thompson, 2017 (Diptera: Syrphidae) is recorded from Sulawesi for the first time. The species was described based on a single male from Sentani, Papua Province, Indonesia. A short comment on this new record and habitus images are provided. [ABSTRACT FROM AUTHOR]