Pollinator Diversity Research Articles

The effect of land cover on the foraging behavior and pollen in the honey of the giant bee Apis dorsata in Sumatra

IntroductionApis dorsata, the common bee pollinator in tropical forests, is experiencing a population decrease due to several anthropogenic factors that lead to land cover changes and habitat loss. Land cover changes may alter their resource supply and foraging behavior. Our study aimed to determine foraging behavior and botanical origin using pollen of A. dorsata honey in two land cover types: plantationdominated landscape (PL) in Kampar (Riau) and forest-agriculture-dominated landscape (FL) in Kerinci (Jambi) Sumatra, Indonesia.MethodsWe observed two colonies of A. dorsata flight direction and flight activities in each land cover from 9 am–3pm. Honey was harvested from both nests of A. dorsata and the pollen in the honey was analyzed using acetolysis procedure. Vegetation analysis in both locations was conducted based on the flight directions of the giant honey bees.ResultsThe foraging data of A. dorsata showed a difference in the total number of bees between these two land cover types. The number of bees flying out and returning to the nest was higher in Kerinci than in Kampar, while high morning foraging activities were recorded in both land cover types. Furthermore, the foraging activity of the colonies in the PL landscape, i.e., flying out and returning to the nest with and without pollen, decreased at noon. The palynological results of the honey showed that in the PL landscape, pollen diversity was very low and mainly consisted of Elaeis gueneensis pollen (97%). Meanwhile, pollen types and concentrations were much higher in the FL than in the PL.DiscussionThis result suggests that A. dorsata exhibits a more varied foraging behavior in a diverse and heterogeneous landscape in Kerinci compared to a plantation-dominated habitat in Kampar.

Konservasi Kupu-Kupu Penting Sebagai Penyerbuk di Kampung Wisata Isyo Hills Rhepang Muaif Nimbokrang, Kabupaten Jayapura

Butterflies are an important example of pollinating insects of the Order Lepidoptera. The presence of butterfly pollinating insects in nature is highly dependent or influenced by the availability of flowering plants visited in the ecosystem. The purpose of this study was to determine the diversity and abundance of butterfly pollinator in flowering plants. A direct survey method (visual) with a radius of ± 100-250 m² was done with scan sampling technique. Parameters measured were the abundance and the species richness of butterflies visited flowering plants as well as the species richness of flowering plants visited by butterflies pollinator. The data obtained were analyzed using the the Shannon-Wiener diversity index (H’). The results showed that at study sites in secondary forest habitats and yards, 25 species of butterfly pollinators were found consisting of 5 families with 308 individuals. Nine species of flowering plants visited by butterfly pollinators. The Jatropha integerrima was the most visited by butterfly pollinators with 11 species, followed by Hibiscus rosa-sinensis and Ixora coccinea (9 species), Clerodendron paniculatum (6 species), Mussaenda ralateensis (4 species), Bidens pilosa and Celosia argentea (3 species), Zinnia elegans visited by 2 species and Portulaca oleracea visited by 1 species of butterfly pollinators. Based on the calculation, the value of Shannon-Wiener index (H') is 2.946, which indicates that the level of diversity of butterfly pollinators in the medium category.

The Establishment of the Agricultural Landscape of Central Sicily Between the Middle Neolithic and the Beginning of the Iron Age

The possible co-variation of human occupation and vegetation from the Middle Neolithic to the beginning of the Iron Age (7.5–2.8 ka BP) in Central Sicily in the context of the central Mediterranean between Middle and Late Holocene are analysed in this paper to provide new insights on Sicilian prehistoric demography. The demographic and economic trends during these millennia were reconstructed using archaeological, Accelerator Mass Spectrometry 14C dates, palynological, archaeobotanical, and zooarchaeological data from the northern, central, and southern sectors of Central Sicily through a diachronic comparison with variation in Arboreal Pollen, Anthropogenic Pollen Indicators, Olea-Juglans-Castanea pollen, microcharcoals, and Sporormiella from four pollen cores from sites in different ecosystems. A very significant spread of farming activities was found at the end of the Neolithic, together with an apparent demographic gap during the Middle Copper Age, and the emergence of agricultural landscapes at the end of the Copper Age associated with a striking increase in population. A combination of cultural and climatic changes during the late phase of the Bronze Age resulted in a subsequent overall decrease in population.

Pollinators diversity and pollination effects on yield attributes of sunflower (Helianthus annuus Linnaeus) in Odisha, India

In the study on the diversity of pollinators and their pollination efficiency in sunflower (Helianthus annuus L.) under field condition of Odisha during 2021-22, recorded 18 species of pollinators. Indian honeybee, Apis cerana indica F. (Hymenoptera, Apidae) was found to be the major one among the insect pollinators. The experiment conducted for two years with three different treatments viz., open pollination (OP), managed A. cerana indica pollination (HB) and pollinator exclusion (PE) for better yield and quality revealed that both quantitative and qualitative parameters were significantly higher in OP sunflower crops followed by crops pollinated by A. cerana indica. Significantly higher seed yield, 1000 seed weight, percentage of seed filling and number of seed per capitulum were recorded in these treatments. These findings indicate OP and HB increase 33 per cent more yield in sunflower.

Diversity of bumble bees and butterflies in Minnesota roadsides depends on floral diversity and abundance but not floral native status

Abstract Habitat loss is an important driver in the rapid decline of many insects. The restoration of roadside habitat has been touted as an opportunity to support communities of bumble bees and butterflies, two insect groups of conservation concern. However, it is unclear how current roadside restoration methods translate to pollinator abundance and diversity. Here, we ask how the plant communities of roadsides seeded with native and non‐native seed mixes affect bumble bee and butterfly communities 2–20 years after planting. We found that bumble bee and butterfly abundance and diversity were positively correlated with floral abundance and diversity. However, the pollinator community in plots planted with diverse native seed mixes did not differ from that found in plots seeded with species‐poor non‐native mixes, likely because many forbs in the native seed mixes had poor establishment, and all plots were readily colonised by species that were never planted. While plots with more native flowers did not necessarily support higher pollinator diversity, we did find several native plants that established well in roadsides and supported pollinators, including goldenrods (Solidago spp.), milkweeds (Asclepias spp.) and wild bergamot (Monarda fistulosa). Our data suggest that managing a more diverse and abundant floral community will benefit bumble bees and butterflies. Refining the composition of native seed mixes, adding more floral abundance to non‐native mixes and investing in management for native plant communities may increase the habitat value of roadsides for pollinator communities.

Effects of climate change on Lepidoptera pollen loads and their pollination services in space and time.

Shifts in flowering time among plant communities as a result of climate change, including extreme weather events, are a growing concern. These plant phenological changes may affect the quantity and quality of food sources for specialized insect pollinators. Plant-pollinator interactions are threatened by habitat alterations and biodiversity loss, and changes in these interactions may lead to declines in flower visitors and pollination services. Most prior research has focused on short-term plant-pollinator interactions, which do not accurately capture changes in pollination services. Here, we characterized long-term plant-pollinator interactions and identified potential risks to specialized butterfly species due to habitat loss, fragmented landscapes, and changes in plant assemblages. We used 21years of historical data from museum specimens to track the potential effects of direct and indirect changes in precipitation, temperature, monsoons, and wildfires on plant-pollinator mutualism in the Great Basin and Sierra Nevada. We found decreased pollen richness associated with butterflies within sites, as well as an increase in pollen grain abundance of drought-tolerant plants, particularly in the past 10years. Moreover, increased global temperatures and the intensity and frequency of precipitation and wildfires were negatively correlated with pollen diversity. Our findings have important implications for understanding plant-pollinator interactions and the pollination services affected by global warming.

Pollinating insects form different modules with Malvaceae crops in a global meta-network

ABSTRACT This study aims to build a global meta-network of interactions between Malvaceae crops (cocoa, cupuassu, cotton and okra) and their pollinators. The network structure was described by connectivity and modularity, and centrality metrics were used to analyze the role of species. A total of 217 pollinator species was recorded, distributed in four orders. The network has four modules, low connectance (C = 26%) and a high modularity (Q = 0.58). Apis mellifera was the only network connector species. Each crop is pollinated by a very specific group of species, indicating that productivity maintenance may be favored by the conservation of pollinators diversity.

Floral traits and their connection with Pollinators and Climate.

Floral characteristics vary significantly among plant species, and multiple underlying factors govern this diversity. Although it is widely known that spatial variation in pollinator groups can exert selection on floral traits, the relative contribution of pollinators and climate to the variation of floral traits across large geographic areas remains a little-studied area. Besides furthering our conceptual understanding of these processes, gaining insight into the topic is also of conservation relevance: understanding how climate may drive floral traits variation can serve to protect plant-pollinator interactions under global change conditions. We used Rhododendron as a model system and collected floral traits (corolla length, nectar volume and concentrations), floral visitors, and climatic data on 21 Rhododendron species across two continents (North America-Appalachians and Asia-Himalaya). Based on this we quantified the influence of climate and pollinators to floral traits using phylogeny-informed analyses. Our results indicate that there is substantial variation in pollinators and morphological traits across Rhododendron species and continents. We came across four pollinator groups: birds, bees, butterflies, and flies. Asian species were commonly visited by birds, bees, and flies, while bees and butterflies were the most common visitors of North American species. The visitor identity explained nectar trait variation, with flowers visited by birds presenting higher volumes of dilute nectar and those visited by insects producing concentrated nectar. Nectar concentration and corolla length exhibited a strong phylogenetic signal across the analysed set of species. We also found that nectar trait variation in the Himalaya could also be explained by climate, which presented significant interactions with pollinator identity. Our results indicate that both pollinators and climate contribute and interact to drive nectar trait variation, suggesting that both can affect pollination interactions and floral (and plant) evolution individually and interacting with each other.

Dynamics of Berry Characteristics, Biochemical Composition, and Physiological Responses Across Ripening Stages: Investigating the Impact of Pollinizer Varieties on Physiological Femaleness in Bozcaada Çavuşu (Vitis vinifera L. cv)

AbstractUnderstanding the dynamic changes in grape characteristics during ripening is crucial for enhancing grape quality, which, in turn, influences overall viticulture practices. This study aimed to investigate the temporal and cultivar-specific variations in grape characteristics, focusing on BAs, phenolic compounds, antioxidant enzymes, and organic acids. Our results revealed that Bozcaada Çavuşu*Kuntra and Kuntra grapes exhibited the most significant growth in size, weight, and maturity index at the final developmental stage (EL-38), while Vasilâki showed a nuanced maturation pattern with significant increases in berry width but not weight. Across all varieties, the highest maturity index and Total Soluble Solids percentages were observed at EL-38. The investigation of BAs revealed a significant decrease in Put levels from 2.62 at EL-32 to 2.04 mg L−1 at EL-38, contrasting with an increasing trend in Agm concentrations from 0.25 at EL-29 to 0.37 mg L−1 at EL-38. Bozcaada Çavuşu*Kuntra stood out with the highest Cad concentration at 2.96 mg L−1. The analysis of phenolic compounds highlighted a distinct temporal pattern for gallic acid, increasing from 1.60 at EL-29 to 3.77 g L−1 at EL-32 and maintaining stability at 3.74 g L−1 at EL-38. Bozcaada Çavuşu*Vasilâki consistently exhibited higher concentrations of phenolic compounds, such as epicatechin (5.69 g L−1) and tyrosol (7.00 g L−1). Antioxidant enzymes like catalase and superoxide dismutase in grape cultivars showed significant temporal variations, indicating a dynamic oxidative stress response during berry ripening. Catalase activity decreased from 14.04 to 11.20 EU/gr berry between EL-29 and EL-38. The multifaceted regulation of superoxide dismutase by sampling time and cultivar highlighted the complexity of antioxidant dynamics in grapevine physiology. In conclusion, this comprehensive study sheds light on the intricate interplay of temporal and cultivar-specific factors influencing grape characteristics, providing valuable insights for optimizing viticulture practices and enhancing overall grape quality.

Floral and pollinator functional diversity mediate network structure along an elevational gradient

AbstractElevational gradients in alpine ecosystems are well suited to study how plant and pollinator communities respond to climate change. In the Austrian Alps, we tested how the taxonomic and functional diversity of plants and their pollinators change with increasing elevation and how this affects plant–pollinator network structure. We measured the phenotypes of flowering plants and their pollinators and observed their interactions in 24 communities along an elevational gradient. To assess variation in floral and pollinator traits, we then quantified trait spaces (n-dimensional hypervolumes) occupied by flowers and pollinators in each community. To assess plant–pollinator network structure, we quantified the levels of complementary specialization (H2’), modularity and nestedness (weighted NODF) for each community. As elevation increased, most measures of diversity and network specialization either declined linearly or in an oscillating manner. Communities that exhibited higher pollinator functional diversity exhibited larger degrees of complementary specialization and modularity; and communities with greater floral and pollinator functional diversity and higher phylogenetic diversity were less nested. Altogether, the degree to which elevation, species diversity, functional diversity and network structure changed in conjunction suggests environmental effects on the functional and phylogenetic diversity of plants and pollinators and consequently network structure. Our results suggest that the effects of climate change on plant and pollinator community composition will impact plant–pollinator network structure and potentially pollination services at the community scale.

Modern pollen-plant diversity relationship in open landscapes of Tibetan Plateau

Past plant diversity dynamics can provide a historical perspective on biodiversity change and ecosystem dynamics as a guide to conservation management in the future. Pollen analysis is one of the most widely used approaches to reconstruct plant diversity change through time, but the representativeness of pollen diversity to plant diversity is not yet fully understood and especially in open landscapes. In this paper, we compare pollen assemblages from topsoil in the open landscapes of the Tibetan Plateau with the surrounding vegetation to investigate their compositional similarity and the correlations between their diversity (richness and evenness), and to evaluate the influence of climate variables, landscape characteristics, and human disturbance on the pollen diversity. The results show that pollen assemblages vary obviously in different vegetation types and they can represent their surrounding plant communities at low taxonomic levels. Pollen richness boarders a better match with plant richness than pollen evenness with plant evenness across the whole study area, but the correlation is weak (radj2 < 0.2, p < 0.001). Transforming plants into their pollen equivalents has little improvement for the correlations between pollen and plant richness/evenness. Pollen richness and evenness can capture well the trend in plant richness and evenness along the vegetation gradient, suggesting that they can be used as gamma (landscape scale) rather than alpha (local scale) diversity metrics in the study area. Mean annual precipitation (MAP), mean annual temperature (MAT), and patch richness (PatchS) are positively associated with pollen richness. MAP, PatchS, and human disturbance (HD) are significantly predictors for pollen evenness. These confirm that pollen richness and evenness can provide insights into past plant diversity dynamics and help evaluating the effects of climate and habitat changes and human disturbance on long timescales.

Untangling biodiversity interactions: A meta network on pollination in Earth's most diverse tropical savanna.

Pollination is vital for ecosystem functioning, especially in biodiversity-rich regions like the Brazilian Cerrado. Our research establishes a comprehensive meta network of pollinator-plant interactions within this biome. We quantified the importance of different pollinator groups, identifying keystone species. We examined potential biases in sampling effort and the spatial behavior of interactions within the heterogeneous Cerrado plant physiognomies. Our investigation uncovered 1499 interactions among 293 plant species and 386 visitor species, with legitimate pollination accounting for 42.4% of the interactions. The network exhibited modularity, driven by bees and insects, with vertebrates bridging diurnal and nocturnal modules. While a generalized pattern emerged, high specialization existed within modules due to habitat diversity. Bees, particularly Apis mellifera (exotic) and Trigona spinipes (native), played central roles as network hubs. Hummingbirds and bats, engaged in specialized interactions showing strong connectivity within and between modules. Interestingly, invertebrate-vertebrate modules were more prevalent than expected in the meta network. However, a bias was evident, primarily within specific biogeographical districts with fragmented landscapes and intrusion from other biomes. Variations in plant species and endemism rates influenced pollinator occurrence and the Cerrado network topology. Our study offers valuable insights into pollinator-plant interactions within the Cerrado, encompassing both invertebrates and vertebrates. The modeled network represents a significant step in understanding the structural complexity of pollination networks, integrating partial networks from diverse pollination systems within heterogeneous habitats. Nevertheless, a biogeographical bias could limit a comprehensive understanding of network functionality across the Cerrado.

Intensive pasture management alters the composition and structure of plant-pollinator interactions in Sibiu, Romania.

Land management change towards intensive grazing has been shown to alter plant and pollinator communities and the structure of plant-pollinator interactions in different ways across the world. Land-use intensification in Eastern Europe is shifting highly diverse, traditionally managed hay meadows towards intensive pastures, but few studies have examined how this influences plant-pollinator networks. We hypothesized that the effects of intensive grazing on networks will depend on how plant communities and their floral traits change. We investigated plant and pollinator diversity and composition and the structure of plant-pollinator interactions near Sibiu, Romania at sites that were traditionally managed as hay meadows or intensive pastures. We quantified the identity and abundance of flowering plants, and used transect walks to observe pollinator genera interacting with flowering plant species. We evaluated the effects of management on diversity, composition and several indices of network structure. Pollinator but not plant diversity declined in pastures and both plant and pollinator taxonomic composition shifted. Functional diversity and composition remained unchanged, with rather specialized flowers having been found to dominate in both hay meadows and pastures. Apis mellifera was found to be the most abundant pollinator. Its foraging preferences played a crucial role in shaping plant-pollinator network structure. Apis mellifera thus preferred the highly abundant Dorycnium herbaceum in hay meadows, leading to hay meadows networks with lower Shannon diversity and interaction evenness. In pastures, however, it preferred less abundant and more generalized flower resources. With pollinators being overall less abundant and more generalized in pastures, we found that niche overlap between plants was higher. With both hay meadows and pastures being dominated by plant species with similar floral traits, shifts in pollinator preferences seem to have driven the observed changes in plant-pollinator interaction networks. We thus conclude that the effects of grazing on pollinators and their interactions are likely to depend on the traits of plant species present in different management types as well as on the effects of grazing on plant community composition. We thereby highlight the need for better understanding how floral abundance shapes pollinator visitation rates and how floral traits may influence this relationship.

Route of exposure to veterinary products in bees: Unraveling pasture's impact on avermectin exposure and tolerance in stingless bees.

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

Unveiling of climate change-driven decline of suitable habitat for Himalayan bumblebees

Insect pollinators, especially bumblebees are rapidly declining from their natural habitat in the mountain and temperate regions of the world due to climate change and other anthropogenic activities. We still lack reliable information about the current and future habitat conditions of bumblebees in the Himalaya. In this study, we used the maximum entropy algorithm for SDM to look at current and future (in 2050 and 2070) suitable habitats for bumblebees in the Himalaya. We found that the habitat conditions in the Himalayan mountain range do not have a very promising future as suitable habitat for most species will decrease over the next 50 years. By 2050, less than 10% of the Himalayan area will remain a suitable habitat for about 72% of species, and by 2070 this number will be raised to 75%. During this time period, the existing suitable habitat of bumblebees will be declined but some species will find new suitable habitat which clearly indicates possibility of habitat range shift by Himalayan bumblebees. Overall, about 15% of the Himalayan region is currently highly suitable for bumblebees, which should be considered as priority areas for the conservation of these pollinators. Since suitable habitats for bumblebees lie between several countries, nations that share international borders in the Himalayan region should have international agreements for comprehensive pollinator diversity conservation to protect these indispensable ecosystem service providers.

Pollen indices of Cedrus atlantica Manetti populations vary with geographical localities in the Moroccan Atlas Mountains

North Africa’s forests of Cedrus atlantica Manetti have declined drastically, by more than 58% in the last 130 years, and many stands are likely to disappear entirely in the coming decades. This study on the interactions between C. atlantica pollen characters (production, germination, and pollen tube length) and locality characters in Morocco, using seventy individuals from seven geographically distant populations, showed that pollen indices varied according to station. Pollen production was high in the populations of the Moudemam-1 and Seheb stations, intermediate in the Ait Oufella and Ait Ayach stations, and low in the Zerrouka, Ras Elma and Moudemam-2 stations. Pollen germination was very low for the populations in the Seheb and Moudemam-1 stations but high in the other stations. On the other hand, the longest pollen tubes were recorded in the Moudemam-1 population, while those in the other stations were shorter. These results show an inverse variation between the pollen indices characterizing the populations of the stations studied. The shortest pollen tube length classes [0-100] to [300-400] accounted for 85.98% of all classes and were assessed for the Zerrouka, Ait Oufella and Ait Ayach stations. The other classes were more represented or exclusive to the population of the Moudemam-1 station. These results could have implications not only for assessing pollen variations according to geographical localities but also for optimizing fertilization in cedar forests by selecting the best clones for this species.

An Account of Diversity of Pollinators from Bangladesh

This study explores the diversity, relative abundance, evenness, and richness of pollinators in the Rajshahi University Campus, in Bangladesh. A total of 625 individuals belonging to both invertebrates and vertebrates were recorded. Among the invertebrates, 44 insect species in five orders such as Hymenoptera, Diptera, Hemiptera, Coleoptera, and Lepidoptera were collected. The results revealed that the Lepidoptera and Hymenoptera were more abundant. Around 17 vertebrates in four orders, including Aves and Mammalia were also recorded. The diversity indices were: H'=3.82, with the Evenness (E=0.93), and Margalef’s Richness Index (d=9.32). Also 59 pollinator-visiting plants were enlisted.

Differential response of plant and insect pollinator communities to fragmentation in coastal dune slacks

Abstract Habitat destruction and fragmentation are one of the main drivers of pollinator decline and biodiversity loss in general. However, the exact effects of habitat fragmentation on pollinator communities are still poorly understood, and it remains unclear which patch characteristics are most important in driving pollinator diversity and community composition. In this study, we inventoried plant and insect diversity in a total of 19 fragmented dune slacks in Belgium. Specifically, we assessed the effects of dune slack area and connectivity on plant and pollinator diversity and community composition. Additionally, we investigated to what extent plant diversity had an impact on insect pollinator communities. The results indicated that species richness of both plants and insects was significantly related to patch area, whereas patch connectivity only had a significant effect on plant diversity. Nestedness analyses showed that plant communities of small dune slacks were a subset of the communities of large patches, but no such patterns were found for insect communities. Turnover in pollinator communities was high and significantly related to the distance separating dune slacks. Overall, our results highlight the importance of large patches for sustaining both plant and pollinator communities. Additionally, enhancing connectivity has the potential to promote plant diversity and consequently benefit pollinator species.

High pesticide exposure and risk to bees in pollinator plantings adjacent to conventionally managed blueberry fields

Wildflower plantings adjacent to agricultural fields provide diverse floral resources and nesting sites for wild bees. However, their proximity to pest control activities in the crop may result in pesticide exposure if pesticides drift into pollinator plantings. To quantify pesticide residues in pollinator plantings, we sampled flowers and soil from pollinator plantings and compared them to samples from unenhanced field margins and crop row middles. At conventionally managed farms, flowers from pollinator plantings had similar exposure profiles to those from unenhanced field margins or crop row middles, with multiple pesticides and high and similar risk quotient (RQ) values (with pollinator planting RQ: 3.9; without pollinator planting RQ: 4.0). Whereas samples from unsprayed sites had significantly lower risk (RQ: 0.005). Soil samples had overall low risk to bees. Additionally, we placed bumble bee colonies (Bombus impatiens) in field margins of crop fields with and without pollinator plantings and measured residues in bee-collected pollen. Pesticide exposure was similar in pollen from sites with or without pollinator plantings, and risk was generally high (with pollinator planting RQ: 0.5; without pollinator planting RQ: 1.1) and not significant between the two field types. Risk was lower at sites where there was no pesticide activity (RQ: 0.3), but again there was no significant difference between management types. The insecticide phosmet, which is used on blueberry farms for control of Drosophila suzukii, accounted for the majority of elevated risk. Additionally, analysis of pollen collected by bumble bees found no significant difference in floral species richness between sites with or without pollinator plantings. Our results suggest that pollinator plantings do not reduce pesticide risk and do not increase pollen diversity collected by B. impatiens, further highlighting the need to reduce exposure through enhanced IPM adoption, drift mitigation, and removal of attractive flowering weeds prior to insecticide applications.

Species diversity, behavior and visit rates to melon flowers (Cucumis melo l.) as a function of time and seasonality in a semi-arid climate region in Brazil

In this research we evaluated the phenology of melon flowering (Cucumis melo L.) and the diversity of floral visitors in geographical conditions of semi-arid climate in Northeast Brazil, during the wet and dry seasons. The floral phenology of the melon was evaluated by recording the number of flowers produced/plant/day from 30 plants, the insects that visited the flowers were recorded following three methods: visual counts, sweep collection and counting and identification, we observe and count the number of visits to flowers from 30 plants (n = 30) during the first 45 minutes of each hour. This study reports the diversity of melon pollinators in geographical conditions located in a semi-arid climate region, with specific seasonal fluctuations, which explains the behavior pattern found at work. The order Hymenoptera predominated among floral visitors, especially Apis melífera and Trigona spinipes. The flowering cycle was influenced by seasonality, with a longer duration in the dry season, the flowering and visiting peaks were higher during the hottest hours of the day, regardless of the season. There was a preference for visitation in the morning hours, with a peak at 10 a.m. and a gradual decrease in the presence of insects in the late afternoon.