Butterfly Species Richness Research Articles

Sown wildflower meadows: Can they replace natural meadows in urban spaces for bees, butterflies and hoverflies?

Abstract The decline in pollinator populations is partly due to human practices that have contributed to the loss of wild and flower‐rich habitats. In cities, especially city centres, urban green spaces, which are usually small, are often sown with wildflower meadows. The study compared the number and species richness of three main groups of pollinating insects (wild bees, butterflies and hoverflies) for two types of meadows in Warsaw: sown wildflower meadows and the natural meadows. The research results showed that there was no difference in the composition of insect‐pollinated plants between the meadow types. There was also no difference between the meadow types concerning the species richness of butterflies, bees and hoverflies. However, it was confirmed that the number of butterflies was twice as high in natural meadows than it was in sown floral meadows, while in the case of wild bees and hoverflies, no such differences were found. The study confirmed that areas sown with wildflowers, usually of small area, concentrate pollinating insects and have a similar value for pollinators as larger areas of natural meadow. Sown wildflower meadows, if properly cared for, can ensure the richness of melliferous plant species and thus positively affect the diversity and number of pollinators. Sown meadows can compensate insects for the absence of large, natural meadows, especially in the fragmented spaces in cities.

Complex stands in forested tropical landscapes harbor more endemic biodiversity and ecosystem functions

Transformation of forests into agricultural lands threatens biodiversity and ecosystem functions globally. In the biodiversity hotspot Madagascar, key ecosystem functions along with highly endemic flora and fauna are under threat. Comprehensive studies identifying determinants of biodiversity and ecosystem function losses are lacking, with no studies accounting for endemic species richness across multiple taxa. We assess how plot-scale stand structural attributes (basal area, leaf area index, diameter diversity, and tree species richness) and landscape-scale forest cover influence biodiversity (species richness of butterflies, ants, birds, reptiles, amphibians, herbaceous plants, and multidiversity) and ecosystem functions (soil organic carbon, predation rate, acoustic diversity, and multifunctionality) in the tropical mosaic landscape of northeastern Madagascar. Complexly structured stands with a larger basal area and/or a higher tree species richness promoted greater endemic multidiversity (R² = 0.70), soil organic carbon, and acoustic diversity. However, our models did not indicate significant explanatory variables for multidiversity (R² = 0.25) and multifunctionality (R² = 0.43). Landscape-scale forest cover significantly favored endemic bird species richness. Our findings highlight that a simplified stand structure, resulting from land-use change, substantially reduces endemic biodiversity and ecosystem functions in this historically forested region. Conservation actions should aim at maintaining complex stand structure in forests and agroforests, while restoration interventions should focus on re-building such structures.

Development of insects in newly established grassland over six years: Increased conservation benefits through diverse plant communities

Agri-environmental schemes seek to mitigate the loss of biodiversity by subsidizing the restoration of grassland in Europe. However, little is known about the colonization of newly established grasslands by insects, especially over periods exceeding 1–2 years. Therefore, we investigated the development of species richness, abundance and species assemblages of wild bees, syrphids, butterflies, orthopterans and true bugs in two types of newly established grassland strips in an agricultural landscape in Austria over a six-year time span. We compared currently subsidized plant-species poor grassland strips (SG; Ecological Focus Areas) with newly established grassland strips (NG) that were created with a diverse, regionally adapted seed mixture, to find out whether diverse seed mixtures can ensure lasting improvements in the insect species richness of grassland strips over a 6-year period. We used permanent seminatural grasslands (old grassland OG) as reference habitat. From the first year after establishment, we found no differences in syrphid assemblages between OG and NG. In contrast, true bug assemblages in NG differed significantly from those in OG still five years after establishment. Wild bee, butterfly and orthopteran species composition differences between grassland strips (NG, SG) and permanent grasslands (OG) were decreasing over time. However, we found no evidence of a successional change in insect species assemblages in NG and SG. NG promoted a significantly higher wild bee richness and equivalent syrphid, butterfly, orthoptera and true bug richness compared with OG. Over the study period, NG showed sustained insect diversity, outperforming plant species-poor SG in promoting wild bee, syrphid and true bug richness. Therefore, we suggest that diverse and regional seed mixtures could enhance the effectiveness of grassland restoration for insect conservation and could make re-sowing within the first 6 years after establishment unnecessary.

Traffic intensity and vegetation management affect flower‐visiting insects and their response to resources in road verges

Abstract Road verges can support high densities of flowers and could therefore provide new opportunities for the conservation of flower‐visiting insects. One way of optimizing road verges for vascular plant diversity is to adjust mowing regimes, but to date it is unclear how this affects flower‐visiting insects. Furthermore, for mobile organisms like wild bees and butterflies, there is a risk that the benefit of increased habitat quality in road verges is limited by the proximity to traffic, but this is poorly studied. In a crossed study design, we separated mowing time and frequency (early summer and autumn, or only late summer) from road verge habitat classification (valuable for biodiversity according to transport authority, or regular). We did so along a gradient of traffic intensity, to investigate if a mowing regime designed to enhance plant diversity can also benefit wild bees and butterflies, and if traffic limits the conservation potential of road verges. Road verges that were mown only in late summer had higher flower densities, and there was a positive relationship between flower density and wild bee abundance and species richness. Butterfly abundance and species richness only benefitted from a late summer mowing in valuable but not in regular road verges. Traffic intensity had a substantial negative impact on abundance and species richness of wild bees and butterflies. Higher traffic intensities limited the positive relationship between plant and butterfly species richness that we observed at lower traffic intensities. Increasing width of the road verges buffered negative effects of the traffic on wild bee as well as butterfly abundances, and on wild bee species richness. Synthesis and applications. Road verges can play a valuable role for the conservation of wild bees and butterflies, but there is a need to consider both traffic intensity and resource availability when implementing management strategies. To support wild bee and butterfly diversity, we recommend actions to enhance plant species richness and flower resource availability, and to focus these conservation efforts on roads with low traffic intensity, or on wide road verges.

Maintaining habitat diversity at small scales benefits wild bees and pollination services in mountain apple orchards

Abstract Landscape context influences wild bee abundance and diversity, alongside pollination‐related services. Growing evidence supports the positive effects of landscape heterogeneity on bee diversity and fruit production for pollination‐dependent crops in flatlands. However, little remains known about these relationships in mountainous environments where the landscape matrix surrounding crops is often more complex than in lowlands. We conducted our study in apple orchards in South Tyrol, an Alpine region in Italy, using pan‐traps, direct observations of visitation frequency and a pollinator exclusion experiment. We investigated the scale‐dependent effects of landscape heterogeneity and other parameters on wild bee assemblages and the related pollination service they provide at five spatial scales (radius 100–2000 m). We found that landscape heterogeneity positively affected the abundance and richness of wild bees, with the strongest effect at 500 m. We calculated a multidiversity index, reflecting the land‐use intensity based on the species richness of vascular plants, grasshoppers, butterflies, birds and bats. We identified a positive relationship between this multidiversity index and wild bee richness. Additionally, we found that visitation rate of wild bees was negatively affected by crop cover and that abundance of honeybees did not influence wild bee visitation rate or reproductive success. Finally, reproductive success was positively related to semi‐natural habitat cover. Landscape heterogeneity should be maintained in apple orchards to continue to reap the benefits of vital pollination‐related services. Diversification strategies should be implemented to promote habitat diversity at small scales, even in regions with more than 80% of (semi‐)natural habitats.

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.

Wildlife-friendly garden practices increase butterfly abundance and species richness in urban and arable landscapes

Insect declines are being reported worldwide and private, residential gardens could provide refugia for these species under increasing land use change. Interest in wildlife-friendly gardening has increased, but many management recommendations lack a scientific evidence-base. We used a large citizen science scheme, the Garden Butterfly Survey (GBS), with data from over 600 gardens across Great Britain (2016–2021) to determine how the surrounding landscape influences the abundance and species richness of butterflies in gardens and whether wildlife-friendly gardening practices, such as having long grass and providing nectar plants, benefit butterflies. First, we show that GBS provides reliable estimates of species abundances by comparing with results from standardised, long-term monitoring data. Garden size and surrounding land use had significant effects on butterfly abundance and richness in gardens, including positive relationships with garden size, woodland and arable farmland and negative relationships with urbanisation. Both the presence and area of long grass in gardens were positively related to higher butterfly richness and abundance, with the latter being driven by butterflies that use grasses as larval host plants. These effects differed depending on the surrounding landscape, such that long grass resulted in higher garden butterfly abundance in landscapes dominated by arable farming, and higher abundance and richness in highly urbanised areas. The presence of flowering ivy (Hedera spp.) in gardens resulted in higher abundance of Celastrina argiolus holly blue which uses ivy as a larval host, and of Vanessa atalanta red admiral and Polygonia c-album comma, which favour it as a nectar source. Our work provides evidence that undertaking simple wildlife-friendly garden practices can be beneficial for attracting butterflies, particularly in heavily modified areas. With over 728,000 ha of gardens in Great Britain, the cumulative effect of leaving areas of lawn uncut and providing nectar and larval host plants could be key for helping biodiversity.

How do management decisions impact butterfly assemblages in smallholding oil palm plantations in Peninsular Malaysia?

Abstract In the world's leading palm oil‐producing countries (Indonesia and Malaysia), smallholders make up about 40 per cent of total oil palm plantation area. Management in smallholdings can be highly variable, ranging from intensive monoculture to polyculture systems, especially in the earlier years of cultivation when open canopies allow a variety of understorey crop types to be grown alongside oil palm. Currently, many plantations in the region are mature and due to be replanted, which is likely to have substantial impacts on the ecosystems within them, but studies investigating the impacts of alternative post‐replanting management strategies in smallholder plantations are lacking. We investigated the impacts of replanting and choice of crop management following replanting (growing oil palm as a monoculture or polyculture) on habitat structure and complexity, and on the abundance, richness and composition of butterfly assemblages in smallholding oil palm plantations in Banting, Selangor, Malaysia. We also assessed the direct effects of habitat structure and complexity on butterfly assemblages. Butterflies are likely to be a valuable indicator group for monitoring the impacts of management practices on biodiversity as butterfly species also show a range of sensitivities to habitat disturbance, with some being vulnerable to change, but others being common in plantations. They are also a functionally important group that pollinate wild plants, are prey for larger species and are common in tropical systems. Across 27 plantations, we recorded 1227 butterflies from 5 families, 46 genera and 56 species. Habitat structure and complexity differed between management decisions (mature monoculture, immature monoculture, immature polyculture), although many environmental parameters overlapped. We found no significant differences in species richness, density and assemblage composition of butterflies between management decisions. However, changes in local environmental conditions, such as an increase in the coverage of understorey vegetation, increased the abundance of butterflies. Synthesis and applications. Our findings suggest that replanting oil palm and choice of mono or polyculture have relatively few effects on butterflies, but management for specific features in plantations could benefit butterfly assemblages.

Species richness and dispersion patterns of Lepidoptera (Rhopalocera) in the Nuraksa Forest Park, Lombok, Indonesia

Abstract. Ilhamdi ML, Idrus AA, Santoso D, Hadiprayitno G, Syazali M, Hariadi I. 2023. Species richness and dispersion patterns of Lepidoptera (Rhopalocera) in the Nuraksa Forest Park, Lombok, Indonesia. Biodiversitas 25: 62-70. Butterflies play an important role in maintaining the balance of ecosystems and pollinators. This study aims to analyze the species richness and dispersion patterns of butterflies from the Rhopalocera suborder in this area. The field survey was carried out from January to July 2023. The sampling site was divided into six areas. Specimens that were successfully collected using a hand net were identified at the Biological Laboratory of Mataram University. During this survey, 1576 specimens of Rhopalocera were recorded. This number consists of 47 species. Several species, such as Junonia atlites Linnaeus, 1763, Junonia almana Linnaeus, 1758, Danaus genutia Cramer, 1779, Hypolimnas misippus Linnaeus, 1764, and Amathusia phidippus Linnaeus, 1763 were found to be new records in the Nuraksa Forest Park area. The habitat types with the highest number of species are the utilization block and the traditional block, with 47 species. The habitat type with the lowest number of species is a special block with only 15 species. However, the highest species richness was found in the protection block, with an R-value of 8.09. The most dominant species is Leptosia nina Fabricius, 1793, and the least dominant is A. phidippus. Each species depicted a varying distribution in the six habitat types. According to the analysis results, it was found that the dispersion pattern of all Rhopalocera species is clustered. The research results themselves contribute to conservation and ecotourism efforts.

Butterfly loss in urban landscapes and nature reserves

ContextUrbanization and landscape homogenization are main drivers causing biodiversity loss across the globe. The transformation of natural and semi-natural habitats into agro-environments and settlement areas causes the reduction of species diversity, and thus faunal homogenization. ObjectiveIn this study, we analyse changes in land-cover and habitat configuration and test for changes in species richness and community composition of butterflies in an urban area and a nature reserve. MethodWe analysed historical and recent aerial and satellite pictures, and studied the butterfly fauna for two areas in northern Austria, the urban area around Salzburg city and the nature reserve Bluntautal in close geographic proximity. For these analyses we consider the period 1946–2018. ResultsThe proportion of settlement area and forest increased in average by about 5%. Size of field copses increased and small-scale connectivity and thus landscape complexity decreased in both areas. In the same time span, we found a decrease in butterfly species richness for both areas, and in the nature reserve Bluntautal particularly for the past two decades by 50%. The species community composition changed significantly, with severe losses of specialist and xerothermophilic species which rely on open and extensively used ecosystems. ConclusionsThe findings underpin that the reduction of landscape complexity and the intensification of land-use including urbanization drives the loss of diversity of butterflies and changes in species composition, today dominated by some few generalist species. This trend is particularly observable for the nature reserve Bluntautal, where a large proportion of species diversity has disappeared in recent years despite nature conservation. This case underlines habitat management in nature reserves is needed to hold a high level of habitat quality and to preserve the entire species diversity.

DNA metabarcoding and morphological identification reveal similar richness, taxonomic composition and body size patterns among flying insect communities

Abstract Tracking insect biodiversity trends and predicting future trajectories is limited by a lack of monitoring data across large spatiotemporal scales. DNA metabarcoding is a time‐ and cost‐efficient method to obtain these data, but has several potential limitations in comparison to traditional morphological approaches. For example, metabarcoding may miss low‐abundance or smaller bodied individuals and is limited to presence/absence information, which may bias estimates of biodiversity and community composition. However, few comparisons of metabarcoding and morphology‐based identification have been made using insects, the by far most diverse animal taxonomic group. Here, we compared terrestrial insect communities identified via morphology versus metabarcoding across four different habitats and three seasons (late spring, mid‐summer and early autumn) during 2019. We compared identified species and community richness, composition and body size, with a focus on key taxonomic groups of bees, true bugs, butterflies and hoverflies. We identified 252 total species, with 54.8% identified by both methods, whereas 21.4% and 19.8% were solely detected with metabarcoding or morphology, respectively. Overall, total community richness, taxonomic composition and community body size were similar between methods. Metabarcoding detection successes declined in low‐abundance and smaller taxa, particularly bees, hoverflies and true bugs; however, species richness of hoverflies and butterflies tended to be higher compared with morphological identification. Our results show that metabarcoding can provide an accurate overview of insect community differences that are comparable to those determined via morphological identification. We recommend that insect monitoring programmes consider incorporating metabarcoding, although future research is needed to overcome some remaining limitations.

Insecticides, more than herbicides, land use, and climate, are associated with declines in butterfly species richness and abundance in the American Midwest.

Mounting evidence shows overall insect abundances are in decline globally. Habitat loss, climate change, and pesticides have all been implicated, but their relative effects have never been evaluated in a comprehensive large-scale study. We harmonized 17 years of land use, climate, multiple classes of pesticides, and butterfly survey data across 81 counties in five states in the US Midwest. We find community-wide declines in total butterfly abundance and species richness to be most strongly associated with insecticides in general, and for butterfly species richness the use of neonicotinoid-treated seeds in particular. This included the abundance of the migratory monarch (Danaus plexippus), whose decline is the focus of intensive debate and public concern. Insect declines cannot be understood without comprehensive data on all putative drivers, and the 2015 cessation of neonicotinoid data releases in the US will impede future research.

KEANEKARAGAMAN JENIS KUPU-KUPU (PAPILIONOIDEA) DI GUNUNG API PURBA NGLANGGERAN [The Diversity of Butterflies (Papilionoidea) at Nglanggeran Ancient Volcano

The presence of butterflies can be found in several types of habitats and can be used as an indicator of environmental conditions. Geologically, the Nglanggeran Ancient Volcano is unique and has high scientific value. It is necessary to update the butterfly diversity data to determine the diversity of butterflies at Nglanggeran Ancient Volcano. The purpose of this study was to determine the diversity, richness, evenness, and dominance of butterfly species at Nglanggeran Ancient Volcano. The exploration method was carried out to obtain data for three repetitions. There were 51 butterfly species with a total of 584 individuals, consisting of Nymphalidae (54.55%), Papilionidae (21.82%), Pieridae (20.00%) and Lycaenidae (3.64%). The index value of butterfly species diversity at Nglanggeran Ancient Volcano (2.97) was medium. The species evenness index (0.83) indicated that the species was relatively stable and evenly distributed. The richness of butterfly species was high, i.e. 6.70, suggesting that the current habitat was suitable for the life of the butterflies. The dominance index value was low, i.e. 0.12, indicating that there was no domination of certain species. The abundant species were Eurema sp. (23.12%), Ideopsis juventa (7.02%), and Catopsilia pomona (6.85%).

Diversity of Butterflies associated with Brassicaceae crops in Basra, Iraq

The study aimed to investigate the seasonal presence and characterization of the group of butterflies (abundance, richness and biodiversity) in the agroecosystem of Brassicaceae plants in the Basra province. Two different ecosystem sites (Karmat Ali at the sedimentary habitat and Al-Zubair region at the desert habitat) were sampled during the growing season of 2020/2021. There are 823 and 507 individuals at the Karmat Ali and Al-Zubair sites, respectively; the specimens consist of 9 butterflies belonging to four families. The most abundant family was Nymphalidae (60%), followed by Lycainidae (28%) and Pieridae (9%), while Hesperiidae recorded the lowest relative abundance of 3%. The highest butterfly population was recorded for Vanessa Carudi, while Pieris rapae had the lowest density. The results showed differences in abundance, species richness, and Diversity of butterflies at the sites. The highest values of Diversity and richness were at Karmat Ali, compared to the Al-Zubair region. The study of butterflies' abundance and biodiversity indices indicated that environmental factors and the polyculture plantations support the butterfly population in agricultural habitats. Keywords: Basra; Biodiversity; Brassicaceae; Butterflies; Shannon index; Richness.

Diversity, Seasonal Dynamics and Host Plants of Butterflies in Forest Research Centre, Siddipet, Telangana, India

Aim: This study aims at bringing out butterfly diversity through species richness, seasonal distribution and suitable host plant preferences of identified butterflies in Forest Research Centre, Siddipet, Telangana, India.
 Study Design: Line Transect Method is followed.
 Place and Duration of the Study: The study was conducted in Forest Research Centre (FRC), Siddipet, Telangana, India during 2021-2022.
 Methodology: Five line transects are laid across the research centre which are surveyed both in morning and afternoon at 9-11AM and 4-6PM respectively across the season viz., rainy, winter and summer seasons. Species identification was done based on the visual and photographical observations.
 Results: The study revealed a butterfly species richness of 53, spanning 39 genera and distributed across five families. These families included Nymphalidae (23 species), Pieridae (12 species), Lycaenidae (10 species), Papilionoidae (6 species), and Hesperiidae (2 species). When it came to host plant preferences, the butterflies showed a preference for families such as Fabaceae (23%), Malvaceae (16%), Capparaceae (12%), Acanthaceae (11%), and Poaceae (8%). Additionally, several other families, including Apocynaceae, Aristolochiaceae, Rhamnaceae, and Rutaceae, were found to host a few butterfly species. Regarding seasonal distribution, the study noted that butterfly species were more abundant during the winter season, followed by the rainy season, with the summer season exhibiting a significant difference in distribution and occurrence compared to the other two seasons.
 Conclusion: From the study, it can be concluded that FRC reported a diverse range of butterflies distributed across all the seasons making it potential site for preservation and conservation of butterflies and its host species.

Intensity of grassland management and landscape heterogeneity determine species richness of insects in fragmented hay meadows

Traditionally managed grasslands rank among the most species-rich ecosystems. However, in agricultural landscapes of Western and Central Europe, their extent has severely decreased. The remaining patches are mostly fragmented and suffer from habitat deterioration. Here, we studied the effects of environmental conditions on species richness of butterflies and grasshoppers in highly fragmented hay meadows. Our study revealed that environmental parameters at the habitat and landscape level influenced species richness of butterflies and grasshoppers in low-intensity hay meadows. In the univariable models, two groups of parameters consistently affected the number of all and threatened species: at the habitat level, species richness was fostered by structural richness, which was indicative of the overall management intensity of the grassland patches. At the landscape level, a higher number of mowing events in the landscape surrounding the hay meadows had a negative effect and higher elevations exhibiting a cooler and wetter climate had a positive effect on species richness. The former reflected the overall intensity of grassland management in the landscape and the later, together with further predictors (cover of forest, habitat connectivity, slope), the landscape heterogeneity. Consequently, the intensity of grassland management at the habitat and landscape level as well as the landscape heterogeneity, which was also related to land-use intensity, determined species richness of butterflies and grasshoppers. Based on these findings, there is an urgent need to enlarge the proportion of grasslands with low land-use intensity in the wider countryside. Additionally, conservation measures should aim at increasing landscape heterogeneity and habitat connectivity.

Landscape-level determinants of butterfly species richness in northern Europe: A country-wide survey reveals the paramount importance of forest land

Human-induced changes in habitat amount and quality constitute the key driver behind negative trends in global biodiversity. Conservation actions must be based on solid knowledge of the factors affecting species richness in the remaining habitat fragments. Besides local characteristics, it is critical to consider a broader spatial context when evaluating habitat quality. Here we present an analysis of landscape-level determinants of butterfly species richness based on a country-wide survey in Estonia, representing the northern European forest zone. This study compares favourably to previous research in its scope (over 1200 systematically selected sites), and provides a relatively ‘natural’ reference point for the analyses based on areas with higher human population density. The number of butterfly species locally recorded was sought to be explained by variables describing the surroundings of the study sites at four spatial scales. The proportion of forest land was by far the strongest factor (positively) affecting the number of butterfly species recorded, followed by soil alkalinity. Notably, the effects of forest land area at the smallest (in a radius of 250 m) and largest (2000 m) spatial scales were partly independent of each other. The former likely reflects immediate habitat quality while the latter should be related to the colonisation-extinction balance in the metapopulation context. The correlates of anthropogenic pressure (e.g., urbanization, roads, agriculture) had little effect. The results highlight the key role of designing responsible forestry practices in the regional context of nature conservation.

Land-use pattern and landscape structure impact butterfly diversity and abundance in organic agroecosystems

ContextAgricultural intensification and land-use patterns impact biodiversity and reduce ecosystem functions. Organic farming is often seen as a more biodiversity friendly way of farming. However, not all organic farming is equally supportive for biodiversity, structural diversity of the farms has a great impact and the often high intertwinement of organic and conventional farmland causes spill-over problems.ObjectiveOn organic farmland in central Italy, we analysed butterfly diversity and community structures in different land-use categories across a heterogeneous landscape. We aim to analyse the impact of the different land-use structures such as hedges and forest edges on this farmland, as well as the influence of adjoining conventionally farmed areas.MethodsWe studied butterflies on organic farmland including olive and hazelnut plantations, as well as meadows and fallow land, surrounded by hedges and forests. Hereby we considered the effects of land-use on the studied site and the adjoining land, e.g., semi-natural habitats (as hedges or forest edges), organic or conventional farmland. We counted butterflies along line transects and recorded habitat parameters for each transect. All encountered butterflies were classified according their ecological demands, behaviour, and life-history.ResultsWe found highest mean butterfly species richness in fallow land and lowest in hazelnut plantations. Species community structures differed hardly between plantations and meadows, but considerably compared to fallow land. Butterfly abundances are reduced for olive plantations adjacent to agricultural fields treated with pesticides, compared to such surrounded by organic fields. Habitat para-meters such as the number of flowering plant species and shade impact butterfly diversity and abundance. Forest edges producing considerable shadow to the transects had a significantly negative effect on diversity and abundance, while the influence of hedges was positive.ConclusionsBased on our findings, we conclude that also organic farmland has different degrees of biodiversity depending on a variety of land-use pattern. In particular, habitat heterogeneity and a high diversity of flowers positively influence butterfly diversity. The intensive mixing of organic and conventional agriculture must be seen critical for conservation as negative effects might spill over to organic fields, but might be compensable by landscape structures like hedges.

Butterflies are not a robust bioindicator for assessing pollinator communities, but floral resources offer a promising way forward

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.

Bumblebees and butterflies in green structure elements in Malmö, Sweden

Within the BiodiverCity project in Malmö (Sweden), green structure elements were implemented aiming to support biodiversity and enhancing amenity in denser parts of the city. In this study, bumblebee and butterfly abundances and species richness were studied in 20 green structure elements in three areas in Malmö. The investigated green structure elements consisted of objects established within the BiodiverCity project and other green structure elements in their surroundings (e.g. road verges, lawns and flowerbeds). Observed bumblebee and butterfly abundances and species richness was generally low. In total, 528 bumblebees of eight species were recorded, with 97% of all bumblebees belonging to two species, Bombus lapidarius and B. terrestris/lucorum. A total of 154 butterflies from 10 species were detected, most commonly Pieris species. There were no significant differences in mean individual or species numbers (bumblebees and butterflies) between green structure elements designed to support biodiversity and conventional ones. Bumblebee species richness and abundance were positively correlated with mean cover of flowering vegetation and mean number of flowering plant species. Butterfly species richness and abundance were positively correlated with mean number of flowering plant species and size of the green structure. Observations of flower visits showed that the two groups of insects had different preferences. The results of this study show that enhancing bumblebee and butterfly diversity and abundances in densely built city areas can be challenging. To support bumblebees and butterflies more successfully, the habitat requirements of these insect groups need to be better considered from the beginning in the design of green structure elements.