Agriculture is a major driver of insect pollinator decline, yet organic farming is generally associated with higher pollinator diversity than conventional management. Apple, a pollinator-dependent crop of major economic importance, relies heavily on wild bees, which are often more effective pollinators than honeybees. We assessed foraging activity and behavior of insect flower visitors in apple orchards under organic and conventional management in central Chile, a global bee biodiversity hotspot, at different locations within crop plots, using video monitoring. Surprisingly, visit rates of wild and managed pollinators did not differ between conventional and organic orchards, but were higher at crop edges for wild insects and lower for honeybees, as expected. Honeybees accounted for 92
Apples are dependent upon pollinators for the transfer of pollen between cultivars to ensure high quality fruit production. Agricultural intensification has reduced the availability of stable floral resources for wild bees, leading to widespread declines of important pollinators of apples. Managed honeybees are commonly used to supplement pollination services in apple orchards, but honeybees are less efficient pollinators compared to wild bees. We investigated whether increased flower abundance in the understory vegetation of apple orchards can increase pollinator activity to apple flowers. We compared bee visitation in five orchards in Eastern Norway: three unmowed orchards, and two mowed orchards. In unmowed orchards, dandelions (Taraxacum spp.) dominated the understory vegetation. Bee observations were conducted on the understory vegetation and apple trees, via manual observations and time-lapse cameras. Wild bees preferentially visited apple flowers over dandelions, while honeybees did not differ in their visits to apple flowers and dandelion flowers. We also found that the abundance of dandelion flowers in the understory increased visits by wild bees to apple flowers. Taken together, this suggests that within orchard floral resources do not compete for pollinators but instead increase apple visitation and improve pollination success. Our results highlight the importance of managing apple orchards for wild bee populations and the potential short-term benefits of understory floral resources on apple production. Our results show that understory vegetation should be left unmowed to increase pollination of apple flowers and provide pollinators with alternate floral resources before, during, and after apple flowering.
Ambrosia and bark beetles have been widely studied in both tropical and temperate forest regions. However, studies on their diversity across different forest types and their seasonal variation in the warm-temperate forest of Japan remains limited. We investigated the diversity and seasonal variation of ambrosia and bark beetles across two forest types in southern Japan. We collected ambrosia and bark beetles using flight interception traps set in Japanese cedar forests and secondary broadleaf forests across four seasons in Kagoshima Prefecture, Japan. We collected a total of 2,728 specimens representing 41 species, comprising 34 ambrosia beetle species and seven bark beetle species. Forest type had no significant effect on the abundance and species richness of ambrosia and bark beetles, while seasonal variation clearly shaped their assemblages, and both abundance and species richness were highest in spring. The similarity of ambrosia and bark beetle species composition observed in Japanese cedar forests and secondary broadleaf forests further suggests that both forest types may contribute to maintaining beetle assemblages in warm-temperate mixed forest landscapes in southern Japan. Furthermore, differences in ambrosia and bark beetle assemblages among seasons indicate the importance of multi-season monitoring to support the conservation of these beetles, given their ecological roles in wood decomposition within forest ecosystems. Implications for insect conservation: These findings suggest that both Japanese cedar forests and secondary broadleaf forests may provide important habitats for maintaining ambrosia and bark beetle diversity in warm-temperate mixed forest landscapes of southern Japan. Furthermore, multi-season monitoring is needed to accurately assess ambrosia and bark beetle diversity and to support biodiversity conservation and forest management, given their roles in wood decomposition although some species are significant pests.
The morphological concept of the purportedly rare eastern Nearctic stonefly species Leuctra monticola Hanson, 1941 (Plecoptera: Leuctridae) is redefined following examination of type material and integrated morphological-molecular phylogenetic analyses using mitochondrial cytochrome c oxidase subunit 1 gene sequence data. These analyses included L. alexanderi Hanson, 1941, a species with an overlapping geographic distribution in the southern Appalachian Mountains, USA, and occasionally confused with L. monticola due to incomplete original descriptions and inconsistent line drawing styles. This paper was predicated on the inclusion of L. monticola in the previous (2015) and current (2025) Virginia Wildlife Action Plans as a Tier 2 (= Very High Conservation Need) species despite a lack of published locality data. Moreover, L. monticola was included as one of 33 Regional Species of Greatest Conservation Need (RSGCN) in the 13 state Northeast US Fish and Wildlife Service (USFWS) region from Virginia north to Maine and holds a NatureServe G1 (= Critically Imperiled) global ranking. Formal conservation assessments are currently being conducted on all 33 project species and funded by the regional states and the USFWS. Our integrated morphological-molecular treatment that included L. alexanderi and L. monticola has led to the subsequent removal of the latter species from consideration as an RSGCN in the Northeast USFWS region. The distribution of L. monticola is narrowed to only foothill streams of the western flanks of the Great Smoky Mountains in east Tennessee, eliminated from the Virginia and North Carolina state lists, and aligns with the current NatureServe global ranking for this species. In contrast, L. alexanderi has a broad distribution in the Appalachian Mountains and adjacent Appalachian and Cumberland plateaus from northern Alabama east to northwestern South Carolina and north to southern New York. Digital light and scanning electron micrographs of diagnostic morphological characteristics of adult males and females of both species are provided, making correct determinations easier and geographic ranges more accurate. This paper has important ramifications for better decision making for potential conservation and management decisions, especially since L. monticola is now considered a species endemic to Tennessee and the Southeast USFWS region.
Forest-grassland mosaics are phytophysiognomies of grassland and forest ecosystems that create strong environmental contrasts, influencing species distribution in biomes like the Pampa of Southern Brazil. Our study analyses the structure of fruit-feeding butterfly (Nymphalidae) assemblages across natural mosaics of native grasslands and forest fragments in the Pampa biome in relation to butterfly abundance, species richness and composition in forest and grassland habitats across six localities. Our results show that forest habitats generally support higher richness and abundance, and harbor distinct butterfly communities compared to native grasslands. Species composition clearly segregated the two habitats, reflecting differences in environmental conditions, structural heterogeneity, and resource availability. Forests supported more taxonomically diverse assemblages due to vertical stratification and microclimatic heterogeneity, although local disturbances like cattle grazing and flooding could impact diversity. The dominance of the Satyrini tribe, particularly in disturbed forest fragments, suggests that anthropogenic impacts simplify forest structure, favoring disturbance-tolerant species. Native grasslands were also dominated by disturbance-tolerant Satyrini adapted to open conditions. The study demonstrates that habitat type strongly structures fruit-feeding butterfly assemblages and suggests that this group has the potential to serve as effective bioindicators for monitoring the impacts of land use in this heterogeneous landscape. Findings emphasize the urgent need to integrate both forest and grassland habitats into conservation policies, as each supports unique and distinct butterfly assemblages, collectively reflecting the ecological heterogeneity of the Pampa biome.
Coastal tiger beetles are highly vulnerable to habitat disturbance because of their strict microhabitat requirements and sedentary larval life history. Cicindela anchoralis, a critically endangered species in South Korea, has recently undergone severe population declines, yet the mechanisms linking habitat threats to its behavioral ecology remain poorly understood. In this study, we examined whether intrinsic behavioral traits of C. anchoralis contribute to its susceptibility to anthropogenic disturbance and natural inundation. We quantified oviposition burrow depth, larval burrow depth across developmental stages, larval soil moisture preference, and tolerance to complete immersion under laboratory conditions. Females deposited eggs at shallow depths (approximately 9 mm below the surface), rendering eggs highly susceptible to mechanical disturbance. Larvae constructed deep burrows averaging approximately 20 cm in depth, significantly deeper than those of a congeneric inland species, and consistently preferred moist substrates (5–10
Understanding long-term biodiversity dynamics is essential for effective conservation planning, yet historical baselines remain underexploited in insect studies. Here, we assess changes in butterfly (Lepidoptera: Rhopalocera) communities over nearly a century in a municipality in western France, using two complementary datasets: a historical collection sampled by a single naturalist between 1927 and 1933, and a modern dataset compiled between 2000 and 2025 from validated citizen science records and standardized surveys. A total of 59 species presence data were combined with a comprehensive life-history trait database to explore patterns of probable local extinction, persistence, and colonization. We document a moderate turnover around 27
Artificial light at night (ALAN) has been shown to negatively impact many species, particularly nocturnal ones, yet the underlying mechanisms driving these effects remain poorly understood. Various conservation measures have been proposed, including part-night lighting regimes and the dimming of artificial lights, but their effectiveness depends on how artificial light affects behaviour at a mechanistic level. In this study, we investigated how such temporary exposure to artificial illumination affects mate-finding success in the European common glow-worm, Lampyris noctiluca (Linnaeus, 1758), a nocturnal bioluminescent beetle. We examined the effects of different light intensities and exposure times on male mate-searching behaviour, in a controlled indoor arena setup, where males could move freely toward a dummy female. Temporary exposure to strong white light (100 lx and 4315 lx) at the onset of the activity period was associated with a reduced mate-finding success and a delay in the onset of mate searching, while the 10 lx treatment had no detectable effect. We suggest that this latency may reflect the time required for dark adaptation of the eyes following light exposure. In addition, under very bright light (4315 lx), males appeared to experience a reduction of activity at the beginning of the trial, possibly as a lingering inhibitory effect of the light exposure. As a result, their overall mate-searching period was reduced: males were less active at the beginning of their activity window and ceased searching at the same time as control individuals that had not been exposed to artificial light. These findings indicate potential limitations of part-night lighting regimes might not be fully effective as mitigation strategies when behavioural responses such as dark adaptation are involved. Nevertheless, they are preferable to no light reduction at all. Our findings also underscore the importance of considering both light intensity and timing when developing conservation strategies. Still, we should remain cautious when extrapolating laboratory results to ecological interventions intended as conservation measures. Our findings indicate that even temporary exposure to artificial light can disrupt mate-finding behaviour in glow-worms. Effective mitigation strategies must consider both the intensity and timing of artificial light to reduce its ecological impact.
Long-term monitoring is essential for understanding temporal variability and change in insect populations, yet such datasets remain scarce, particularly at high latitudes. Moths (Lepidoptera) are widely used as indicators of environmental change, but baseline information from northern island ecosystems such as Iceland has been limited. Here, we present results from a standardised moth monitoring programme conducted at five locations across southern Iceland between 1995 and 2024 using consistent light trap sampling. This enabled assessment of temporal variation in abundance, species richness and community structure at annual and site-specific scales. Moth abundance and species richness fluctuated markedly among years and sites, with pronounced interannual variability but no consistent long-term directional trend. Assemblages were characterised by strongly uneven dominance, with a small number of families accounting for most individuals alongside many infrequently recorded species. Temporal patterns were broadly similar across sites, although local differences in magnitude and timing were evident. This study establishes the first long-term baseline for moth communities from monitored sites in Iceland and highlights the importance of sustained, standardised monitoring for understanding insect dynamics in highly variable northern environments. The dataset provides a foundation for future analyses of environmental drivers and community change. Long-term standardised monitoring provides essential baseline information for detecting future changes in insect populations. The dataset provides a critical reference for future monitoring of moth communities in Iceland and will support future conservation assessments and biodiversity monitoring in high-latitude ecosystems.
Understanding thermal responses in ectotherms is key to assessing vulnerability to climate change. Tarantulas (Theraphosidae) are informative models due to their sedentary lifestyle, long life cycles, and reliance on specific microhabitats. We present the first integrative assessment of the thermal ecology of Plesiopelma longisternale, a widespread Argentine species, combining experimentally derived thermal limits and thermal preferences with species distribution models, and compare its thermal profile with the sympatric Grammostola vachoni to explore patterns of thermal niche differentiation. Plesiopelma longisternale showed a minimum thermal limit near 4 °C, a maximum near 44 °C, a thermal optimum of 29.5 °C, a narrow thermal performance breadth, and a preferred temperature of approximately 32 °C. Models integrating climatic and thermal parameters predicted strong reductions in climatically suitable habitat under future warming scenarios, exceeding 70
Bees play an important role as pollinators, and evidence of global bee population declines has become increasingly common. While most studies of plant-pollinator networks focus on contemporary ecosystems, historical interaction datasets remain rare, particularly in tropical regions. Here, we revisited a historical dataset of plant-bee interactions collected between 1971 and 1975 in a cerrado area from southeastern Brazil that was later converted by land-use change. Using this dataset, we described the structure of a historical plant-bee interaction network and examined how bee functional traits, such as body size, social organization, and floral resource use, were associated with species’ topological roles within the network. The network revealed: (i) a core of highly connected bee species, primarily natives; (ii) peripheral bees associated with distinct floral resources; (iii) a highly heterogeneous and compartmentalized organization of interactions; (iv) high interaction specificity; and (v) a weak relationship between bee functional traits and network topological roles. Together, these findings provide a rare descriptive record of a historical cerrado bee-flower visitation network and preserve ecological information from a plant-bee interaction system that can no longer be directly resampled. Historical interaction datasets such as this provide valuable ecological baselines for future comparative studies and can directly support conservation planning, ecological restoration, and biodiversity monitoring. Historical interaction networks help identify key pollinator and plant species that historically contributed to ecosystem organization, provide reference conditions against which restoration success can be evaluated, and contribute to the development of interaction-based indicators of ecosystem functioning. As historical datasets accumulate, they may also become important components of long-term ecological databases supporting conservation policies and restoration planning in highly threatened ecosystems such as the Brazilian Cerrado.
Climate change is reshaping species distributions and habitat suitability, presenting particular challenges for habitat-specialist species with limited dispersal ability and strong ecological dependencies. The small blue butterfly (Cupido minimus) is a habitat-specialist that is rare and localised in Scotland, where it relies on kidney vetch (Anthyllis vulneraria) as its sole larval host plant. This study uses MaxEnt-based integrative species distribution modelling to assess how climate change may affect future habitat suitability for the small blue in Scotland, while incorporating environmental predictors and host-plant suitability, with a post-model assessment of coastal erosion risk. The results suggest that suitable habitat for small blue is likely to shift inland under future high-emission climate scenarios, with substantial declines in coastal suitability by the late 21st century. Climate-driven shifts in habitat may create a mismatch between the location of environmentally-favourable areas, host-plant availability, and existing populations. For coastal populations, rising sea levels and shoreline erosion may further reduce or fragment the narrow strips of grassland and dune habitats on which the small blue depends. Including non-climatic and biotic predictors helped produce more ecologically constrained projections, while more complex models may reduce the relative contribution of key climatic variables. This study demonstrates how combining climate, biotic, and coastal-change information can support spatially explicit conservation planning for coastal populations of threatened insects. Forward planning for the conservation of the small blue will be required as potential inland habitat expansions, whilst providing a lifeline for this butterfly, are uncertain and may depend on kidney vetch availability, habitat connectivity and successful colonisation. For the small blue butterfly, adaptive conservation strategies in response to shifting habitats will be essential to support its long-term persistence.
Understanding how subterranean communities are structured requires evaluating both local ecological processes within caves and the broader environmental context in which they occur. In this study, we examined patterns of species richness, composition, and beta diversity of terrestrial invertebrates in two large carbonate caves located at contrasting elevations: Umajalanta Cave in Bolivia (2850 m a.s.l.) and Morena Cave in Brazil (794 m a.s.l.). Despite their distinct altitudinal settings, both caves share broadly comparable structural features, including extensive passages, stream systems, and relatively complex internal topology. Environmental variables related to habitat heterogeneity, trophic resource availability, microclimatic conditions, and distance from the entrance were measured in 23 sectors (mesoscale, 3 × 10 m) and 69 quadrats (microscale, 1 × 1 m). Invertebrates were sampled through active visual searches. At the mesoscale, none of the environmental variables evaluated exhibited a significant relationship with species richness in Umajalanta Cave. In contrast, species richness in Morena Cave was positively associated with substrate diversity and trophic resource availability. At the microscale, species richness increased significantly with increasing distance from the cave entrance in both systems. However, positive relationships between richness and the availability of trophic resources and shelters were detected exclusively in Morena Cave. Beta diversity was high in both caves and across spatial scales, driven primarily by species turnover and indicating strong compositional heterogeneity at the mesoscale and microscale. Overall, our results indicate that cave invertebrate assemblages are primarily structured by local ecological processes operating within caves rather than by the altitudinal context in which they occur, although this inference should be interpreted cautiously given that only two caves were analyzed. These findings underscore the importance of local environmental conditions and habitat heterogeneity in structuring subterranean communities, reinforcing the need to preserve both environmental integrity and habitat diversity within subterranean ecosystems.
Biodiversity knowledge in tropical regions remains limited due to incomplete species inventories and strong spatial and temporal sampling biases, particularly for diverse and ecologically important groups such as bees. Bees are key pollinators whose diversity is well documented in temperate and xeric regions but remains poorly understood in tropical biomes such as seasonally dry tropical forests (SDTFs). This biome is among the most threatened in the Neotropics and may harbor substantial, yet under-documented, bee diversity. Here, we provide the first comprehensive assessment of bee richness across Neotropical SDTFs by integrating occurrence data from GBIF and literature and evaluating two alternative biome delimitations (DRYFLOR and TEOW). We compiled 1,851 species and 250 genera in DRYFLOR and 1,424 species and 201 genera in TEOW, representing 28–37
Understanding the ecological mechanisms limiting population persistence is essential for the conservation of highly specialised and endangered insects. Tomares nogelii dobrogensis is one of the rarest butterflies in Europe and is strictly monophagous on Astragalus ponticus in Romania. Despite its high conservation relevance, quantitative data on its ecology and life history have been largely lacking. During the 2025 flight season, an extensive field study in northern Dobrogea, Romania, investigated phenology, adult lifespan, behaviour, habitat characteristics and host-plant synchrony across six colonies. Patch-level analyses were used to assess how habitat structure, light availability and host plant phenology influenced adult abundance. Oviposition patterns and preadult stages were documented. Adult flight activity closely overlapped with the reproductive phenology of A. ponticus, with peak butterfly abundance coinciding with bud formation and flowering. Observed adult lifespan was short, resulting in a narrow reproductive window. At the patch scale, butterfly abundance increased strongly with host-plant patch area and light availability, while host plant density alone was not a significant predictor. Oviposition was highly aggregated among host plants, occasionally leading to high larval densities and cannibalism. Our results indicate that population performance of T. n. dobrogensis is primarily constrained by the spatial and temporal availability of suitable host plant stages. Conservation management should therefore prioritise the maintenance of large, open A. ponticus patches and minimise disturbances by livestock during the flight and larval feeding periods. In addition, illegal collecting, which represents a significant threat to the species, must be prevented, e.g. by strict admission controls during flight and larval time.
Diponthus crassus is a grasshopper distributed across Argentina, Brazil, and Paraguay, and despite its broad geographic range, little is known about its habitat preferences, climatic requirements, or vulnerability to land‑use change. Understanding how climate and landscape structure jointly shape its distribution is crucial to assess extinction risk and guide conservation planning. We compiled 152 occurrence records (1985–2022) and modeled the species’ climatic and landscape suitability using eight algorithms within an ensemble modeling framework. Climatic predictors were combined with seven land‑use/land‑cover metrics to classify areas into four suitability categories (+/+ favorable climate and landscape; +/- favorable climate only; -/+ favorable landscape only; -/- neither favorable). Habitat loss was quantified by comparing historical potential suitability (assuming no human land‑cover change) with current conditions. We also evaluated the overlap between fully suitable habitats and protected areas. Historical fully suitable habitats (+/+) totaled 184,364 km², but only 41,814 km² remain today, representing a 77
Understanding how landscape structure influences species distribution is essential for biodiversity conservation in fragmented habitats. We investigated the spatial ecology of the two-tailed pasha, Charaxes jasius (Linnaeus), an emblematic Mediterranean butterfly whose larvae feed almost exclusively on the strawberry tree (Arbutus unedo L.). Using 1666 bait traps deployed over seven years at a regional level across a heterogeneous landscape in south-western Iberia, we modelled both abundance and occupancy in relation to host plant cover at eight spatial scales, functional connectivity, distance to the nearest host patch and forest habitat type. Connectivity was estimated using Hanski’s index, considering host patches as sources and traps as ecological sinks, thereby capturing a continuous gradient of host influence across the landscape. Our multi-model inference showed that occupancy was negatively related to distance from the nearest host plant patch and positively to host plant cover. The effect of host plant cover was the strongest at spatial scales of 5–6 km. Occupancy was also significantly higher in cork oak and Pyrenean oak than in Holm-oak woodlands. Non-zero abundance was significantly positively related to functional connectivity. Random effects of district and year highlighted the relevance of spatial and temporal variability. Most individuals were recorded close to host plant patches, but a small fraction occurred at greater distances, extending up to 5–20 km. Our findings underscore the importance of the distribution of the host plant but also broader landscape-scale configuration—including non-host patches that may provide critical adult resources—when assessing spatial habitat use by C. jasius in fragmented ecosystems, with key implications for management/conservation planning.
Pseudochazara williamsi ranks among the most threatened butterfly species in Europe and globally is currently listed as Critically Endangered in the 2025 Red List of European Butterflies. In study we analyze the status of the species through the compilation and validation of historical records, as well as field surveys conducted between 2023 and 2025. Endemic to the high mountain ranges of the southeastern Iberian Peninsula, the species has experienced documented extinctions of several local populations, accompanied by a pronounced decline in overall abundance. Moreover, its altitudinal distribution has undergone a substantial contraction, with the mean elevation of occupied sites shifting upward by 217 m when comparing data gathered during the present century with historical records from the last century. Marked changes in phenology have also been detected, most notably a shortening of the flight period driven by a contraction at the end of the season and a slight delay in its onset. In parallel, the species’ potential distribution area has declined dramatically, with an estimated reduction of 92.05
Veteran oaks are vitally important for saproxylic beetles due to the diversity of tree-related microhabitats they contain which have developed over centuries. Veteran oaks are however in decline across Europe. Veteranisation is a conservation tool that aims to create or speed up the formation of these rare microhabitats, potentially helping to mitigate losses, although empirical studies on the effectiveness of veteranisation are still very rare. We compared flight interception trapped beetle assemblages from 2-year old veteranised cavities in young oaks (2 methods: ‘nestbox with topping’ – NBT (n = 28) and ‘woodpecker hole’ – WPH (n = 26), with untreated control trees (n = 29) across 14 sites in southern Sweden. In total, 13010 individuals representing 493 beetle species were identified, of which 315 were saproxylic. The trapped beetles were assigned into one of four guilds with respect to their ecological association with wood (‘wood-living’, ‘partly wood-living’, ‘associated with wood living fungi’ and ‘other, non-saproxylic’). Both NBT and WPH supported significantly higher numbers of species and individuals than controls, particularly within the wood-living guild. Species such as Cryptarcha undata, Haploglossa villosula, and Quedius mesomelinus were abundant, reflecting an early-successional community. The presence of Lymexylon navale (NT) and Carphacis striatus (VU) indicates that the cavities provide ecologically relevant cues, even though reproduction could not yet be confirmed. No significant differences were detected between the two cavity types, suggesting that exposure of fresh wood and cavity creation alone are key drivers of early attraction. Our findings demonstrate that artificial cavities can rapidly increase habitat value for saproxylic beetles in young oaks, contributing to the restoration of oak sites. Artificially created cavities in young oaks can rapidly attract saproxylic beetles. Such interventions can help alleviate the current scarcity of natural tree hollows, thereby reducing future extinction risks for saproxylic beetles associated.
