The selection of Gentiana asclepiadea for this comparative study was driven by two primary factors. First, the research team had previously collected detailed data on this specific plant and its pollinators in the 1990s, providing a robust baseline for comparison. Second, as a montane species growing at altitudes between 1500 and 1900 meters, it was hypothesized to be less exposed to the immediate threats of habitat destruction and agricultural chemicals that plague lowland pollinators. The plant is a perennial with thick, branched rhizomes and straight, non-branched stems that can reach up to 80 centimeters in height. Its funnel-shaped flowers, which are not capable of spontaneous self-pollination, rely heavily on specific insect vectors for reproduction, making them an ideal indicator species for assessing pollinator health.

The field investigations were conducted at three specific study sites in Mt. Vitosha, a mountain range located near Sofia. Sites one and two were situated in open woodlands within the coniferous forest belt, while site three was located in subalpine meadows just above the tree line. Observations took place during the flowering seasons of August and September in both the 1990-1994 period and the 2017-2020 period. The researchers spent a total of 66 hours over 48 days observing bumblebee activity under various meteorological conditions. To avoid altering the natural behavior of the insects, the team refrained from collecting specimens, relying instead on visual identification and recording of visitation rates and behavior.

Identifying bumblebee species in the field presented certain challenges, particularly for species with similar coloration. For instance, Bombus wurflenii and Bombus lapidarius, though belonging to different subgenera and possessing different ecological niches, are difficult to distinguish with certainty in the field. Similarly, Bombus hortorum and Bombus subterraneus, as well as Bombus lucorum and Bombus terrestris, were often recorded as undistinguished pairs. To maintain scientific rigor while acknowledging these limitations, the researchers used an approximate approach in their data analysis. A pollinator activity index was calculated by dividing the number of pollinators recorded by the minutes of observation, multiplied by 60, providing a standardized metric for comparison across years and sites.

The results indicated that the species composition of bumblebees visiting the Gentiana flowers remained largely consistent between the two study periods. The primary visitors included Bombus pascuorum, Bombus pratorum, and the aforementioned undistinguished pairs. However, a slight but notable decline in overall bumblebee activity was observed in the 2017-2020 period compared to the 1990-1994 baseline. Linear regression analyses, while limited by the significant time gap between the two observation periods, showed decreasing trends in total activity at all three study sites. This decline was not uniform; fluctuations were observed within years and between sites, likely influenced by local colony dynamics, foraging ranges, and the presence of competing floral resources.

The reproductive success of the Gentiana plants mirrored the trends in pollinator activity. The researchers tested free pollination fruit set by monitoring 100 flowers each year for the development of fruit capsules. They also assessed seed set by counting matured seeds and non-fertilized ovules in 10 fruit capsules annually. A slight decrease in both fruit set and seed set was recorded during the final four years of the study. This correlation suggests that the reduction in bumblebee visits directly impacted the plant’s ability to reproduce, highlighting the critical role these insects play in the life cycle of this medicinal species. The data underscores that even minor changes in pollinator abundance can have measurable effects on plant reproductive output.

Several ecological factors may contribute to the observed fluctuations and declines in bumblebee activity. The study notes that the foraging range of bumblebees can extend up to 10 kilometers, meaning that local populations may be influenced by conditions in surrounding areas. Colony failure rates are known to be high, with fewer than 30% of Bombus pascuorum colonies producing new queens, and success rates even lower for other species. At site three, the subalpine meadow, fewer bumblebees were recorded, possibly due to competition from large populations of Epilobium angustifolium and Solidago virgaurea, which are known to attract bumblebees. This competition for pollinators may have reduced the frequency of visits to the Gentiana flowers, further impacting seed set.

Behavioral observations also provided insights into the interactions between bumblebees and the plant. In 1991, high activity of male Bombus hortorum or Bombus subterraneus was recorded in early September, likely due to their phenology and the timing of colony life cycles. In 2017, high activity of Bombus wurflenii at site two was attributed to nectar robbing behavior, where workers extract nectar by making holes in the base of the corolla tube. While nectar robbing can have negative, neutral, or positive effects on plants, in this case, it was considered neutral to slightly positive, as the workers still pollinated the flowers while attempting to access the nectar through the normal route. These behavioral nuances highlight the complex nature of plant-pollinator interactions and the importance of detailed field observations.

The study concludes that the slight decline in bumblebee activity and subsequent reduction in fruit and seed set demonstrate that negative effects on pollinators are detectable even in mountain habitats with fewer direct hazards. This finding aligns with broader research, such as a study showing a 76% decline in insect biomass in German nature reserves between 1989 and 2016. While the specific causes of the decline in the Vitosha Mountains are not definitively established, the authors speculate that urbanization of the foothills and increased agricultural activity in the surrounding lowlands may play a role. Additionally, climate change is a known hazard for certain bumblebee species, potentially driving them to higher altitudes, though the study lacks sufficient data for definitive conclusions on this factor. The research emphasizes the need for continued long-term monitoring of pollinators in diverse habitats to fully understand the drivers of their decline and to develop effective conservation strategies.

Subject of Research: Long-term monitoring of bumblebee pollination and reproductive success in Gentiana asclepiadea in Mt. Vitosha, Bulgaria.

Article Title: Monitoring bumblebee pollinator visits to the medicinal plant Gentiana asclepiadea L. (Gentianacese) – a comparison between the periods 1990–1994 and 2017–2020

Article References: Kozuharova, E., & Simeonov, V. (2022). Monitoring bumblebee pollinator visits to the medicinal plant Gentiana asclepiadea L. (Gentianacese) – a comparison between the periods 1990–1994 and 2017–2020. BioRisk, 17, 317-327. https://doi.org/10.3897/biorisk.17.76577

Image Credits: AI Generated

DOI: 10.3897/biorisk.17.76577

Keywords: bumblebees, pollination, Gentiana asclepiadea, insect decline, montane habitats, Bulgaria, long-term monitoring, ecology, reproductive success, bioindicators, Monitoring, bumblebee

The choice of Sion as the venue for the 2025 annual meeting carried a certain symbolic weight, since the host institution, HES-SO Valais-Wallis, sits at the heart of one of the driest and warmest regions of Switzerland, a landscape whose insect communities differ markedly from those of the Swiss Plateau or the higher Alps. The Valais has long been recognised as a hotspot for thermophilic species, including many that reach their northern distributional limits in the sunny slopes above the Rhône valley, and several of the talks delivered during the meeting touched directly on questions that arise from this regional context, such as the establishment of the Japanese beetle in the canton and the spread of the tiger mosquito into newly suitable habitats. Holding the meeting in Sion therefore offered participants not only a well-organised setting thanks to Andreas Sanchez and his team, but also a reminder that entomological research in Switzerland is increasingly shaped by processes unfolding at the southern, warmer edges of the country.

The opening keynote by Tanja Schwander of the University of Lausanne provided a conceptual frame for much of what followed, because the question of why sexual reproduction persists despite its apparent costs is one of the oldest and most stubborn problems in evolutionary biology. From a purely arithmetic standpoint, an asexual female that produces only daughters should enjoy a twofold reproductive advantage over a sexual female whose offspring are divided between sons and daughters, a discrepancy often described in the literature as the cost of males. Add to this the energetic expenses of finding mates, the risks of mating itself, and the slower intrinsic rate of increase of sexual populations, and the puzzle becomes sharper: sex should, in theory, be weeded out by natural selection, yet it dominates the animal kingdom. Schwander’s survey of the extraordinary diversity of insect reproductive systems, encompassing parthenogenesis, pseudogamy, hermaphroditism, hybridogenesis and androgenesis, illustrated why insects have become the premier model group for tackling this question. No comparable vertebrate group exhibits such a rich palette of reproductive modes, and the fact that many of these systems have evolved independently and repeatedly across the insect tree of life suggests that transitions between sexual and asexual reproduction are neither vanishingly rare nor biologically trivial.

The comparative experiments described in the keynote, involving thrips, mayflies and stick insects, reflect a broader methodological trend in which closely related sexual and asexual lineages are treated as natural replicates, allowing researchers to ask what asexual lineages lose and what sexual lineages gain over evolutionary time. The findings from the stick insect genus Timema, in which asexual species accumulated more deleterious mutations while sexual species showed more adaptive substitutions, align with theoretical expectations that sex helps purge harmful mutations through recombination and facilitates the fixation of beneficial allele combinations. Yet the keynote also made clear that the popular textbook answer, namely that sex generates the genetic variability needed to keep pace with changing environments, does not hold universally. The hypothesis that sexual lineages enjoy a survival advantage in more diverse habitats and under more variable environmental factors could not be confirmed in every comparison, a result that echoes a long-standing tension in the field between the elegance of theoretical models and the messiness of empirical data. The observation that some Drosophila lineages can spontaneously develop parthenogenesis, with eggs maturing without fertilisation, adds a further layer of interest, because it shows that the genetic machinery for asexual reproduction can lie dormant within otherwise sexual species and may surface under particular conditions, with implications for pest species in which a single asexual founder could in principle seed a new population.

Several of the shorter presentations on the Friday extended this evolutionary perspective into the realm of conservation and biogeography. Camille Cornet’s talk on the alpine butterfly genus Erebia highlighted a group that has become a flagship for alpine insect conservation, since these butterflies are largely restricted to high-elevation grasslands and are considered particularly sensitive to climate warming. The genus is species-rich in the Alps, and understanding how its members use and move through fragmented alpine landscapes is regarded as a prerequisite for designing effective protection measures. Eckehard Brockerhoff’s contribution brought an international comparison into the meeting, examining how land cover influences parasitism of the New Zealand red admiral butterfly, a reminder that questions about landscape structure and natural enemies are being pursued with similar methods on both sides of the globe. The phylogenomic work on Adephaga beetles presented by Cody Raul Cardenas addressed one of the largest suborders of beetles, a group that includes ground beetles and diving beetles, and whose internal relationships have proven difficult to resolve with morphology alone; integrative approaches combining genomic data with traditional characters are now reshaping this framework.

The talks on non-native species underscored how rapidly the composition of Switzerland’s insect fauna is changing. Stefano Bilotta’s retrospective and prospective view of the Japanese beetle in Valais concerned a pest that has caused enormous damage in North America and whose establishment in Europe is being monitored closely, with the canton of Valais among the first Swiss regions affected. José Ribeiro-Correia’s report on recently detected non-native ambrosia beetles and their fungal associates touched on a particularly insidious invasion pathway, because ambrosia beetles cultivate fungi inside the wood of their host trees, and it is often the fungus rather than the beetle itself that kills the tree. The global trade in wood products, packaging material and live plants has turned these tiny insects into one of the most successful groups of biological invaders worldwide, and their detection in Switzerland signals a growing surveillance challenge. Alexander Maess’s presentation on Lepidoptera range shifts and their interactions with host plants connected the invasion theme to climate-driven redistribution, since many moth and butterfly species are moving upslope and northwards, and the outcome of these shifts depends on whether their host plants are present in the newly colonised areas.

The Saturday programme, lacking a keynote and therefore richer in short presentations, showcased the institutional backbone of Swiss entomology. Inés Carrasquer Puyal’s talk on orthopteran phylogeny and genetic monitoring introduced the audience to multi-locus DNA barcoding, an approach that goes beyond the standard single-gene barcode by combining several genetic markers, thereby improving species discrimination and enabling population-level tracking. Jérémy Gauthier’s use of museomics, the extraction and analysis of genomic data from historical museum specimens, represents one of the most promising developments in biodiversity research, because natural history collections accumulated over the past two centuries now serve as archives of past genetic diversity. By comparing genomes of specimens collected throughout the twentieth century with those of living insects, researchers can reconstruct the timing and demographic signature of population declines that occurred long before systematic monitoring began, a perspective that is especially valuable for documenting the widely discussed insect decline.

The update on the Swiss Diptera checklist presented by Lisa Fisler connected directly to Fauna Helvetica volume 35, whose publication was reported at the general assembly. The growth of the checklist from 6,088 species in the 1998 first edition to 7,514 species in the new version illustrates how faunistic knowledge advances not only through new arrivals but also through taxonomic revisions, improved identification tools and intensified sampling, with 55 authors contributing to the revised volume. Jean-Luc Gattolliat’s provocatively titled talk on mayflies and politics made the case that even ephemeral insects, whose adult lives may last only days, have a role to play in policy debates, since mayfly larvae are sensitive indicators of water quality and their populations reflect the state of rivers and streams. Bärbel Koch’s representative study of saproxylic beetles in Ticino addressed a group whose dependence on dead wood makes them vulnerable to modern forestry practices, and such regional studies provide the baseline data needed for red lists and habitat management. Christophe Praz’s roadmap for certifying species knowledge in Switzerland responded to a practical concern that runs through many natural history societies: the pool of experts able to identify difficult insect groups is ageing, and structured certification of taxonomic competence is seen as one way to secure this expertise for the future. Camille Pitteloud’s account of the tiger mosquito in Valais closed the scientific programme with a public-health perspective, as the Asian tiger mosquito is not only a nuisance but a potential vector of diseases such as dengue and chikungunya, and its progressive establishment in Swiss valleys requires coordinated monitoring.

The business transacted at the general assembly offered a window into the society’s operations. The approval of the 2024 minutes from Neuchâtel, the president’s report on administrative support from info fauna and the platform Biology of the Swiss Academy of Sciences, and the grants of 10,300 and 6,000 Swiss francs from SCNAT and the Biedermann-Mantel foundation respectively, documented the modest but essential funding on which volunteer-driven scientific societies depend. The treasurer’s figures revealed the real costs of scholarly publishing, with more than 14,500 Swiss francs paid to Pensoft for the open-access platform of Alpine Entomology and over 12,000 francs for the production of Fauna Helvetica, alongside printing costs and digitisation projects carried out with the ETH library, whose e-periodica portal now makes the society’s historical journal volumes freely accessible. The editor-in-chief’s report on the journal recorded fourteen articles totalling 168 pages in the eighth issue, an average time from submission to publication of roughly two months, and a doubling of the journal impact factor from 0.4 to 0.8, figures that, while modest by international standards, reflect a healthy trajectory for a specialised regional journal. The choice of Rhyssa persuasoria, the giant woodwasp parasitoid, as Insect of the Year 2025 fitted the society’s outreach strategy, since the insect’s long ovipositor and its role in regulating woodwasp larvae make it a compelling ambassador for the ecological services provided by parasitoid wasps, a group that is species-rich in Switzerland yet largely invisible to the public. Taken together, the meeting in Sion demonstrated how a national entomological society functions simultaneously as a scientific forum, a custodian of faunistic data, a publisher, and an advocate for insects in public discourse.

Subject of Research: Insect biodiversity research and society affairs presented at the Swiss Entomological Society's 2025 annual meeting in Sion

Article Title: Protokoll der Jahresversammlung der Schweizerischen Entomologischen Gesellschaft vom 7. und 8. März 2025 an der HES-SO Valais-Wallis in Sion

Article References: Neumann, M. (2025). Protokoll der Jahresversammlung der Schweizerischen Entomologischen Gesellschaft vom 7. und 8. März 2025 an der HES-SO Valais-Wallis in Sion. Alpine Entomology, 9, 173-176. https://doi.org/10.3897/alpento.9.178557

Image Credits: AI Generated

DOI: 10.3897/alpento.9.178557

Keywords: Swiss Entomological Society, entomology, insect reproduction, parthenogenesis, alpine butterflies, ambrosia beetles, invasive species, biodiversity, Fauna Helvetica, Alpine Entomology, insect decline, Switzerland

The research, published in PLOS Neglected Tropical Diseases, was led by László Zsolt Garamszegi and colleagues, who designed a rigorous field experiment to quantify, for the first time under real Central European conditions, how ULV spraying affects both target mosquitoes and the broader community of flying insects that share the same air. Rather than simply comparing sprayed and unsprayed areas at a single moment, the team employed a before-after-control-impact design, abbreviated BACI, which is considered the gold standard for detecting environmental impacts in field studies. In this framework, researchers sample sites both before and after a disturbance occurs, and they do so at both impacted and control locations. This four-way comparison allows scientists to separate genuine treatment effects from natural fluctuations in insect abundance that would occur anyway due to weather, season, or chance.

The technical logic of the BACI design matters because insect populations are notoriously variable. Mosquito numbers can swing dramatically from one night to the next depending on temperature, humidity, and wind, so a naive before-and-after comparison at a single sprayed site could easily mistake natural decline for chemical kill. By pairing treated sites with untreated controls and measuring change in both, the researchers could isolate the signal of the insecticide itself. Mosquitoes were monitored using BG Sentinel traps, a widely used sampling device that mimics the visual and olfactory cues of a human host and is particularly effective at capturing Aedes species, including the invasive tiger mosquito. Non-target flying insects, meanwhile, were collected with malaise traps, tent-like passive structures that intercept insects as they move through the landscape and provide an unbiased sample of whatever happens to be flying by.

When the results came in, the good news for mosquito control was real but qualified. ULV treatment produced a significant reduction in mosquito abundance at treated sites, with an average decline of approximately 47 percent. That is a meaningful drop, and it confirms that the technology is not merely theater: the fog genuinely kills a substantial fraction of adult mosquitoes in the treated zone. Importantly, the decline was proportional across both native mosquito species and invasive newcomers such as Aedes albopictus, the Asian tiger mosquito, and Aedes koreicus, two species that have been steadily expanding their range into Europe and raise concern because of their ability to transmit diseases like dengue, chikungunya, and West Nile virus. From a purely operational standpoint, the sprayers were doing their job against both established and emerging threats.

However, the study also revealed that the effectiveness of ULV spraying is far from uniform. The reduction in mosquito numbers varied substantially from site to site, and two factors emerged as key influences: the initial abundance of mosquitoes before treatment and the wind conditions at the time of spraying. This makes intuitive sense from an application standpoint. ULV droplets are extremely small, typically in the range of a few tens of microns, which allows them to remain airborne and drift through vegetation where mosquitoes rest. But the same property makes them exquisitely sensitive to air movement. Where wind carried the droplets away from their intended target zone, or where mosquito populations were so dense that a single pass could not make a dent, the treatment underperformed. For municipal operators, this suggests that timing applications to calm conditions and calibrating expectations to local population levels could squeeze more value out of every spraying campaign.

The more troubling half of the story concerns what else was flying through that chemical fog. Malaise trap samples revealed a marked decline in non-target flying insects at treated sites, with reductions exceeding 40 percent across multiple taxonomic groups. The damage was not confined to a single vulnerable lineage; it swept broadly through the insect community, hitting small and medium-sized insects particularly hard. This size bias has a plausible mechanistic explanation: smaller insects have greater surface area relative to their body mass, so they absorb a lethal dose of insecticide more readily from contact with droplets, and their smaller energy reserves give them less capacity to survive sublethal exposure. The pattern also held when the researchers considered pollinator taxa as a group, a finding with obvious implications for ecosystems that depend on insect pollination services.

The scale of the non-target impact deserves careful interpretation. A 40 percent or greater short-term reduction in flying insects is not a trivial side effect, especially when it recurs across a growing season in which municipalities may spray repeatedly. Insects underpin food webs as prey for birds, bats, and fish, and they provide essential services including pollination, decomposition, and pest suppression. While the study measured short-term impacts and cannot by itself establish long-term population consequences, the magnitude of the immediate effect suggests that a single ULV application sends a substantial shock through the local insect community, one from which recovery must occur before the next application arrives. Whether repeated cycles of impact and recovery accumulate into lasting damage remains a critical open question for future research.

The findings arrive at a moment of heightened public anxiety about insect declines. Reports of falling insect biomass across Europe have made headlines worldwide, and conservationists have increasingly pointed to pesticide use as a contributing factor. Against that backdrop, the Hungarian study offers a rare piece of hard, quantitative evidence about one of the most common pest control interventions on the continent. It does not conclude that ULV spraying should be abandoned; the 47 percent reduction in mosquitoes, including disease-capable invasive species, represents a genuine public health benefit that cannot be dismissed. Instead, the authors frame the results as a trade-off: vector control and insect conservation are both legitimate goals, and current practice imposes real costs on the latter in pursuit of the former.

That framing points toward practical improvements rather than a simple verdict. If treatment effectiveness depends on wind conditions and initial mosquito abundance, then smarter application protocols, including monitoring-based triggering, weather-aware timing, and targeted treatment of breeding hotspots rather than blanket coverage, could reduce the total insecticide load while maintaining or even improving mosquito suppression. The similar proportional declines observed in native and invasive mosquitoes also suggest that the insecticide itself is not selective, meaning selectivity would have to come from where, when, and how much is sprayed rather than from the chemistry. Integrating ULV spraying into an integrated vector management strategy, alongside larval source reduction and biological controls, could shrink the collateral footprint of each campaign.

For residents of mosquito-prone towns, the study is a reminder that the reassuring fog rolling down the street is a double-edged instrument. It demonstrably cuts mosquito numbers, including the invasive species now knocking at Europe’s door, but it also cuts down a large share of everything else with wings, from pollinators to the tiny insects that feed the birds. As climate change pushes Aedes albopictus and Aedes koreicus further north and lengthens the season during which spraying seems necessary, the tension documented in this Hungarian field experiment will only intensify. The study’s lasting contribution is to replace anecdote with numbers, giving policymakers, municipal operators, and conservationists a common factual foundation for deciding how much mosquito control is worth, and what the rest of the insect world is being asked to pay for it.

Subject of Research: Field evaluation of ultra-low volume deltamethrin mosquito spraying on target and non-target insects in Hungary

Article Title: The effect of ULV-based mosquito control on target and non-target organisms in Hungary: An experimental field study

Article References: Garamszegi, L. Z., Nagy, G., Klein, Á., Szentiványi, T., Vásárhelyi, Z., Markó, G., Zsebők, S., & Soltész, Z. (2026). The effect of ULV-based mosquito control on target and non-target organisms in Hungary: An experimental field study. PLOS Neglected Tropical Diseases, 20(10), e0014140. https://doi.org/10.1371/journal.pntd.0014140

Image Credits: AI Generated

DOI: 10.1371/journal.pntd.0014140

Keywords: ULV spraying, deltamethrin, mosquito control, Aedes albopictus, Aedes koreicus, non-target insects, BACI design, pollinators, insect decline, vector management, Hungary, field experiment

The research team, working at the Gansu Gannan Grassland Ecosystem National Observation and Research Station at roughly 3,540 meters above sea level, set up five paired plots in June 2024. In each pair, one 5-by-5-meter plot was centered on an 8,000-kelvin white LED streetlamp mounted three meters above the ground, switched on nightly from 19:30 to 05:30 in step with local sunset, while the matching control plot held an identical unlit pole. The lit plots averaged 4.52 lux—right in line with local urban street lighting—whereas control plots stayed below 0.1 lux. From July through August, observers recorded flower visits at night with night-vision equipment and by day with standardized camera surveys, logging every insect that contacted the reproductive parts of a flower and identifying visitors to species or morphospecies using reference collections.

The scale of the dataset—2,160 nocturnal and 3,381 diurnal plant–pollinator interactions across 29 night-blooming and 40 day-blooming plant species—allowed the researchers to build quantitative interaction networks for each plot, time period, and replicate block, and to calculate three classic structural metrics: connectance, nestedness, and modularity. Connectance measures the density of links in a network, nestedness describes how specialist species interact with subsets of the partners of generalists, and modularity captures how strongly the network splits into isolated subgroups. Together, these metrics describe the architecture that underpins the stability and resilience of mutualistic communities.

At night, the effects were dramatic. Overall flower visitation fell by 35.4 percent under the lamps, driven overwhelmingly by moths: Lepidopteran visits collapsed by 57.5 percent, consistent with the well-documented phototactic behavior of nocturnal moths, which rely on celestial light cues for navigation and become disoriented, exhausted, or exposed to predators under artificial illumination. Yet the story was not one of simple loss. Dipteran visitation surged by 179.6 percent, largely on caraway (Carum carvi) and Bupleurum chinense, as typically day-active flies from families such as Tachinidae, Sarcophophidae, and Syrphidae extended their activity into the illuminated night. Beetles and bees showed no significant response.

These behavioral shifts translated directly into network reorganization. Nocturnal network nestedness plummeted by 64.7 percent, while modularity rose by 12.8 percent; connectance was unchanged. Statistically, the loss of nestedness tracked both total visitation and moth visitation under the lamps, supporting the idea that interaction structure is abundance-driven: as moths vanished from the illuminated flowers, the hierarchical fabric of the network frayed, and the opportunistic flies could not compensate. The rise in modularity, negatively correlated with visitation by both flies and moths, indicates that reduced activity by highly mobile pollinators weakened the links between subgroups, leaving a more compartmentalized community in which interactions concentrate within isolated clusters.

The functional stakes are considerable. Moths and flies differ in how effectively they transfer pollen, so a wholesale substitution of flies for moths may reduce pollination success even when visitation counts appear healthy. Previous work has shown that light pollution can cut pollination network nestedness severely and depress seed set in night-pollinated plants, and the new results reinforce the concern that ALAN does not just reshuffle who visits which flower—it may erode the reproductive output of entire plant communities, with consequences that compound over seasons.

What makes the study genuinely surprising is what happened during the day. Total diurnal visitation did not change significantly, but the composition of visitors shifted sharply: bees, butterflies, and beetles declined by 20.0, 51.8, and 61.7 percent respectively, while flies increased by 46.3 percent, partially offsetting the losses. Species-level contrasts pinpointed the winners and losers—bee visits dropped mainly on Oxytropis ochrocephala, butterfly visits on Anaphalis hancockii, and beetle visits on Stellera chamaejasme and Dasiphora fruticosa—while flies flocked to edelweiss-like Leontopodium, thistles, and Bupleurum. In other words, lamps burning only at night reorganized the daytime pollinator community.

Diurnal network structure shifted accordingly. Connectance rose by 16.1 percent, positively correlated with fly visitation and negatively with bee visitation, reflecting the generalized, multi-species foraging habits of Diptera: as flies took over, the network accumulated more links and became more densely connected, even as its modular and nested architecture stayed statistically intact. The authors propose several non-exclusive mechanisms for this cross-temporal carry-over. Artificial light can disrupt plant circadian regulation of nectar production and scent emission, altering when floral rewards become available and disadvantaging scent-dependent groups. It can also disturb the circadian rhythms or nocturnal larval stages of day-active insects such as butterflies. And because light-suppressed moths consume less nectar at night, a resource surplus may linger into the morning, favoring flexible daytime flies.

The choice of study system sharpens the message. Alpine meadows above 3,000 meters endure short growing seasons, pollen limitation, and heavy dependence on a few generalist pollinators such as bumblebees, leaving little slack for disruption. Although the Tibetan Plateau currently has the lowest light pollution levels in China, it has experienced the fastest growth of any region over recent decades, particularly in the east. Studying ALAN in this relatively pristine setting isolates the effect of light from the urban stressors—habitat loss, pesticides, heat—that usually confound light-pollution research near cities, and the results suggest that even remote ecosystems are vulnerable as lighting footprints expand.

The authors caution that their experiment captures responses over a single flowering season, and whether the observed structural shifts persist, accumulate, or trigger long-term declines in plant reproduction and pollinator populations remains an open question for multi-year studies. Still, the conclusion is difficult to escape: artificial light at night acts as a pervasive ecological disturbance that propagates through time, reorganizing mutualistic networks in both darkness and daylight. As global artificial lighting continues its rapid expansion, the researchers argue that conservation strategies must treat light pollution as a key environmental stressor in its own right, prioritizing optimized nighttime lighting regimes—dimmer, warmer, better shielded, and switched off where possible—to protect ecosystems that evolved under the rhythm of the stars.

Subject of Research: Effects of artificial light at night on nocturnal and diurnal plant–pollinator interaction networks in alpine meadows

Article Title: Artificial Light at Night Alters Both of Nocturnal and Diurnal Pollination Networks in Alpine Meadows

Article References: Lu, N., Wang, Y., Cai, W., Chen, Y., Yin, L., Chen, X., Cao, J., & Luo, Q. (2026). Artificial Light at Night Alters Both of Nocturnal and Diurnal Pollination Networks in Alpine Meadows. Ecology and Evolution, 16(10), Article e74368. https://doi.org/10.1002/ece3.74368

Image Credits: AI Generated

DOI: 10.1002/ece3.74368

Keywords: artificial light at night, light pollution, pollination networks, alpine meadows, moths, Diptera, plant–pollinator interactions, network ecology, Qinghai–Tibetan Plateau, nestedness, modularity, insect decline

The study focused on Volkhov, home to an aluminium smelter launched in 1932 and later replaced by a fertiliser plant, and Syasstroy, where a pulp and paper mill has operated since 1928. Both enterprises were designated regional pollution hot spots in the early 1990s by the Baltic Marine Environment Protection Commission. Volkhov’s emissions were dominated by sulphur dioxide and fluoride compounds, while Syasstroy released dust, sulphur dioxide, and nitrogen oxides. By the mid-1950s, peak sulphur dioxide concentrations in Volkhov had reached roughly 750 times the currently recommended health-protective level, and local ecosystems near Syasstroy were classified as critical or even catastrophic in the 1990s.

Over the study period, emissions fell dramatically. Sulphur dioxide output at Volkhov dropped fourfold between 1988 and 2021, fluorine emissions fell fifteenfold in the early 1990s, and dust emissions were about fifty percent lower in the 2020s than in the late 1980s. At Syasstroy, dust and sulphur dioxide emissions plummeted a hundredfold in the 1990s following an abrupt production decline. The researchers documented corresponding environmental recovery: fluoride concentrations in birch leaves near Volkhov fell from a peak of 200 micrograms per gram in 1988 to 32 micrograms per gram in 2025, and the needle longevity of Norway spruce, a reliable bioindicator of pollution stress, rebounded from roughly half of background values in 1989 to normal or even above-normal levels by 2025.

Against this backdrop of dramatic environmental change, the fate of the insects was surprisingly static. Between 1988 and 2025, the team counted more than 70,000 observation units of birch-feeding herbivores, representing over 60 species grouped into 24 recognisable taxonomic units, across 27 study sites and 9,674 sampled birch trees and branches. The community included external defoliators such as geometrid moths and sawflies, leafminers from several moth families, and leafrollers. Yet when the researchers correlated insect densities with distance from the polluters across all taxonomic-unit-by-year combinations, only 8.1 percent of 383 correlations were statistically significant, barely exceeding the 5 percent expected by chance alone.

A meta-analysis of the spatial patterns revealed that only six of the twenty analysed taxonomic units increased in density near the polluters, while the remaining fourteen showed no association with pollution at all. This variation was not explained by the insects’ abundance or by their feeding guild. During the high-emission years of 1988 to 1996, overall herbivore abundance did increase with proximity to the pollution sources, but the effect size was a mere 0.10, which is considered small by conventional statistical standards. Remarkably, during the low-emission period from 1997 to 2025, abundance continued to rise near the polluters at the same rate as before, even as the emissions that supposedly caused the pattern had largely vanished.

The persistence of elevated insect densities near the towns after emissions collapsed raises a thorny question: if pollution is not driving the pattern, what is? The authors considered urbanisation as an alternative explanation, but the towns are small, and existing meta-analyses suggest urbanisation has no significant overall effect on insect herbivore abundance. The results also cast doubt on earlier syntheses. A previous meta-analysis had reported elevated herbivore abundances near industrial sites, but the authors of the new study point out that mean effect sizes based on randomly chosen years from multiyear datasets did not differ from zero, whereas single-year studies and pseudoreplicated designs produced larger effects. In other words, earlier work may have systematically overestimated the true impact of pollution on herbivorous insects.

Perhaps the most counterintuitive finding concerns plant quality and leaf damage. Larvae of the autumnal moth, Epirrita autumnata, grew 45 percent faster on birch leaves collected in 2017 from sites closest to the polluters compared with leaves from the most distant sites, with the effect reaching 78 percent near Volkhov. Yet the density of this moth did not change with pollution level, and overall foliar damage by insects near both towns was approximately half of that recorded at unpolluted sites. This decoupling between plant quality, herbivore abundance, and plant damage echoes previous reports that improved host plant quality does not necessarily translate into more insects or more defoliation, because better foliage may simply allow insects to eat less while growing faster.

The study also speaks directly to the heated debate over global insect decline. Contrary to predictions, the researchers found no evidence that birch-feeding insects declined over the 38 years, either in polluted or unpolluted sites. Overall abundance remained flat, while diversity increased substantially at both polluted and background sites. The compositional shifts that did occur were guild-specific: leafminer densities decreased over time, defoliators remained stable, and leafrollers tended to increase, a pattern consistent with data from a copper-nickel smelter at Monchegorsk some 900 kilometres to the north. The rise in diversity is most plausibly explained by climate warming, with mean ambient temperature in the St. Petersburg region climbing from 5.7 to 6.7 degrees Celsius between 1985 and 2024, allowing southern species to expand northward.

The authors caution that their findings carry important limitations. The temporal resolution of sampling was uneven across years and taxa, emission and deposition data are incomplete for earlier decades, and the observational design cannot fully disentangle the effects of pollution decline from co-occurring drivers such as climate warming. The use of recognisable taxonomic units rather than species-level identifications may also mask responses of individual species that differ in pollution sensitivity. Nevertheless, the sheer duration and spatial extent of the dataset, with roughly 85 percent of the data collected by the two authors themselves, minimises the observer biases that plague shorter studies.

The broader implications are twofold. First, the study exposes a critical weakness in bioindication: conclusions about ecosystem health depend heavily on which indicator is chosen. Pollution gradients were clearly reflected in fluoride accumulation and spruce vigour, but insect density and diversity told a different and far noisier story, and a researcher relying on a single taxon in a single year could have concluded almost anything. Second, the work challenges the generality of the view that insects are universally sensitive to environmental change and questions the role of moderate industrial pollution as a driver of insect decline, at least for herbivores. The authors describe several of their findings as ecological surprises, unexpected observations that force a re-evaluation of established views. In an era when alarming insect decline headlines dominate the news, this nearly four-decade record from the boreal forests of northwestern Russia offers a sobering reminder that nature’s responses to human pressures are rarely as simple as we predict.

Subject of Research: Long-term effects of industrial air pollution and emission decline on birch-feeding insect communities in northwestern Russia

Article Title: Weak and inconsistent associations between birch-feeding insects and pollution levels around two industrial towns during substantial emission decline (1988–2025)

Article References: Kozlov, M. V., & Zverev, V. (2026). Weak and inconsistent associations between birch-feeding insects and pollution levels around two industrial towns during substantial emission decline (1988–2025). Environmental Monitoring and Assessment, 198(11), Article 1157. https://doi.org/10.1007/s10661-026-15971-1

Image Credits: AI Generated

DOI: 10.1007/s10661-026-15971-1

Keywords: industrial pollution, insect herbivores, birch, emission decline, ecosystem recovery, bioindicators, insect decline, leafminers, Epirrita autumnata, boreal forest, Norway spruce, long-term monitoring

The evidence assembled by the team ranges from the charming to the downright bizarre. Consider the Hoffmann’s two-toed sloth, whose shaggy coat hosts a miniature ecosystem. Sloth moths live out their lives in the animal’s fur, and their activities help cultivate algae that grow in the sloth’s hair — algae the sloth then eats, supplementing its otherwise meadow-sparse diet of leaves. In this sense, the sloth is not merely tolerating its insect tenants; it is actively farming them, or at least farming the garden they fertilize. Remove the moths, and the sloth loses both a nutrient source and a living camouflage that helps it vanish into the canopy.

Other examples reveal insects serving as tools, infrastructure, and even medicine. Chimpanzees have been observed applying insects to open wounds, a behavior that appears to help sterilize injuries and may represent a form of self-medication. Herons, meanwhile, have turned insects into fishing equipment, using them as bait to lure fish within striking distance. Birds and reptiles lay their eggs inside termite mounds, exploiting the structures’ remarkably stable internal temperatures as natural incubators. In arid environments, some desert frogs take refuge inside ant nests, where the humidity offers a buffer against desiccation in landscapes where water is the scarcest resource of all.

“Insects are sometimes called the ‘little things that run the world’ because they are so important to life on Earth,” said Grames, the paper’s co-lead author. “We often hear about their importance as pollinators, or decomposers, or food for insectivores like birds and bats, but we forget about all the other things they do for us and for other species.” That observation captures the review’s core ambition: to move beyond the well-worn categories of pollination and predation and catalog the full breadth of insect-vertebrate relationships, many of which fall through the cracks of conventional ecological research.

The project was a genuinely international undertaking, with authors drawn from eight countries. Alongside Grames, the review was co-led by Rob Cooke, an ecological modeler at the UK Centre for Ecology and Hydrology, and Chris Elphick, professor of ecology and evolutionary biology at the University of Connecticut. Additional Binghamton contributors included Lindsey Swierk, assistant professor of biological sciences, and biological sciences alumni Julianna Yager and Suyeon Jang. In a fitting touch, Jang — an undergraduate with a painting minor — created the paper’s main illustration as an independent study project, translating the review’s scientific breadth into a single visual statement.

The effort traces its origins to 2022, when researchers established the Status of Insects: An International Research Coordination Network, an initiative funded by the National Science Foundation. The network emerged directly from Grames’ doctoral work in Elphick’s laboratory, and it was designed to confront a persistent problem in entomology and ecology more broadly: the literature on insect-vertebrate interactions is scattered across hundreds of individual studies, each examining a narrow slice of the picture. By consolidating that dispersed evidence into a single synthesis, the review offers the most comprehensive account yet of how deeply vertebrate life is woven into the fabric of insect diversity.

The scale of that dependence is difficult to overstate. There are an estimated 14 to 30 million species of insects on Earth, and they underpin the health and function of ecosystems on nearly every continent. They feed species ranging from hummingbirds, whose metabolisms demand near-constant refueling, to grizzly bears, which gorge on moths and other insects during critical seasons. Insects also enable other food sources indirectly through pollination, and they produce substances — honeydew, honey, and wax among them — that are themselves consumed by other species. For many vertebrates, insect abundance is not a background condition but a calendar: a variety of species time their breeding seasons to coincide with seasonal pulses of insect availability, synchronizing reproduction with the brief windows when their young can be fed.

The review also documents subtler forms of dependence that border on engineering. Birds incorporate spider and insect silk into their nests, taking advantage of materials with tensile properties that few natural substances can match. Some birds go further, deliberately situating their nests near stinging insects such as wasps, recruiting the colony’s venomous defenses as a security system against predators. More than 200 bird species use crushed ants for grooming — a behavior known as anting, in which the birds rub ants over their plumage, likely benefiting from the insects’ chemical secretions. And the relationship between insects and nesting vertebrates stretches deep into the past: insects once lived inside dinosaur nests, cleaning them out, and according to Grames, they still perform that sanitation service today in the nests of some owls and kingfishers.

Yet for all this richness, the scientific literature has a conspicuous blind spot. Few studies consider how insect population declines affect vertebrate species beyond the most obvious channel — a shrinking food supply. That narrow framing, the authors argue, dramatically understates the risk. If insects disappear, vertebrates lose not only calories but nesting materials, incubators, medicines, sanitation services, climate refuges, and the ecological timing cues that structure their reproductive cycles. Some insect populations have experienced alarming declines in recent decades, and those losses will ultimately propagate through the vertebrate communities that depend on them in ways that current research has barely begun to measure.

The numbers behind that warning are stark. “We’re losing insects at a rate of about 1-2% per year,” Grames said. “When you scale that up across a few decades, we’re talking about a major change to ecosystems. Insect conservation should be a top priority for anyone worried about the future of biodiversity.” A decline of even one to two percent annually, compounded over half a century, translates into a transformation of insect communities on a scale that has no precedent in recent ecological memory. Elphick, an ornithologist by training, framed the implication as a call for scientific bridge-building: he hopes the review will foster increased collaboration between scientists who study vertebrates and those who study insects. “If you want to have vertebrates, then you’ve got to be thinking about insect conservation, and we don’t do that nearly enough,” he said. In an era when conservation planning is often organized around charismatic vertebrates and their habitats, the review’s synthesis delivers a pointed reminder that the fates of sloths, songbirds, chimpanzees, and frogs are entangled with creatures small enough to escape notice — and that protecting the little things that run the world may be the surest way to protect everything that runs on them.

Subject of Research: The diverse roles of insect biodiversity in supporting vertebrate species

Article Title: Insects are essential to vertebrate life — as food, shelter and medicine

Article References: Insects are essential to vertebrate life — as food, shelter and medicine. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: insects, vertebrates, biodiversity, conservation, sloths, entomology, ecology, insect decline, termite mounds, chimpanzees, Nature Reviews Biodiversity, ecosystems

The experiment was designed around the biology of the fall webworm, a North American moth whose gregarious caterpillars spin the familiar silken tents seen on hundreds of tree and shrub species. The species is a true edge specialist: its webs appear along streams, forest margins, roadways, and sidewalks, precisely the places where humans install streetlights. Adults are short-lived, surviving roughly four days after emerging from their cocoons, and they do not feed. They are considered nocturnal and are thought to mate during twilight, often remaining in copulation past sunrise into the afternoon, which makes them an ideal subject for testing whether artificial illumination disrupts the narrow window in which reproduction must occur.

To run the test, the team, led by Mykaela M. Tanino-Springsteen and Shannon M. Murphy, used moths from a laboratory colony established in 2019 with wild larvae collected in Colorado and regularly supplemented with wild-caught individuals to maintain genetic diversity. Virgin, unrelated males and females were paired within twenty-four hours of eclosion and placed in clear plastic mating chambers. Each evening the chambers were moved to a partitioned greenhouse on the University of Denver campus, with half assigned to a room illuminated by ceiling-mounted high-pressure sodium luminaires, the same technology widely used in street lighting, and half to a room shielded from the lights and most surrounding urban skyglow. The lamps were programmed to switch on at 8:30 in the evening and off at 6:00 in the morning, mirroring the schedule of real streetlights in the surrounding Denver neighborhood.

The researchers deliberately avoided calling the darkened room a control, because even that side of the greenhouse received some ambient light pollution through its single wall of south-facing glass windows. The two rooms shared the same temperature and humidity, and the mating chambers were arranged in a single layer on benches about five feet below the light source, all equidistant from the lamps. The team also confirmed that the chambers retained heat equally in both rooms, ruling out thermal differences as an explanation for any behavioral divergence. Over four consecutive nights in late June 2023, the researchers checked each morning for mating pairs and recorded any deaths.

The mating result was dramatic. Of the seventy pairs in which both individuals survived the night, eighteen percent of those in ambient light mated, while zero percent of those under the streetlights did, a statistically significant difference detected with Pearson chi-square tests. Because fall webworms typically mate within a day when they are going to mate at all, and because they remain coupled after sunrise, the researchers were confident they were observing essentially all mating events. The complete shutdown of reproduction under artificial light suggests that these moths require low-light conditions to initiate copulation, and that the spectral signature and intensity of sodium streetlights are enough to suppress that behavior entirely.

Survival told a subtler story. Across all 186 moths analyzed, survival was 92.4 percent in the ambient treatment compared with 83 percent under ALAN, a trend that fell just short of conventional statistical significance with a p-value of 0.0512. Males and females did not differ in their survival responses. Recognizing that the near-significant result might reflect an underpowered sample, the team conducted a post-hoc power analysis, which showed that detecting a twenty percent difference would require about 148 moths per treatment, only modestly more than the 92 to 94 moths they actually tested. The authors caution that the probability of a type-II error is high and that ALAN likely does reduce survival, even though the effect size, a Cohen’s d of 0.29, is small.

Why would light at night block mating so completely? The study outlines two leading mechanistic hypotheses, neither yet tested directly in fall webworms. The first involves pheromones, the chemical signals female moths emit to attract males. In related work on the cabbage moth (Mamestra brassicae), researchers found that ALAN altered the chemical composition of female sex pheromones and reduced overall pheromone production, which could cripple mate attraction. The second involves circadian rhythms: for many moth species, the timing of female pheromone release, male responsiveness, and copulation is governed by a twenty-four-hour clock calibrated to natural light cues. If streetlights erase those cues, females may never call and males may never respond, leaving both sexes reproductively idle despite being physically capable of mating.

The survival effect, if confirmed, could arise through several pathways documented in other insects. Flight-to-light behavior, the fatal attraction that draws moths toward lamps, can exhaust individuals or expose them to predation, and previous work has shown it can be sex-biased in Lepidoptera. Short-wavelength blue light has proven lethal to fruit flies, flour beetles, and mosquitoes in laboratory studies, though the effects of different light spectra on fall webworms have never been examined. ALAN has also been shown to suppress melatonin production and impair immune function in crickets, and earlier research from the same Denver laboratory found that light pollution reduced the performance of a grass-feeding caterpillar both directly and indirectly, by altering host plant traits such as toughness and carbon-to-nitrogen ratios.

The population-level implications are significant. Because fall webworms concentrate along habitat edges, and because urban and rural edges are exactly where streetlights cluster, the species may face chronic exposure during its brief reproductive window. If moths cannot escape illuminated zones, the complete mating inhibition observed in the greenhouse could translate into local population declines in lit areas, with cascading effects on the predators and parasitoids that depend on fall webworm larvae for food. There is also a hint of evolutionary hope in the literature: urban ermine moth populations show reduced flight-to-light behavior compared with dark-sky populations, and corn earworm moths have become less likely to be caught in light traps over time, possibly an adaptive response to decades of light pollution. The Denver team’s colony, however, was sourced largely from rural, dark environments, and they plan to test whether urban fall webworms mate more readily under ALAN than their rural relatives.

The study also carries a notable human dimension: the experiment was conducted in partnership with middle school campers from the University of Denver’s DU SciTech summer camp, part of an ongoing series of authentic research experiences in which students help investigate how ALAN reshapes natural environments. As for the science itself, the authors emphasize that ALAN likely touches every life stage of the fall webworm. Larvae require photoperiod cues to enter diapause, and laboratory-reared larvae exposed to constant light fail to enter that dormant state, a potentially lethal mistake for insects facing a Colorado winter. But it is the adult finding that stands out most starkly. Reproduction is the bottleneck through which every population must pass, and this experiment shows that for one common, widespread moth, the simple presence of a streetlight is enough to bring it to a complete halt. As cities continue to brighten the night, the dark refuges that nocturnal insects depend on are shrinking, and studies like this one make clear that the consequences may be measured in generations that are never born.

Subject of Research: Effects of artificial light at night on mating and survival of the fall webworm moth

Article Title: Artificial light at night inhibits mating and may reduce survival in a nocturnal moth

Article References: Tanino-Springsteen, M. M., Hicks, K. G., Tinghitella, R. M., Hoffman, J. L., Welsh, G. T., Klingler, A. N., Vyas, D. K., Sellers, E. J., Reigrut, J. D., Dam, K., DeSoto, S. R., Houston, L., Giaritelli, S., Chapman, O. R., Bell, T. J., Smith, M. O., Rodriguez-Lewingdon, A. S., Moralez, M. E., Gifford, A., … Murphy, S. M. (2025). Artificial light at night inhibits mating and may reduce survival in a nocturnal moth. BMC Environmental Science, 2(1), Article 17. https://doi.org/10.1186/s44329-025-00030-w

Image Credits: AI Generated

DOI: 10.1186/s44329-025-00030-w

Keywords: artificial light at night, light pollution, fall webworm, Hyphantria cunea, moths, insect decline, mating behavior, pheromones, circadian rhythm, urban ecology, streetlights, Lepidoptera