Insect Decline Research Articles

Diversity and Flight Patterns of Caddisflies (Trichoptera) in an Atlantic Forest Fragment: Implications for Species Conservation in Threatened Ecosystems.

Anthropogenic activities have decimated the Atlantic Forest domain (AF) and increased the pressure on freshwater biota, such as Trichoptera, which is the most affected order by the current insect decline. Adult mobility is crucial for the colonisation of new environments unconnected by water sources. In this article, we describe the assemblage of caddisflies in a preserved AF fragment related to their functional feeding group and provide empirical data on the patterns of horizontal and vertical flight. Adults were collected using white sheet and light attraction traps, placed at different distances and heights from a stream in Pernambuco, Brazil. A total of 2934 specimens of 15 species from five families were collected, mostly collector-filterers. Horizontal flight was limited, with 80% of the abundance concentrated up to 20m. Vertical stratification was also concentrated at lower heights. A female-biased proportion was observed at higher strata. The richness and abundance of species decreased with increasing distances and heights from the stream. Overall, Chimarra sp. and Macrostemum scharfi were the dominant species. Trichoptera is a key taxon used as a biological indicator of water quality, and here, knowledge on the diversity and flight patterns of adults is expanded. At the risk of intensive pollution of rivers in Atlantic forests, data on the adult dispersal can be incorporated in the assessment of endangerment status and in conservation strategies.

Dutch landscapes have lost insect‐pollinated plants over the past 87 years

Abstract The interruption of plant‐pollinator interactions may threaten global plant diversity, food security and ecosystem stability. Recent reports of strong declines in both insects and plants point to insect decline as a driver of plant decline. However, it is still unknown whether these trends are related as plants often produce seeds without the need for insect pollinators, and to what extent insect‐pollinated plants have declined in relation to plants not pollinated by insects. In this study, we hypothesise that natural plant communities have shifted away from insect‐pollination. We combined 365,768 vegetation plots from 1930 to 2017 in the Netherlands and plant traits to assess the changes in occurrences of plants pollinated by different modes. Furthermore, we included key drivers in plant decline—specifically nitrogen, moisture and habitat types—as interaction factors to explore the persistence of the observed changes under different environmental conditions. The proportion of insect‐pollinated plants has declined while that of wind‐pollinated plants has increased over the last 87 years. This proportional change reflects an absolute decrease in the number of insect‐pollinated species and an increase in the number of wind‐pollinated species. Synthesis and applications. This study implies that Dutch landscapes are losing insect‐pollinated plant species, which is likely due, at least in part, to the decline in pollination services. Our results of quantifying the decline in insect‐pollinated plants support the necessity and urgency of taking conservation initiatives. Several management strategies and policy recommendations could be applied to alleviate the decline of insect‐pollinated plants and ensure crop safety. For example, conserving natural environments by reducing nitrogen deposition may support local plants and insect pollinators. Additionally, there is a particular need for focused efforts to protect natural grasslands, as these areas harbour many insect‐pollinated plants, which have experienced declines. Finally, monitoring and assessing the state of both pollinators and (insect‐pollinated) plants is needed to assess the progress of conservation measures. While recognising the interdependence of pollinators and pollinated plants, it is crucial to extend efforts beyond pollinator conservation alone to effectively safeguard insect‐pollinated plants and ensure crop safety.

High temporal resolution data reveal low bat and insect activity over managed meadows in central Europe

Increasing agriculture and pesticide use have led to declines in insect populations and biodiversity worldwide. In addition to insect diversity, it is also important to consider insect abundance, due to the importance of insects as food for species at higher trophic levels such as bats. We monitored spatiotemporal variation in abundance of nocturnal flying insects over meadows, a common open landscape structure in central Europe, and correlated it with bat feeding activity. Our most important result was that insect abundance was almost always extremely low. This was true regardless of management intensity of the different meadows monitored. We also found no correlation of insect abundance or the presence of insect swarms with bat feeding activity. This suggests that insect abundance over meadows was too low and insect swarms too rare for bats to risk expending energy to search for them. Meadows appeared to be poor habitat for nocturnal flying insects, and of low value as a foraging habitat for bats. Our study highlights the importance of long-term monitoring of insect abundance, especially at high temporal scales to identify and protect foraging habitats. This will become increasingly important given the rapid decline of insects.

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

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

DNA barcoding elucidates ecological dynamics regulating the diversity of Theretra, Hübner 1819 (Lepidoptera: Sphingidae) from northernmost Western Ghats

The study investigates the distribution and diversity of the old-world moth genus Theretra from the family Sphingidae in the Indian subcontinent. Through extensive data collection and molecular analysis from the Northernmost Western Ghats (Nashik District), seven species of Theretra were identified: T. alecto, T. castanea, T. clotho, T. gnoma, T. nessus, T. oldenlandiae, and T. sumatrensis.Molecular clustering identifies genetically similar specimens, which further helps to recognise similar ecological niches and the associated ecological drivers regulating the distribution pattern of similar specimens. A dataset of 196 published records from Barcode of Life Data Systems (BOLD), including outgroup and the sequences generated in the present study for the Indian species of Theretra, were compiled in a dataset ‘THEREIND’. The crucial role of monsoon and elevation in the diversity and distribution of these moths was comprehended using DNA barcoding and sequence clustering on BOLD. The comparisons suggested a strong correlation with either monsoon or elevation or both.In the purview of the sixth mass extinction and the first true extinction of insects, adequate information on the diversity and the factors affecting it would provide fundamental information to insinuate conservation strategies required for coping with continuous climatic changes.

The spider fauna of Danish coastal dune habitats revisited after 25 years: evidence of faunistic impoverishment

Arthropod faunas have become impoverished in recent years in abundance as well as in diversity, but so far little evidence exists concerning spiders. In 2022, we repeated pitfall trap collections of spider assemblages completed 25 years previously in coastal dune habitats of the Hanstholm Reserve of National Park Thy, Denmark. Traps were placed approximately at the same spots, i.e. the habitats (white dune, grey dune, dry dune heathland, wet dune heathland, low pine plantation) were represented approximately as before. Contrary to most previous reports of insect decline, we found only weak evidence of reduction in abundance, but strong indications of reductions in faunistic value based on changes in ecological traits. Within the same period of spring and with the same number of traps, we collected 12% fewer spider individuals and 13% fewer species; rarefaction indicated that the lowered species richness was real. Species diversity had decreased and dominance increased. Changes in indices of ecological traits showed that the fauna had changed into decreased contribution of habitat specialists and species of restricted Danish distribution; the proportion of aeronauts had increased; the average body size had decreased. Indices of assemblage microclimatic niche positions and niche widths showed increased representation of shade and humidity loving species. Most of these changes were repeated in each of the habitats. Finally, we found evidence of a phenological shift towards activity earlier in spring in some species.Implications for insect conservationWe discuss possible management measures to counteract the observed trend towards reduced faunistic value.

Contrasting patterns of habitat use in a threatened carabid (Carabus intricatus) and a sympatric congener in ancient temperate rainforest

Abstract There is increasing concern into the decline of insect populations, with corresponding calls for conservation action aimed towards threatened species in particular. However, there is a distinct paucity of knowledge surrounding habitat requirements, microhabitat selection and conservation actions that may be undertaken for the vast majority of invertebrate species. Carabus intricatus (Coleoptera: Carabidae) Linnaeus, 1761 is a threatened ancient woodland specialist in the United Kingdom with a highly restricted distribution and is listed as a section 41 species of principal importance in England. Despite this, no empirical systematic evidence exists for even basic habitat requirements. Here, we used a patch‐occupancy modelling framework to determine occupancy and detection parameters for C. intricatus and a sympatric generalist species, C. problematicus, which is a potential competitor. Our models showed that decayed deadwood availability and leaf litter covering (an indicator of the availability of mature broadleaved trees) leads to higher occupancy of C. intricatus, whereas decayed dead wood availability and slug abundance are primary determinants of overall abundance. Additionally, detection models showed that higher humidity substantially increased activity of C. intricatus. For C. problematicus, ground moss coverage and overall deadwood volume most strongly influenced occupancy and abundance, whereas there were no humidity related influences on activity. The results support our general predictions about the specialist–generalist nature of the two species in the United Kingdom and indicate that key characteristics of old‐growth temperate rain forests, particularly the availability of deadwood and high humidity, are central to the conservation of these charismatic carabids.

Illuminating arthropod diversity in a tropical forest: Assessing biodiversity by automatic light trapping and DNA metabarcoding

AbstractAlthough studies of insect decline have recently dominated headlines worldwide, their interpretation requires caution since for most species, we lack long‐term population baselines. In the tropics, where most insect species thrive, our knowledge is even more limited and so reliable insect assessments must originate from well‐established long‐term monitoring efforts. Combining the extensive monitoring data from the Arthropod Program of the Smithsonian Tropical Research Institute (STRI) on Barro Colorado Island (BCI), Panama, we compare whether known arthropod diversity can be detected through metabarcoding of bulk insect samples obtained through automatic light‐trapping. Our study detected 4402 species based on Barcode Index Numbers (BIN) and detected fine‐scale differences between wet and dry seasons and sampling localities. We further refined our analysis to indicate which families and genera explained seasonal turnover. Using samples collected in parallel, but sorted manually as part of the ongoing arthropod monitoring program, we compared these methods. Out of 538 BINs recovered through manual sorting, there was a 70% overlap with the metabarcoding data; however, it represented 30% of the total BINs detected through metabarcoding. Expecting higher detection through metabarcoding, we also compare the results with the 14 years of sampling in BCI to better understand how well the monitoring program has captured the diversity of focal groups. Our results revealed a ~50% overlap between both methods and similar total catch. Barcode Index Numbers manually detected but not recovered by metabarcoding highlight some of the limitations of molecular detection methods such as primer bias. Contrastingly, BINs detected with metabarcoding, but not recovered by the traditional monitoring scheme, highlight the importance of local and regional barcode reference libraries.

Mating strategies of Vitex negundo L. var. heterophylla (Franch.) Rehder (Lamiaceae): A mixed mating system with inbreeding depression.

Plant reproductive ecology is one of the research hotspots in ecology. With the increasing attention paid to the conservation of plant diversity, the research on reproductive characteristics and flowering biological characteristics of more species has attracted more attention. However, plant reproduction is affected by multiple interacting factors such as pollen limitation and resource availability. Vitex negundo var. heterophylla (Franch.) Rehder (Lamiaceae) is a significant species for water and soil conservation. Previous studies have revealed its mating system by the biological characteristics of flowering and SSR markers, but its reproductive strategies remain to be further studied. We evaluated reproductive success through artificial pollination to explore the reproductive characteristics of V. negundo var. heterophylla for the first time. From the results of fruit set, there is a mixed mating system dominated by outcrossing in V. negundo var. heterophylla accompanied by self-compatibility, and it cannot carry out autonomous selfing. Our data show the pollinator-mediated interaction in the success of reproduction, whereas the effect of anemophily is very weak. And the seed germination rate of inbred line progenies was lower than that of hybrid progenies, which is suspected to be caused by inbreeding depression. The research will provide scientific information for the protection and conservation of V. negundo var. heterophylla from the point of view of reproduction. In sum, the results are necessary to protect animal vectors in the background of insect decline.

Filling knowledge gaps in insect conservation by leveraging genetic data from public archives.

Insect decline has become a growing concern in recent years, with studies showing alarming declines in populations of several taxa. Our knowledge about genetic spatial patterns and evolutionary history of insects still exhibits significant gaps hindering our ability to effectively conserve and manage insect populations and species. Genetic data may provide valuable insights into the diversity and the evolutionary relationships of insects' species and populations. Public repositories, such as GenBank and BOLD, containing vast archives of genetic data with associated metadata, offer an irreplaceable resource for researchers contributing to our understanding of species diversity, population structure and evolutionary relationships. However, there are some issues in using these data, as they are often scattered and may lack accuracy due to inconsistent sampling protocols and incomplete information. In this paper we describe a curated georeferenced database of genetic data collected in GenBank and BOLD, for insects listed in the International Union for Conservation of Nature (IUCN) Italian Red Lists (dragonflies, bees, saproxylic beetles and butterflies). After querying these repositories, we performed quality control and data standardization steps. We created a dataset containing approximately 33 000 mitochondrial sequences and associated metadata about taxonomy, collection localities, geographic coordinates and IUCN Red List status for 1466 species across the four insect lists. We describe the current state of geographical metadata in queried repositories for species listed under different conservation status in the Italian Red Lists to quantify data gaps posing barriers to prioritization of conservation actions. Our curated dataset is available for data repurposing and analysis, enabling researchers to conduct comparative studies. We emphasize the importance of filling knowledge gaps in insect diversity and distribution and highlight the potential of this dataset for promoting other research fields like phylogeography, macrogenetics and conservation strategies. Our database can be downloaded through the Zenodo repository in SQL format. Database URL: https://zenodo.org/records/8375181.

The angiosperm radiation played a dual role in the diversification of insects and insect pollinators

Interactions with angiosperms have been hypothesised to play a crucial role in driving diversification among insects, with a particular emphasis on pollinator insects. However, support for coevolutionary diversification in insect–plant interactions is weak. Macroevolutionary studies of insect and plant diversities support the hypothesis that angiosperms diversified after a peak in insect diversity in the Early Cretaceous. Here, we used the family-level fossil record of insects as a whole, and insect pollinator families in particular, to estimate diversification rates and the role of angiosperms on insect macroevolutionary history using a Bayesian process-based approach. We found that angiosperms played a dual role that changed through time, mitigating insect extinction in the Cretaceous and promoting insect origination in the Cenozoic, which is also recovered for insect pollinator families only. Although insects pollinated gymnosperms before the angiosperm radiation, a radiation of new pollinator lineages began as angiosperm lineages increased, particularly significant after 50 Ma. We also found that global temperature, increases in insect diversity, and spore plants were strongly correlated with origination and extinction rates, suggesting that multiple drivers influenced insect diversification and arguing for the investigation of different explanatory variables in further studies.

Crossing Old Concepts: The Ecological Advantages of New Vineyard Types

In times of global insect decline, agricultural ecosystems need to be designed in an as insect-friendly manner as possible to halt the progressive loss of biodiversity. This is particularly important for steep-slope viticulture being established on sites with high biodiversity potential. Therefore, we compared different vineyard types (cross-slope with greened embankments vs. down-slope or other types without greened embankments), using wild bees and butterflies as indicators for biodiversity in the lower Moselle region (SW Germany). The numbers of species and individuals in both groups were significantly higher in cross-slope vineyards with greened embankments. This also held true for the number of specialised and endangered species. The communities of wild bees and butterflies differed remarkably between the vineyard types. Three wild bee and five butterfly species were identified as indicator species and hence can be used as such for further monitoring. Our results underline that the structure of steep-slope vineyards has tremendous importance for biodiversity conservation. Since the cultivation of cross-slope vineyards on steep slopes is easier than that of down-slope vineyards, we assume the great synergistic potential to reconcile agricultural use and biodiversity conservation and, in addition, to preserve steep-slope viticulture as a structural element in landscape planning.

A Systematic Review of Insect Decline and Discovery: Trends, Drivers, and Conservation Strategies over the past Two Decades

Insects make up 75%–80% of all known animal species, with estimates ranging from 10 to 30 million, of which approximately 1.11–1.7 million are described. Despite varying estimates, 80% of insect species remain undiscovered. Unfortunately, insect populations have been declining globally in recent decades, which have significant implications for the overall health of ecosystems. Thus, this review article delves into the status of insects, exploring the causes behind their decline, highlighting discoveries made in recent years, and emphasizing the profound impact of this decline on ecosystems. Furthermore, it discusses the urgent need for conservation efforts and identifies promising areas for future insect research. To achieve these objectives, the researcher uses a systematic review of 156 distinct journals and websites. Insect decline is a worldwide issue caused by habitat loss, pesticide use, pollution, invading species, intensive agriculture, and climate change. It affects flying, ground, and aquatic lineages, with Lepidoptera, Hymenoptera, Coleoptera, Odonata, Plecoptera, Trichoptera, and Ephemeroptera being especially vulnerable. The decline of insects has significant impacts on ecosystems, including food chains, pollination, and nutrient cycling. Insect conservation strategies involve habitat restoration, sustainable land management, species‐specific conservation, and policy. Developing insect conservation laws, enforcing environmental laws, and promoting public education are also crucial for addressing insect declines and promoting biodiversity. Future research should focus on using insects for sustainable agriculture, understanding their behavior for conservation and technology, utilizing insect genetics for pest control, and improving insect classification for conservation.

The Relationship between Two Specific Views in Islamic Theology and Environmental Destruction

The planet is facing an unprecedented and dangerous environmental crisis, environmental problems such as consumerism, increase in human population, soil erosion, drought, drying up of rivers and lakes, destruction of forests and plants, extinction of insects and animals, use of fossil fuels, greenhouse gas production, etc. Muslim countries such as Iran, Iraq, Syria, Lebanon, Yemen, Somalia, Afghanistan, Pakistan, Bangladesh, Indonesia, Kazakhstan, Uzbekistan, Egypt, Libya, and Sudan are also heavily involved with these problems. In Islamic theology, there are two influential approaches to the behavior of Muslims, which have caused the destruction of the environment in Islamic countries. The first approach is the Anthropocentric doctrine in Islamic theology. According to this view, Muslims believe that man is the supreme being on earth and God’s successor on it (Khalīfa Allāh), and everything on earth is created for man’s use. The second approach is the Apocalyptic attitude (ākhir al-zamān) in Islamic theology. This view has also had an inappropriate effect on the behavior of Muslims toward the environment, because according to this approach, Muslims are waiting for the occurrence of Apocalyptic events that will lead to the destruction of the earth, and consequently in the end, the environment will be completely destroyed. For protecting the environment in Islamic countries, these two very influential attitudes toward the behavior of Muslims must be changed.

Well known indicator groups do not predict the decline of insects

In decision making for insect conservation, one depends largely on knowledge of the relationship between changes in environmental factors and abundance of a very limited number of species. The species we have knowledge on cannot be regarded as a representative sample of all insects. How accurately do changes in the abundance of these species predict the changes in other species? To answer this question, we studied 373 insect species belonging to the Apidae (bees), Lepidoptera (butterflies), Orthoptera (grasshoppers), Ephemeroptera (mayflies), Trichoptera (caddisflies), Odonata (dragonflies), and Plecoptera (stoneflies), with known population trends and attributes in the Netherlands. The 78 attributes included morphological and demographic trait values, as well as habitat requirements of species. We trained Random Forests (RFs) with random samples and with taxonomic groups to predict the decline of the species based on their attributes. Then we used the trained RFs to predict the decline of the species outside the training groups and checked the accuracy of the predictions. The results showed that accuracy of the predictions of the RFs trained by the random samples increased from 0 to 0.20 (maximum 0.40, on a scale of 0 to 1) with sample size increasing from 10 to 90% of the insects. Moreover, we found that the accuracy of the predictions by the RFs trained with the taxonomic groups were zero in case of butterflies and grasshoppers, and low in other groups (maximum 0.37, in case of bees predicting terrestrial insects). Accuracy depended significantly on the size of the taxonomic group. Large over- or underestimation of number of declining species occurred in all cases. Further, we found that the taxonomic groups had few attributes important for predicting in common. The attribute ‘Active dispersion’ had the highest importance when all insects were used for training the RF. Using ‘indicator groups’ for predicting the decline of insects has a high risk of over- or underestimating the actual number of declining species and should therefore be advised against unless the indicator group is sure to be representative.

Time-Series Characterization of Grassland Biomass Intensity to Examine Management Change at Two Sites in Germany Using 25 Years of Remote Sensing Imagery

In cultivated landscapes, grasslands are an important land use type for insect life. Grassland management practices can have a significant impact on insect ecology. For example, intense fertilization and frequent cutting can reduce the diversity and abundance of insects by destroying their habitat and food sources. Thus, the quality of grassland habitat for insect development depends on its management intensity. The intensification of grassland production is discussed as one factor contributing to the decline in insect biomass over recent decades. Characterizing grassland changes over time provides one piece to the larger puzzle of insect decline. We analyzed landscape-level trends in grassland biomass near Orbroich and Wahnbachtal in North Rhine-Westphalia, Germany, over a 25-year period. In both areas, pronounced insect biomass decline had been observed. More than 430 Landsat images were used. An image normalization process was developed and employed to ensure that observed changes over time were attributed to grassland changes and not systemic changes inherent within image time series. Distinct clusters of grassland parcels were identified based on intensity and temporal changes in biomass using Normalized Difference Vegetation Index (NDVI) as an indicator. Cluster separability was confirmed using the Transform Divergence method. The results showed clusters having periods of distinct trends in vegetation biomass, indicating changes in grassland agronomic and/or management practices over time (e.g., fertilization, increased silage production). Changes in management practices coincided with regional trends in cultivation as documented by official statistics. We demonstrated the feasibility of using 100+ images over multiple decades to perform a long-term remote sensing analysis examining grassland change. These temporally expansive and spatially detailed trends of grassland change can be included as factors in the multi-variate analysis of insect decline. The methodology can be applied to other geographic areas. Such improved insights can support informed landscape design and cultivation patterns in relation to insect ecology and the broader context of biodiversity enhancement.

Influence of the pesticide flupyradifurone on mobility and physical condition of larval green lacewings.

Global pesticide use in agriculture is one reason for the rapid insect decline in recent years. The relatively new pesticide flupyradifurone is neurotoxic to pest insects but considered harmless to bees according to previous risk assessments. With this study, we aim to investigate lethal and sublethal effects of flupyradifurone on larvae of the beneficial arthropod Chrysoperla carnea. We treated the animals orally with field-realistic concentrations of flupyradifurone and examined lethality as well as effects on condition, mobility and locomotion. For the lethal dose 50, we determined a value of > 120-200ng/mg (corresponding to a mean amount of 219ng/larva) after 168h. Abnormal behaviors such as trembling and comatose larvae were observed even at the lowest concentration applied (> 0-20ng/mg, 59ng/larva). Mobility analysis showed impaired activity patterns, resulting in acute hypoactivity at all pesticide concentrations and time-delayed hyperactivity in larvae treated with > 40-60ng/mg (100ng/larva) and > 80-100ng/mg (120ng/larva), respectively. Even locomotion as a fundamental behavioral task was negatively influenced throughout larval development. In conclusion, our results demonstrate that flupyradifurone impacts life and survival of lacewing larvae and may pose-despite its status as bee-friendly-a major threat to insect fauna and environment.

Earlier and more uniform spring green-up linked to lower insect richness and biomass in temperate forests

Urbanization and agricultural intensification are considered the main causes of recent insect decline in temperate Europe, while direct climate warming effects are still ambiguous. Nonetheless, higher temperatures advance spring leaf emergence, which in turn may directly or indirectly affect insects. We therefore investigated how Sentinel-2-derived start of season (SOS) and its spatial variability (SV-SOS) are affected by spring temperature and whether these green-up variables can explain insect biomass and richness across a climate and land-use gradient in southern Germany. We found that the effects of both spring green-up variables on insect biomass and richness differed between land-use types, but were strongest in forests. Here, insect richness and biomass were higher with later green-up (SOS) and higher SV-SOS. In turn, higher spring temperatures advanced SOS, while SV-SOS was lower at warmer sites. We conclude that with a warming climate, insect biomass and richness in forests may be affected negatively due to earlier and more uniform green-up. Promising adaptation strategies should therefore focus on spatial variability in green-up in forests, thus plant species and structural diversity.

Long-term monitoring and analysis of Brood X cicada activity by distributed fiber optic sensing technology.

Brood X is the largest of the 15 broods of periodical cicadas, and individuals from this brood emerged across the Eastern United States in spring 2021. Using distributed acoustic sensing (DAS) technology, the activity of Brood X cicadas was monitored in their natural environment in Princeton, NJ. Critical information regarding their acoustic signatures and activity level is collected and analyzed using standard outdoor-grade telecommunication fiber cables. We believe these results have the potential to be a quantitative baseline for regional Brood X activity and pave the way for more detailed monitoring of insect populations to combat global insect decline. We also show that it is possible to transform readily available fiber optic networks into environmental sensors with no additional installation costs. To our knowledge, this is the first reported use case of a distributed fiber optic sensing system for entomological sciences and environmental studies.

Evolution of Insect Diversity in the Permian and Triassic

The global warming that occurred during the Permo-Triassic transition, following the end of the Late Paleozoic glaciation, and the resulting responses of the biota to the changing environment, are considered important analogs for understanding rapid future warming scenarios. While there has been extensive research on the patterns and extent of diversity in plants, tetrapods, and marine invertebrates during the Permo-Triassic, the study of insect diversity and the evolution of their faunal composition has been relatively limited. The question of whether there were insect extinctions during this period continues to be a subject of debate. Here, we present a statistical study on taxonomic diversity of insects—at specific, generic and familial levels—throughout the Permian and Triassic, with subsampled context on the reported global occurrences. Our result show that more than one insect extinction events, accompanied by significant diversity drop and turnovers of faunal compositional, occurred in the Permian and Triassic. All the uncovered insect diversity crises exhibit strong correspondence with the well-known marine mass extinction events in the Middle Permian, Permo-Triassic transition, Carnian, and Rhaetian, whilst the marine correspondence with the Early Permian insect crisis is less pronounced. Insects, being a major component of terrestrial ecosystems, demonstrate varied diversity responses to climatic changes in Permian and Triassic. Our study sheds new light on the intricate interplay between insect diversity evolution and the changing environmental conditions during these critical geohistorical periods.